Co-reporter:Chengdong Chen, Shigang Dong, Ruiqing Hou, Juan Hu, Pingli Jiang, Chenqing Ye, Ronggui Du, Changjian Lin
Surface and Coatings Technology 2017 Volume 326, Part A(Volume 326, Part A) pp:
Publication Date(Web):15 October 2017
DOI:10.1016/j.surfcoat.2017.06.031
•A functional bis-amino silane film was prepared on carbon steel by electrodeposition.•CeO2 nanoparticles were adopted to modify the silane film and to be beneficial for electrodeposition.•The silane/CeO2 composite film provided a good protection for carbon steel.•Localized corrosion was investigated by in-situ scanning electrochemical system.A thin film of bis-amino silane of bis-[triethoxysilylpropyl]amine (BTSPA) was coated on carbon steel surface by electrodeposition and then chemically modified by adsorption of CeO2 nanoparticles. The composition and structure of BTSPA/CeO2 composite film were characterized by electron microprobe analysis, X-ray photoelectron spectroscopy and infrared reflection absorption spectroscopy, while the anti-corrosion performance of the composite film on carbon steel was investigated using electrochemical impedance spectroscopy and scanning reference electrode technique. The results demonstrated that the BTSPA/CeO2 composite film formed on the BTSPA film electrodeposited at − 0.8 V vs. SCE, which exhibited an enhanced corrosion protection for carbon steel and an improvement of adhesion between substrate and outer coating. The CeO2 nanoparticles incorporated/absorbed into the SiOSi network of the BTSPA film were able to promote the condensation of hydrolysis product SiOH groups to the SiOSi network on the surface and to provide a barrier and corrosion inhibition properties for carbon steel, which is beneficial for improvement of the corrosion protection of the composite film for carbon steel.
Co-reporter:Yanhui Cao, Shigang Dong, Dajiang Zheng, Jingjing Wang, Xiaojuan Zhang, Ronggui Du, Guangling Song, Changjian Lin
Corrosion Science 2017 Volume 126(Volume 126) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.corsci.2017.06.026
•A multifunctional inhibitor of MgAl-layered double hydroxides loaded with nitrites was synthesized for corrosion control of steel in concrete.•The synthesized LDHs are able to provide a comprehensive protection for steel in both simulated carbonated concrete pore solutions and concrete.•A conceptual model was proposed for presenting the corrosion protection mechanism of such multifunctional inhibitor for reinforced concrete.A novel multifunctional inhibitor of MgAl-layered double hydroxides (LDHs) loaded with nitrite anions was synthesized via a calcination-rehydration in ambient atmosphere without inert gas protection. It was demonstrated that such LDHs loaded with inhibitor was able to efficiently control the corrosion of carbon steel in simulated carbonated concrete pore (SCCP) solution as well as in mortar. Based on the systematic measurements, a conceptual model was proposed to further understand the mechanism of multifunctional corrosion protection of MgAl-LDHs-NO2− in steel reinforced concrete. Such unique multifunctional composite is markedly helpful to comprehensively control corrosion of steel in concrete.
Co-reporter:Jinyan Lin, Zhou Pan, Liang Song, Yanmei Zhang, Yang Li, Zhenqing Hou, Changjian Lin
Applied Surface Science 2017 Volume 425(Volume 425) pp:
Publication Date(Web):15 December 2017
DOI:10.1016/j.apsusc.2017.07.034
•For its intrinsic amphiphilic property, the IND prodrug self-assembled into NPs in aqueous solution and served two roles-as an anti-inflammatory prodrug and a drug carrier.•The constructed IND-PEG-IND NPs had naoscaled particle size of approximately 80 nm, negative surface, spherical shape, and good water-dispersity.•IND-PEG-IND NPs demonstrated sustained and cathepsin B-controlled drug release behavior.•More importantly, IND-PEG-IND NPs significantly reduced the acute totoxicity agaist normal osteoblast cells compared to the free IND.Despite the great efficacy of indomethacin (IND) as an anti-inflammatory agent, its clinical translation has been obstructed by the water insolubility, severe side effects, and exceedingly low bioavailability. Indomethacin prodrug-based nanoparticles (NPs) combining the strengths of both nanotechnology and prodrugs that might overcome this crucial problem are presented. Here, using the carbodiimide-mediated couple reaction, IND was conjugated to clinically approved poly(ethylene glycol) (PEG) polymer via peptide linkage that was cleavaged in the presence of cathepsin B, which was significantly induced after inflammatory. The synthesized IND-PEG-IND conjugate was characterized by UV–vis, FTIR, 1H NMR, XRD, and MALDI-TOF-MS analyses. For its intrinsic amphiphilic property, the IND prodrug self-assembled into NPs in aqueous solution and served two roles-as an anti-inflammatory prodrug and a drug carrier. The constructed IND-PEG-IND NPs had naoscaled particle size of approximately 80 nm, negative surface, spherical shape, good water-dispersity, and high and fixed drug-loading content of 20.1 wt%. In addition, IND-PEG-IND NPs demonstrated sustained and cathepsin B-controlled drug release behavior. More importantly, IND-PEG-IND NPs significantly reduced the acute totoxicity agaist normal osteoblast cells and displayed the more potent anti-inflammatory effect against macrophage cells compared to the free IND. Taken together, the nanoprodrug might exhibit increased potency for nanomedicine-prospective therapeutic use in clinical treatement of implant inflammatory diseases.
Co-reporter:Qiaoling Huang, Yun Yang, Dajiang Zheng, Ran Song, ... Changjian Lin
Acta Biomaterialia 2017 Volume 51(Volume 51) pp:
Publication Date(Web):15 March 2017
DOI:10.1016/j.actbio.2017.01.044
Blood compatibility of TiO2 nanotubes (TNTs) has been assessed in rabbit platelet-rich plasma (PRP), which combines activation of both blood plasma coagulation and platelets. We find that (i) amorphous TiO2 nanotubes (TNTs) with relatively larger outer diameters led to reduced platelet adhesion/activation, (ii) TNTs with relatively smaller outer diameters in a predominately rutile phase also inhibited platelet adhesion and activation, and (iii) a pervasive fibrin network formed on larger outer diameter TNTs in a predominately anatase phase. Thus, this study suggests that combined effect of crystalline phase and surface chemistry controls blood-contact behavior of TNTs. A more comprehensive mechanism is proposed for understanding hemocompatibility of TiO2 which might prove helpful as a guide to prospective design of TiO2-based biomaterials.Statement of SignificanceTo realize optimal design and construction of biomaterials with desired properties for blood contact materials, a comprehensive understanding of structure-property relationships is required. In the existing literature, TiO2 nanotube has been reported to be a good candidate for biomedical applications. However, it is noticeable that the blood compatibility of TiO2 nanotubes (TNTs) remains obscure or even inconsistent in the previously published works. The inconsistency could derive from different research protocols, material properties or blood sources. Thus, a thorough investigation of the effect of surface properties on blood compatibility is crucial to the development of titanium based materials. In this paper, we explored the effect of surface properties on the response of platelet-rich plasma, especially surface morphology, chemistry, wettability and crystalline phase. The results indicated that crystalline phase was a dominant factor in platelet behaviors. Reduced adhesion and activation of platelets were observed on amorphous and rutile dominated TNTs, whereas anatase dominated TNTs activated the formation of fibrin network. We further proposed a hypothetical mechanism for better understanding of how surface properties affect the response of platelet-rich plasma. Therefore, this study expands the fundamental understanding of the structure-property relationships of titanium based materials.Download high-res image (309KB)Download full-size image
Co-reporter:Zhi Wu;Cheng Gong;Jiangdong Yu;Lan Sun;Wang Xiao
Journal of Materials Chemistry A 2017 vol. 5(Issue 3) pp:1292-1299
Publication Date(Web):2017/01/17
DOI:10.1039/C6TA07420K
Photoelectrocatalytic efficiency is mainly dependent on the light absorption of a photocatalyst electrode, charge separation and transport, and surface chemical reactions. To enhance photoelectrocatalytic efficiency, an ordered one-dimensional heterojunction photocatalyst consisting of CuxZn1−xIn2S4 ultrathin nanosheets on electrochemically anodized TiO2 nanotube arrays (CZIS@TNTAs) was successfully synthesized by a solvothermal reaction. It was found that the CuxZn1−xIn2S4 ultrathin nanosheets on the TNTAs significantly enhanced visible light absorption and photoelectrochemical responses, and a near 8.0-fold increase in the photoelectrocatalytic hydrogen production rate was achieved compared to the blank TNTAs. Moreover, the CZIS@TNTAs exhibited excellent photoelectrocatalytic stability. Measurements of the flat-band and electrochemical impedance revealed the feasibility of charge transfer in the CZIS@TNTA hetero-systems, which was supported by PL and photoelectrochemical measurements. The superior photoelectrocatalytic activity of the CZIS@TNTA composite electrodes is mainly attributed to their enhanced light absorption and the separation of photo-generated charges, facilitating electron transport along the 1D TiO2 structure.
Co-reporter:Yun Yang;Yanmei Zhang;Ren Hu;Qiaoling Huang;Ke Wu;Lihai Zhang;Peifu Tang
RSC Advances (2011-Present) 2017 vol. 7(Issue 61) pp:38434-38443
Publication Date(Web):2017/08/02
DOI:10.1039/C7RA06449G
The increasing threat of orthopedic implant failure caused by infection and loosening intensifies the need for novel surface functional treatment. In this study, a thin mussel adhesive protein (Mefp-1)/silver nanoparticle (AgNP) composite film constructed on titania nanotubes (TNTs) via a simple dip-coating method has been demonstrated. The TNT/Mefp-1/AgNP coating exhibits both high antibacterial activity and adequate cytocompatibility. The adherent Mefp-1 film could promote preosteoblast proliferation and reduce AgNP-induced cytotoxicity. The AgNPs (∼10 nm) constructed with the assistance of Mefp-1 are effective for the elimination of both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) via a combination of contact-killing and release-killing modes. This facile and mild functionalization strategy exhibits promising applications in surface antibacterial modifications, especially in three-dimensional sophisticated medical devices.
Co-reporter:Meidan Ye;Xiaoyue Gao;Xiaodan Hong;Qun Liu;Chunfeng He;Xiangyang Liu
Sustainable Energy & Fuels (2017-Present) 2017 vol. 1(Issue 6) pp:1217-1231
Publication Date(Web):2017/07/25
DOI:10.1039/C7SE00137A
Quantum dot-sensitized solar cells (QDSCs), as promising candidates for cost-effective photoelectrochemical solar cells, have attracted much attention due to their characteristic properties such as processability at low cost, feasibility to control light absorption spectrum in a wide region, and possibility of multiple electron generation with a theoretical conversion efficiency up to 44%. QDSCs have analogous structures to dye-sensitized solar cells typically consisting of semiconductor photoanodes sensitized with quantum dots (QDs), redox electrolytes, and counter electrodes (CEs). Much effort has been dedicated to optimizing each component of QDSCs for higher device performance. In this review, recent advances of photoanodes with various architectures, QDs with tunable band gaps, electrolytes in liquid, quasi-solid or solid state, and CEs with great electrocatalytic activity for QDSCs will be highlighted. We aim to elaborate the rational strategies in material design for QDSC applications. Finally, the conclusion and future prospects emphasize the key developments and remaining challenges for QDSCs.
Co-reporter:Mengye Wang, Xinchang Pang, Dajiang Zheng, Yanjie He, Lan Sun, Changjian Lin and Zhiqun Lin
Journal of Materials Chemistry A 2016 vol. 4(Issue 19) pp:7190-7199
Publication Date(Web):18 Mar 2016
DOI:10.1039/C6TA01838F
The ability to synthetically tune the size, shape, composition and architecture of inorganic nanostructures offers enormous opportunities to explore the fundamental structure–property relationships that occur uniquely at the nanoscale, and engineer greater functionality and design complexity into new material systems. Core/shell nanoparticles represent an important class of nanostructured materials that have garnered considerable interest. The success in producing core/shell nanoparticles with strictly controlled core diameter and shell thickness and tailoring their material properties relies crucially on the epitaxial growth of the shell material over the highly curved surface of the spherical core. However, effective methods to yield such high-quality core/shell nanoparticles are comparatively few and limited in scope. Here, we develop a robust nonepitaxial growth strategy to create uniform plasmonic/semiconducting core/shell nanoparticles with precisely controlled dimensions by capitalizing on amphiphilic star-like triblock copolymers as nanoreactors. The diameter of the plasmonic core and the thickness of the semiconductor shell can be independently and precisely regulated by tailoring the molecular weights (i.e., the lengths) of the inner and intermediate blocks of star-like triblock copolymers, respectively. The successful crafting of plasmonic/semiconducting core/shell nanoparticles was corroborated by the composition and structural characterizations. These functional nanoparticles exhibited largely improved photocatalytic activities, which can be attributed to the localized surface plasmon-mediated light harvesting enhancement of the plasmonic core and the built-in internal electric field. This nonepitaxial growth strategy offers new levels of tailorability in the dimensions, compositions and architectures of nanomaterials with engineered functionalities for applications in catalytic, electronic, optic, optoelectronic and sensory materials and devices.
Co-reporter:Ran Song, Jianhe Liang, Longxiang Lin, Yanmei Zhang, Yun Yang and Changjian Lin
Journal of Materials Chemistry A 2016 vol. 4(Issue 22) pp:4017-4024
Publication Date(Web):06 May 2016
DOI:10.1039/C6TB00458J
Base on a superhydrophobic–superhydrophilic micro-patterned template, a facile construction of gradient micro-patterned octacalcium phosphate (OCP) coatings on titanium has been firstly developed for high-throughput evaluation of biocompatibility. The gradient OCP coatings with tunable crystal morphologies involving scattered-flower-like, scattered-flower-ribbon-like, short-ribbon-like and long-ribbon-like were fabricated in different micro-units on the same surface. The significant difference of mineralization behavior of the gradient OCP coatings in the micro-patterns was observed visually and efficiently. In vitro cultures of MC3T3-E1 cells showed that the number and morphology of cells selectively adhered on the micro-units of gradient structure of OCP coatings were distinctly different, indicating that the cells are sensitive to the different structures of OCP coatings on medical titanium. The gradient micro-patterned construction is potentially a powerful method for not only high-throughput screening of the biocompatibility of various biomaterials, but also efficient development of advanced biomaterials by controlling cell immobilization and inducing cell response.
Co-reporter:Mengye Wang;Meidan Ye;James Iocozzia;Zhiqun Lin
Advanced Science 2016 Volume 3( Issue 6) pp:
Publication Date(Web):
DOI:10.1002/advs.201600024
Plasmonics has remained a prominent and growing field over the past several decades. The coupling of various chemical and photo phenomenon has sparked considerable interest in plasmon-mediated photocatalysis. Given plasmonic photocatalysis has only been developed for a relatively short period, considerable progress has been made in improving the absorption across the full solar spectrum and the efficiency of photo-generated charge carrier separation. With recent advances in fundamental (i.e., mechanisms) and experimental studies (i.e., the influence of size, geometry, surrounding dielectric field, etc.) on plasmon-mediated photocatalysis, the rational design and synthesis of metal/semiconductor hybrid nanostructure photocatalysts has been realized. This review seeks to highlight the recent impressive developments in plasmon-mediated photocatalytic mechanisms (i.e., Schottky junction, direct electron transfer, enhanced local electric field, plasmon resonant energy transfer, and scattering and heating effects), summarize a set of factors (i.e., size, geometry, dielectric environment, loading amount and composition of plasmonic metal, and nanostructure and properties of semiconductors) that largely affect plasmonic photocatalysis, and finally conclude with a perspective on future directions within this rich field of research.
Co-reporter:Ping-Li Jiang, Rui-Qing Hou, Cheng-Dong Chen, Lan Sun, Shi-Gang Dong, Jin-Shan Pan, Chang-Jian Lin
Journal of Colloid and Interface Science 2016 Volume 478() pp:246-255
Publication Date(Web):15 September 2016
DOI:10.1016/j.jcis.2016.06.001
To control the degradation rate of medical magnesium in body fluid environment, biocompatible films composed of Mussel Adhesive Protein (Mefp-1) and chitosan were electrodeposited on magnesium surface in cathodic constant current mode. The compositions and structures of the films were characterized by atomic force microscope (AFM), scanning electron microscope (SEM) and infrared reflection absorption spectroscopy (IRAS). And the corrosion protection performance was investigated using electrochemical measurements and immersion tests in simulated body fluid (Hanks’ solution). The results revealed that Mefp-1 and chitosan successfully adhered on the magnesium surface and formed a protective film. Compared with either single Mefp-1 or single chitosan film, the composite film of chitosan/Mefp-1/chitosan (CPC (chitosan/Mefp-1/chitosan)) exhibited lower corrosion current density, higher polarization resistance and more homogenous corrosion morphology and thus was able to effectively control the degradation rate of magnesium in simulated body environment. In addition, the active attachment and spreading of MC3T3-E1 cells on the CPC film coated magnesium indicated that the CPC film was significantly able to improve the biocompatibility of the medical magnesium.A composite film of chitosan/Mefp-1/chitosan was electrodeposited on Mg surface, which exhibited continually increased corrosion resistance, controlled the degradation rate of Mg and elevated the biocompatibility of the substrate greatly.
Co-reporter:Licheng Zhang;Lihai Zhang;Yun Yang;Wei Zhang;Houchen Lv;Fei Yang;Peifu Tang
Journal of Biomedical Materials Research Part B: Applied Biomaterials 2016 Volume 104( Issue 5) pp:1004-1012
Publication Date(Web):
DOI:10.1002/jbm.b.33454
Abstract
The antibacterial properties of super-hydrophobic silver (Ag) on implant surface have not yet to be fully illuminated. In our study, we investigate the protective effects of super-hydrophobic coating of silver/titanium dioxide (Ag/TiO2) nanotubes against bacterial pathogens, as well as its pattern of Ag release. Ag/TiO2 nanotubes are prepared by a combination of electrochemical anodization and pulse electrodeposition. The super-hydrophobic coating is prepared by modifying the surface of Ag/TiO2 nanotubes with 1H, 1H, 2H, 2H-perfluorooctyl-triethoxysilane (PTES). Surface features and Ag release are examined by SEM, X-ray photoelectron spectroscopy, contact-angle measurement, and inductively coupled plasma-mass spectrometry (ICP-MS). The antibacterial activity of super-hydrophobic coating Ag/TiO2 nanotubes is investigated both in vitro and in vivo. Consequently, the super-hydrophobic coating on Ag/TiO2 nanotubes shows a regularly arranged structure; and nano-Ag particles (10–30 nm) are evenly distributed on the surface or inside the nanotubes. The contact angles of water on the super-hydrophobic coating Ag/TiO2 nanotubes are all above 150°. In addition, the super-hydrophobic character displays a certain conserved effect that contributes to the sustained release of Ag. The super-hydrophobic Ag/TiO2 nanotubes are also effective in inhibiting bacterial adhesion, killing the adhering bacteria and preventing postoperative infection in rabbits. Therefore, it is expected that the super-hydrophobic Ag/TiO2 nanotubes which can contain the release of Ag, leading to stable release, may show a consistent surface antibacterial capability. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1004–1012, 2016.
Co-reporter:Rui-Qing Hou;Chen-Qing Ye;Cheng-Dong Chen
Acta Metallurgica Sinica (English Letters) 2016 Volume 29( Issue 1) pp:46-57
Publication Date(Web):2016 January
DOI:10.1007/s40195-015-0361-2
To further understand the localized corrosion of magnesium alloy, various in situ electrochemical techniques and ex situ electron microprobe analysis and SEM were used to monitor the corrosion process of Mg–1.0Ca alloy in 0.9 wt% sodium chloride solution. The results indicated that the localized corrosion was accompanied by the formation and thickening of a corrosion product film on the Mg–1.0Ca alloy. A localized corrosion of the alloy initiated selectively on the eutectic micro-constituent zones, then enhanced with the exposure, developed in depth with ring-shaped corrosion products accumulated around and finally formed a volcanic-like pitting. Based on the measurements, an electrochemical corrosion model was proposed accordingly to describe the formation mechanism of the volcanic-like pitting on the alloy in 0.9 wt% sodium chloride solution.
Co-reporter:Qiaoling Huang, Martin Antensteiner, Xiang Yang Liu, Changjian Lin, Erwin A. Vogler
Colloids and Surfaces B: Biointerfaces 2016 Volume 148() pp:211-219
Publication Date(Web):1 December 2016
DOI:10.1016/j.colsurfb.2016.07.022
•A readily qualitative, graphical analysis of cell adhesion kinetics is aplied.•Cell adhesion kinetic parameters strongly depend on substratum surface energy.•Cell adhesion to hydrophobic surfaces is “slow-and-low”.•Cell adhesion to hydrophilic counterparts is “fast-and-high”.•A sharp hydrophobic/hydrophilic contrast in bioadhesion is observed.Short-term ( < 2 h) cell adhesion kinetics of 3 different mammalian cell types: MDCK (epithelioid), MC3T3-E1 (osteoblastic), and MDA-MB-231 (cancerous) on 7 different substratum surface chemistries spanning the experimentally-observable range of water wettability (surface energy) are graphically analyzed to qualitatively elucidate commonalities and differences among cell/surface/suspending media combinations. We find that short-term mammalian cell attachment/adhesion in vitro correlates with substratum surface energy as measured by water adhesion tension, τ≡γlvcosθτ≡γlvcosθ, where γlvγlv is water liquid-vapor interfacial energy (72.8 mJ/m272.8 mJ/m2) and cosθcosθ is the cosine of the advancing contact angle subtended by a water droplet on the substratum surface. No definitive functional relationships among cell-adhesion kinetic parameters and ττ were observed as in previous work, but previously-observed general trends were reproduced, especially including a sharp transition in the magnitude of kinetic parameters from relatively low-to-high near τ=0τ=0 mJ/m2, although the exact adhesion tension at which this transition occurs is difficult to accurately estimate from the current data set. We note, however, that the transition is within the hydrophobic range based on the τ=30τ=30 mJ/m2 surface-energetic dividing line that has been proposed to differentiate “hydrophobic” surfaces from “hydrophilic”. Thus, a rather sharp hydrophobic/hydrophilic contrast is observed for cell adhesion for disparate cell/surface combinations.
Co-reporter:Meidan Ye, Xiaoru Wen, Mengye Wang, James Iocozzia, Nan Zhang, Changjian Lin, Zhiqun Lin
Materials Today 2015 Volume 18(Issue 3) pp:155-162
Publication Date(Web):April 2015
DOI:10.1016/j.mattod.2014.09.001
Dye-sensitized solar cells (DSSCs), as low-cost photovoltaic devices compared to conventional silicon solar cells, have received widespread attention in recent years; although much work is required to reach optimal device efficiencies. This review highlights recent developments in DSSCs and their key components, including the photoanode, sensitizer, electrolyte and counter electrode.
Co-reporter:Dajiang Zheng, Xinchang Pang, Mengye Wang, Yanjie He, Changjian Lin, and Zhiqun Lin
Chemistry of Materials 2015 Volume 27(Issue 15) pp:5271
Publication Date(Web):July 21, 2015
DOI:10.1021/acs.chemmater.5b01422
Atom transfer radical polymerization (ATRP) of 4-vinylpyridine, t-butyl acrylate, and styrene in sequential order from a β-cyclodextrin core yielded an amphiphilic star-like triblock copolymer, poly(4-vinylpyridine)-block-poly(t-butyl acrylate)-block-polystyrene (P4VP-b-PtBA-b-PS). Subsequently, star-like triblock copolymer composed of inner hydrophilic P4VP blocks, central hydrophobic PtBA blocks, and outer hydrophobic PS blocks with well-defined molecular architecture and molecular weight of each block was judiciously exploited as nanoreactor for synthesis of precisely shaped hairy plasmonic/semiconductor Au/TiO2 core/shell nanoparticles. The resulting Au/TiO2 nanoparticles were intimately and permanently tethered with outer PS chains that enabled the superior solubility of nanoparticles in nonpolar solvents. The PS chains on the surface of these bifunctional nanoparticles were carbonized by annealing in an inert atmosphere (i.e., yielding carbon-coated Au/TiO2 nanoparticles). In comparison to a widely used TiO2 network film (i.e., P25)-based device, dye-sensitized solar cells assembled by incorporating a thin layer of carbonized Au/TiO2 nanoparticles on the top of P25 film as photoanode exhibited largely improved short-circuit current density, JSC (18.4% increase), and power conversion efficiency, PCE (13.6% increase), respectively. Such improvements were attributed to the surface plasmon-enabled light harvesting enhancement of Au core and fast electron transport promoted by the carbon layer coating on Au/TiO2 nanoparticles, as revealed by external quantum efficiency (EQE), UV–vis spectroscopy, and electrochemical impedance spectroscopy measurements, respectively.
Co-reporter:Meidan Ye, Xiaoru Wen, Nan Zhang, Wenxi Guo, Xiangyang Liu and Changjian Lin
Journal of Materials Chemistry A 2015 vol. 3(Issue 18) pp:9595-9600
Publication Date(Web):16 Mar 2015
DOI:10.1039/C5TA00390C
Vertical CuS nanosheet arrays were synthesized in situ for the first time on transparent conducting fluorine-doped tin oxide (FTO) substrates via a facile solvothermal process of seeded FTO glasses in the presence of ethanol solvent only containing thiourea and Cu(NO3)2 as a precursor. While choosing CuCl instead of Cu(NO3)2 as the copper precursor in the same solvothermal process, porous Cu1.8S nanosheets, for the first time, were also vertically grown on FTO substrates, suggesting that such a synthesis process is a general approach for the preparation of copper sulfide nanosheet arrays. When used as low-cost counter electrode materials in quantum dot-sensitized solar cells (QDSSCs), CuS (3.95%) and Cu1.8S (3.30%) nanosheet films exhibited enhanced power conversion efficiencies in comparison with the conventional Pt film (1.99%), which was primarily due to the excellent electrocatalytic activity of copper sulfides for the reduction of the polysulfide electrolyte used in CdSe/CdS QDSSCs. Significantly, the in situ growth strategy largely simplified the fabrication procedure of copper sulfide counter electrodes and, meanwhile, enhanced the adhesion between films and substrates.
Co-reporter:Chang Chen, Meidan Ye, Nan Zhang, Xiaoru Wen, Dajiang Zheng and Changjian Lin
Journal of Materials Chemistry A 2015 vol. 3(Issue 12) pp:6311-6314
Publication Date(Web):09 Feb 2015
DOI:10.1039/C4TA06987K
Hollow Co9S8 nanoneedle arrays directly grown on fluorine-doped tin oxide (FTO) transparent conducting substrates were successfully prepared using a simple sacrificial template method. The performances of CdS/CdSe quantum dot-sensitized solar cells (QDSCs) employing such Co9S8 counter electrodes were remarkably improved compared to those using conventional Pt counter electrodes, primarily due to their higher electrocatalytic activity in the reduction of polysulfide electrolytes.
Co-reporter:Pinliang Jiang, Jianhe Liang, Ran Song, Yanmei Zhang, Lei Ren, Lihai Zhang, Peifu Tang, and Changjian Lin
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 26) pp:14384
Publication Date(Web):June 15, 2015
DOI:10.1021/acsami.5b03172
Surface structures and properties of titanium implants play a vital role in successful bone replacement. To mimic the natural bone structure, some strategies have recently focused on the preparation of multiscaled morphology on medical titanium and shown some promising results; however, relatively few efforts have been made for further enhancing the biocompatibility of such a hierarchical hybrid structure without compromising the superior bioactivity of the starting micro/nano roughness. In this study, a thin ribbonlike octacalcium phosphate (OCP) coating was electrodeposited on a hierarchically structured titania surface, maintaining its micro/nanospongelike morphology. It is indicated that the micro/nanostructured surface with deposited OCP showed an improved biomineralization ability, in comparison to that without OCP modification, when immersed in simulated body fluid (SBF). Further evaluations of cellular activities demonstrated that the introduction of OCP to the micro/nano spongelike-structured surface remarkably enhanced MC3T3-E1 cell proliferation, alkaline phosphatase activity, and extracellular matrix mineralization compared to that of cells on the micro/nanospongelike titania surface during 14 days of culturing. Meanwhile, the OCP-deposited micro/nanostructured surface displayed much a smaller passive current density and lower current response to the applied potential, resulting in the improvement of corrosion resistance. All of the evaluations suggested that the modification of the OCP coating on the prepared micro/nanospongelike titania is of superior chemical stability, biomineralization, and osteoblast activities, which indicates a favorable implant microenvironment for osseointegration in vivo.Keywords: apatite; cellular activities; corrosion resistance; octacalcium phosphate; titania;
Co-reporter:Dajiang Zheng;Meidan Ye;Xiaoru Wen;Nan Zhang
Science Bulletin 2015 Volume 60( Issue 9) pp:850-863
Publication Date(Web):2015 May
DOI:10.1007/s11434-015-0769-0
Dye-sensitized solar cell (DSSC) is one of the most rapidly developed solar cells in the past 20 years. Many characterization methods have been employed for further understanding the operational details of the photoelectric conversion in DSSC as well as the evaluation of cell performance. Electrochemical methods have become powerful tools for studying the charge transfer and interfacial process. In this review, we introduce and explain the various electrochemical methods used to characterize and analyze DSSC, including current–voltage (I–V) scan measurement, cyclic voltammetry, electrochemical impedance spectroscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy. In addition, some applications were provided as samples to elucidate electron transfer kinetics, energy levels and electrocatalytic activity of the materials used in DSSC.染料敏化太阳能电池(DSSC)在过去的20几年间发展迅速,由于DSSC本质上是一类电化学太阳能电池,电化学研究方法无论在DSSC的性能表征,还是在研究电池机理、电荷转移和界面过程等方面均可发挥重要作用。本文着重介绍了多种常用电化学方法的原理及其在染料敏化太阳能电池表征及研究中的应用,包括线性伏安扫描、循环伏安、电化学阻抗及新型的电化学频谱技术,如强度调制光电流谱、强度调制光电压谱等。特别是从实用的角度通过结合具体实例,阐明电化学方法在DSSC的性能表征、电池工作机制、电荷转移和界面过程研究等方面的应用。
Co-reporter:Meidan Ye;Chang Chen;Nan Zhang;Xiaoru Wen;Wenxi Guo
Advanced Energy Materials 2014 Volume 4( Issue 9) pp:
Publication Date(Web):
DOI:10.1002/aenm.201301564
Hierarchical Cu2S microspheres wrapped by reduced graphene oxide (RGO) nanosheets are prepared via a one-step solvothermal process. The amount of graphene oxide used in the synthesis process has a remarkable effect on the features of Cu2S microspheres. Compared to Pt and Cu2S electrodes, RGO-Cu2S electrodes show better electrocatalytic activity, greater stability, lower charge-transfer resistance, and higher exchange current density. As expected, RGO-Cu2S electrodes exhibit superior performance when functioning as counter electrodes in CdS/CdSe quantum dot-sensitized solar cells (QDSSCs) using a polysulfide electrolyte. A power conversion efficiency up to 3.85% is achieved for the QDSSC employing an optimized RGO-Cu2S counter electrode, which is higher than those of the QDSSCs featuring Pt (2.14%) and Cu2S (3.39%) counter electrodes.
Co-reporter:Wenxi Guo;Xiaoyi Li;Mengxiao Chen;Lu Xu;Lin Dong;Xia Cao;Wei Tang;Jing Zhu;Caofeng Pan;Zhong Lin Wang
Advanced Functional Materials 2014 Volume 24( Issue 42) pp:6691-6699
Publication Date(Web):
DOI:10.1002/adfm.201401168
Metal corrosion is universal in the nature and the corrosion prevention for metals plays an important role everywhere in national economic development and daily life. Here a disk triboelectric nanogenerator (TENG) with segmental structures is introduced as power source to achieve a special cathodic protection effect for steels. The output transferred charges and short-circuit current density of the TENG achieve 1.41 mC/min and 10.1 mA/m2, respectively, when the rotating speed is 1000 revolutions per minute (rpm). The cathodic protection potential, Tafel polarization curves and electrochemical impedance spectra (EIS) measurements are measured to evaluate the corrosion protection effect for the 403 stainless steel (403SS). The cathodic protection potential range from –320 mV to –5320 mV is achieved by changing rotation speeds and external resistance when the steel is coupled in a 0.5 m NaCl solution to the negative pole of the disk TENG. The corrosion tests results indicate that the TENG can produce 59.1% degree of protection for Q235 steels in 0.5 m NaCl solution. Furthermore, an application of marine corrosion prevention is presented by mounting the TENG onto a buoy. This work demonstrates a versatile, cost-effect and self-powered system to scavenging mechanical energy from environment, leading to effectively protect the metal corrosion without additional power sources.
Co-reporter:Wenxi Guo, Chang Chen, Meidan Ye, Miaoqiang Lv and Changjian Lin
Nanoscale 2014 vol. 6(Issue 7) pp:3656-3663
Publication Date(Web):08 Jan 2014
DOI:10.1039/C3NR06295C
Recently, hybrid carbon materials and inorganic nanocrystals have received an intensive amount of attention and have opened up an exciting new field in the design and fabrication of high-performance catalysts. Here we present a novel kind of hybrid counter electrode (CE) consisting of a carbon fiber (CF) and Co9S8 nanotube arrays (NTs) for fiber-shaped flexible quantum dot-sensitized solar cells (QDSSCs). The growth mechanisms of Co(CO3)0.35Cl0.20(OH)1.10 nanowire arrays (NWs) on the CFs were discussed, and the catalytic activity of the CF, Pt and Co9S8/CF hybrid structure (Co9S8@CF) were elucidated systematically as well. An absolute energy conversion efficiency of 3.79% has been demonstrated under 100 mW cm−2 AM 1.5 illumination by using Co9S8@CF as a CE. This work not only demonstrates an innovative approach for growing cobalt sulfide NTs on flexible substrates that can be applied in flexible devices for energy harvesting and storage, but also provides a kind of hybrid structure and high-efficiency CE for QDSSCs.
Co-reporter:Meidan Ye, Dajiang Zheng, Mengye Wang, Chang Chen, Wenming Liao, Changjian Lin, and Zhiqun Lin
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 4) pp:2893
Publication Date(Web):January 27, 2014
DOI:10.1021/am405442n
Peachlike rutile TiO2 microsphere films were successfully produced on transparent conducting fluorine-doped tin oxide substrate via a facile, one-pot chemical bath route at low temperature (T = 80–85 °C) by introducing polyethylene glycol (PEG) as steric dispersant. The formation of TiO2 microspheres composed of nanoneedles was attributed to the acidic medium for the growth of 1D needle-shaped building blocks where the steric interaction of PEG reduced the aggregation of TiO2 nanoneedles and the Ostwald ripening process. Dye-sensitized solar cells (DSSCs) assembled by employing these complex rutile TiO2 microspheres as photoanodes exhibited a light-to-electricity conversion efficiency of 2.55%. It was further improved to a considerably high efficiency of 5.25% upon a series of post-treatments (i.e., calcination, TiCl4 treatment, and O2 plasma exposure) as a direct consequence of the well-crystallized TiO2 for fast electron transport, the enhanced capacity of dye loading, the effective light scattering, and trapping from microstructures.Keywords: chemical bath method; dye-sensitized solar cells; light-to-electricity conversion efficiency; low-temperature synthesis; post-treatments; rutile TiO2 microspheres;
Co-reporter:Miaoqiang Lv, Dajiang Zheng, Meidan Ye, Jing Xiao, Wenxi Guo, Yuekun Lai, Lan Sun, Changjian Lin and Juan Zuo
Energy & Environmental Science 2013 vol. 6(Issue 5) pp:1615-1622
Publication Date(Web):19 Mar 2013
DOI:10.1039/C3EE24125D
Highly ordered rutile TiO2 nanorod arrays (NRAs) are promising architectures in dye-sensitized solar cells (DSCs). However, the efficiency of DSCs based on such photoanodes is still relatively low, largely due to the limited internal surface area. Herein, we report that highly oriented rutile TiO2 NRAs with film thickness up to ∼30 μm was developed by a facile hydrothermal method. More importantly, an optimized porous rutile TiO2 NRAs with a large internal surface area was fabricated on the FTO (fluorine-doped tin oxide) substrate via a secondary hydrothermal treatment and when applied as the photoanodes in DSCs, a record efficiency of 7.91% was achieved.
Co-reporter:Mengye Wang, Lan Sun, Zhiqun Lin, Jianhuai Cai, Kunpeng Xie and Changjian Lin
Energy & Environmental Science 2013 vol. 6(Issue 4) pp:1211-1220
Publication Date(Web):25 Jan 2013
DOI:10.1039/C3EE24162A
Cu2O/TiO2 p–n heterojunction photoelectrodes were prepared by depositing different amounts of p-type Cu2O nanoparticles on n-type TiO2 nanotube arrays (i.e., forming Cu2O/TiO2 composite nanotubes) via an ultrasonication-assisted sequential chemical bath deposition. The success of deposition of Cu2O nanoparticles was corroborated by structural and composition characterizations. The enhanced absorption in the visible light region was observed in Cu2O/TiO2 composite nanotubes. The largely improved separation of photogenerated electrons and holes was revealed by photocurrent measurements. Consequently, Cu2O/TiO2 heterojunction photoelectrodes exhibited a more effective photoconversion capability than TiO2 nanotubes alone in photoelectrochemical measurements. Furthermore, Cu2O/TiO2 composite photoelectrodes also possessed superior photoelectrocatalytic activity and stability in the degradation of Rhodamine B. Intriguingly, by selecting an appropriate bias potential, a synergistic effect between electricity and visible light irradiation can be achieved.
Co-reporter:Meidan Ye;Dajiang Zheng;Miaoqiang Lv;Chang Chen;Zhiqun Lin
Advanced Materials 2013 Volume 25( Issue 22) pp:3039-3044
Publication Date(Web):
DOI:10.1002/adma.201205274
Co-reporter:Meidan Ye;Dajiang Zheng;Miaoqiang Lv;Chang Chen;Zhiqun Lin
Advanced Materials 2013 Volume 25( Issue 22) pp:
Publication Date(Web):
DOI:10.1002/adma.201370147
Co-reporter:Meidan Ye, Chang Chen, Miaoqiang Lv, Dajiang Zheng, Wenxi Guo and Changjian Lin
Nanoscale 2013 vol. 5(Issue 14) pp:6577-6583
Publication Date(Web):15 May 2013
DOI:10.1039/C3NR01604H
Three-dimensional (3D) crystalline anatase TiO2 hierarchical spheres were successfully derived from Ti foils via a fast, template-free, low-temperature hydrothermal route followed by a calcination post-treatment. These dandelion-like TiO2 spheres are composed of numerous ultrathin nanoribbons, which were subsequently split into fragile nanoflakes as a result of the decomposition of Ti-complex intermediates to TiO2 and H2O at high temperature. The dye-sensitized solar cells (DSSCs) employing such hierarchically structured TiO2 spheres as the photoanodes exhibited a light-to-electricity conversion efficiency of 8.50%, yielding a 28% enhancement in comparison with that (6.64%) of P25-based DSSCs, which mainly benefited from the enhanced capacity of dye loading in combination with effective light scattering and trapping from hierarchical architecture.
Co-reporter:Pinliang Jiang, Longxiang Lin, Fan Zhang, Xiang Dong, Lei Ren, Changjian Lin
Electrochimica Acta 2013 Volume 107() pp:16-25
Publication Date(Web):30 September 2013
DOI:10.1016/j.electacta.2013.05.120
•A hierarchical micro–nano spongelike TiO2 layer was constructed on Ti substrate.•The micro–nano TiO2 surface presented good corrosion resistance.•Excellent biomineration ability was observed on such micro–nano TiO2 layer.•Superior MG63 cell viability was discerned on the micro–nano structured surface.Surface structures of medical implants generally play a crucial role in tissue growth and healing while implanted into a living body. The surface design and modification of implants can effectively promote its biocompatibility and integration ability. In this study, a hierarchically superhydrophilic structure on titanium surface with a nano-spongelike titania layer on the micro-roughened titanium surface was constructed through dual acid etching and electrochemical treatments. It is shown that the structure of micro/nano-spongelike TiO2 provides not only better corrosion resistance and less oxygen vacancies, but also much higher ability of biomineralization after immersion in simulated body fluid (SBF) for 14 days. It is evident, by the cell culture for the different samples, that the micro–nano spongelike structured surface on Ti significantly promotes human osteoblast-like MG63 cell attachment and proliferation. All evaluations of electrochemical behavior and biological responses in this study indicate that the micro/nano-spongelike structure on Ti surface is of excellent chemical stability, bioactivity as well as biocompatibility for biomedical implant applications.
Co-reporter:Chen-Qing Ye, Rong-Gang Hu, Shi-Gang Dong, Xiao-Juan Zhang, Rui-Qing Hou, Rong-Gui Du, Chang-Jian Lin, Jin-Shan Pan
Journal of Electroanalytical Chemistry 2013 Volume 688() pp:275-281
Publication Date(Web):1 January 2013
DOI:10.1016/j.jelechem.2012.09.012
The corrosion behavior of reinforcement steel in simulated carbonated concrete pore (SCCP) solution containing different concentrations of chloride was studied by electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) measurements simultaneously, and the topographies of the steel specimens and the elemental distribution at corrosion area were examined by scanning electron microscope (SEM)/electron microprobe analysis (EMPA). The results showed the capacitive loop and polarization resistance decreased with chloride increasing. Furthermore, when the chloride concentration reached a critical value, the Bode plots obviously exhibited two phase angle peaks indicating two time constants. However, when the chloride content exceeded a critical value, the phase angle peaks decreased to one phenomenal peak. An equivalent circuit with two RC loops was used to characterize the corrosion behavior of reinforcement steel in SCCP solution according to the measurements of EIS. Based on the dependence of the equivalent circuit elements on chloride content and immersion time, the formation, growth and breakdown of passive film of the steel were discussed. It was found that the EIS evaluation of corrosion behavior for reinforcement steel in SCCP solution was good agreement with the LPR and SEM measurements. The EMPA mapping revealed MnS inclusions at steel surface play a leading role in the initiation of pitting corrosion.Highlights► The corrosion behavior of steel was studied continuously by EIS and LPR techniques. ► Bode plots contain more information concerning with the time constant for a reinforcement steel in SCCP solution. ► The phase angles increase and broaden with the improvement of passive film. ► 0.01 M can be defined as a critical Cl− value for steel corrosion in this solution. ► MnS inclusions at the steel surface play a leading role in pitting corrosion.
Co-reporter:Meidan Ye ; Jiaojiao Gong ; Yuekun Lai ; Changjian Lin ;Zhiqun Lin
Journal of the American Chemical Society 2012 Volume 134(Issue 38) pp:15720-15723
Publication Date(Web):September 10, 2012
DOI:10.1021/ja307449z
TiO2 nanotube arrays (TNTAs) sensitized by palladium quantum dots (Pd QDs) exhibit highly efficient photoelectrocatalytic hydrogen generation. Vertically oriented TNTAs were prepared by a three-step electrochemical anodization. Subsequently, Pd QDs with uniform size and narrow size distribution were formed on TiO2 nanotubes by a modified hydrothermal reaction (i.e., yielding nanocomposites of Pd QDs deposited on TNTAs, Pd@TNTAs). By exploiting Pd@TNTA nanocomposites as both photoanode and cathode, a substantially increased photon-to-current conversion efficiency of nearly 100% at λ = 330 nm and a greatly promoted photocatalytic hydrogen production rate of 592 μmol·h–1·cm–2 under 320 mW·cm–2 irradiation were achieved. The synergy between nanotubular structures of TiO2 and uniformly dispersed Pd QDs on TiO2 facilitated the charge transfer of photoinduced electrons from TiO2 nanotubes to Pd QDs and the high activity of Pd QDs catalytic center, thereby leading to high-efficiency photoelectrocatalytic hydrogen generation.
Co-reporter:Wenxi Guo ; Chen Xu ; Xue Wang ; Sihong Wang ; Caofeng Pan ; Changjian Lin ;Zhong Lin Wang
Journal of the American Chemical Society 2012 Volume 134(Issue 9) pp:4437-4441
Publication Date(Web):February 2, 2012
DOI:10.1021/ja2120585
Because of their special application in photovoltaics, the growth of one-dimensional single-crystalline TiO2 nanostructures on a flexible substrate is receiving intensive attention. Here we present a study of rectangular bunched TiO2 nanorod (NR) arrays grown on carbon fibers (CFs) from titanium by a “dissolve and grow” method. After a corrosion process in a strong acid solution, every single nanorod is etched into a number of small nanowires. Tube-shaped dye-sensitized solar cells are fabricated by using etched TiO2 NRs-coated CFs as the photoanode. An absolute energy conversion efficiency of 1.28% has been demonstrated under 100 mW cm–2 AM 1.5 illumination. This work demonstrates an innovative method for growing bunched TiO2 NRs on flexible substrates that can be applied in flexible devices for energy harvesting and storage.
Co-reporter:Miaoqiang Lv, Dajiang Zheng, Meidan Ye, Lan Sun, Jing Xiao, Wenxi Guo and Changjian Lin
Nanoscale 2012 vol. 4(Issue 19) pp:5872-5879
Publication Date(Web):30 Jul 2012
DOI:10.1039/C2NR31431B
One-dimensional (1-D) TiO2 nanorod arrays (NRAs) with large inner surface area are desired in dye-sensitized solar cells (DSSCs). So far, good performance of DSSCs based on 1-D rutile TiO2 NRAs remains a challenge mainly owing to their low dye-loading ability resulting from the insufficient specific surface area of 1-D TiO2 nanostructures. In this paper, densely aligned TiO2 NRAs with tunable thickness were grown directly on transparent conductive fluorine-doped tin oxide (FTO) substrates by hydrothermal method, followed by a facile chemical etching route to further increase the specific surface area of the TiO2 NRAs. The etching treatment leads to the split of TiO2 nanorods into secondary nanorods with a reduced diameter, which markedly enlarges the inner surface area of the TiO2 NRAs. The formation of 1-D rutile TiO2 nanotube arrays (NTAs) is observed as well in the etched TiO2 films. Finally, a DSSC efficiency of 5.94% was achieved by utilizing an etched TiO2 NRA as the photoanode, which is so far the best DSSC efficiency that has been reported for the 1-D rutile TiO2 NRA films.
Co-reporter:Chen-Qing Ye, Rong-Gang Hu, Yan Li, Chang-Jian Lin, Jin-Shan Pan
Corrosion Science 2012 Volume 61() pp:242-245
Publication Date(Web):August 2012
DOI:10.1016/j.corsci.2012.04.020
Based on a home-built integrated system of scanning reference electrode technique and scanning tunneling microscope (SRET/STM), a method for in situ measurement of vertical potential in the thin layer of solution closed to electrode surface during localized corrosion of stainless steel has been successfully established in this work. An obviously different vertical profile of potential over corrosion active sites and passive sites were firstly observed. The reason for this different was discussed taking into account the distribution of electric field and concentration of Fe3+/Fe2+ in a thin layer solution closed to electrode surface, due to the occurrence of localized corrosion.Highlights► We develop a method for measuring vertical potential by combining SRET with STM. ► At corrosion active sites, the vertical potential profile exhibits a V-shape. ► At the passive area, the vertical potential profile decreases monotonously. ► The species distribution at corrosion active is different from at passive areas.
Co-reporter:Fan Zhang, Long-Xiang Lin, Guo-Wei Wang, Ren Hu, Chang-Jian Lin, Yong Chen
Electrochimica Acta 2012 Volume 85() pp:152-161
Publication Date(Web):15 December 2012
DOI:10.1016/j.electacta.2012.08.033
This paper reports a transparent Ti microelectrode array (MEA) system for a high-throughput evaluation of bioresponsibility using electrochemical impedance spectroscopy (EIS). The MEA chip integrated with hydroxyapatite (HA) and Ag coatings was selectively prepared by electrochemical deposition based on a novel procedure of multichannel current control. The EIS measurement of living MG63 osteosarcoma cells in the integrated MEA chip was conducted, and the result was analyzed using an equivalent circuit corresponding to a titanium oxide film, protein adsorption layer, cell adhesion layer, and medium. It is shown that the bioresponsibility of Ti–Ag–HA on the MEA chip can be improved, compared with the Ti, Ti–HA, and Ti–Ag coatings. The system was further used for real-time EIS monitoring during continuous cell culture for a long period (12 days). The effect of the long-term cell proliferation on the EIS behavior was discussed. This integrated system is valuable to significantly simplify the operation procedures and quickly evaluate the bioresponsibility of biomaterials.Graphical abstractHighlights► The EIS of living MG63 cells on the Ti MEA chip with Ag, HA, and Ag–HA was monitored. ► The Rcell can be related to the bioresponsibility of the coatings. ► The bioactivity order was evaluated as follows: Ti–Ag–HA > Ti–HA ≈ Ti–Ag > Ti.
Co-reporter:Dajiang Zheng, Miaoqiang Lv, Shiping Wang, Wenxi Guo, Lan Sun, Changjian Lin
Electrochimica Acta 2012 Volume 83() pp:155-159
Publication Date(Web):30 November 2012
DOI:10.1016/j.electacta.2012.07.114
A novel combined structure with a mixture of TiO2 nanotubes and nanoparticles was fabricated by anodization of Ti, followed by a controlled annealing post-treatment. The TiO2 nanoparticles with the average diameter of 40 nm were uniformly dispersed on the surface of TiO2 nanotubes with the diameter of 110–130 nm and the length of 15 μm. The photoelectric behavior of the as-prepared photoanode in dye-sensitized solar cells was analyzed by the measurements of I–V and EIS. It was found that the energy conversion efficiency of the solar cell with composite photoanode was 5.75%, enhanced up to 25.8% compared to that of the photoanode of pure TiO2 nanotube structure in the same condition.Graphical abstractHighlights►A new combined TiO2 structure with nanotubes and nanoparticles was developed. ► It was prepared by an anodizing and sealed annealing process. ► This structure obviously increased the dye loading and liquid circulation. ►This structure maintains a good property with less interface recombination via EIS analysis. ► This structure clearly enhanced the conversion efficiency of DSSC.
Co-reporter:Yuekun Lai, Zequan Lin, Dajiang Zheng, Lifeng Chi, Ronggui Du, Changjian Lin
Electrochimica Acta 2012 Volume 79() pp:175-181
Publication Date(Web):30 September 2012
DOI:10.1016/j.electacta.2012.06.105
In this work, we designed and fabricated a novel one-dimensional CdSe/CdS@TiO2 core–shell nanotube array for quantum dots co-sensitized solar cells (QDSSCs) application. The three-component core–shell nanotube array structure was formed cascade by coating CdS nanoparticles with a successive ionic layer adsorption and reaction process and a thin CdSe layer by chemical bath deposition onto the vertical TiO2 nanotube arrays (TNAs), which enhanced the optical absorption in the visible region and presented an stepwise band-edge level structure to improve the charge separation. Under optimum conditions, the CdS/CdSe co-sensitized QDSSC demonstrated a power conversion efficiency (PCE) of 2.40% under 100 mW/cm2 illumination of simulate sunlight. Furthermore, an improved QDSSC with a PCE up to 2.74% was obtained by sealed annealing of TNAs, due to the transformation of thin and smooth nanotube to thick and rough particle nanotube.Graphical abstractHighlights► Uniform CdS nanoparticles on TiO2 nanotube arrays (TNAs) are obtained. ► A thin CdSe shell onto the CdS@TNAs is fabricated by chemical bath deposition (CBD). ► An one-dimension CdSe/CdS quantum dots co-sensitized TNAs solar cell is constructed. ► The effect of CdSe content on power conversion efficiency (PCE) is investigated. ► An improved QDSSC (PCE = 2.74%) is achieved by sealed annealing of TNAs.
Co-reporter:Junren Lin, Changjian Lin, Zhongyu Lin, Yan Zhao, Ronggui Du
Cement and Concrete Research 2012 Volume 42(Issue 1) pp:95-98
Publication Date(Web):January 2012
DOI:10.1016/j.cemconres.2011.08.007
Fourier Transform Infrared Spectroscopy with Multiple Internal Reflection mode (FTIR-MIR) has been applied for the first time to in situ follow the transport process of corrosive species through a mortar layer and their accumulation at the internal reflection element (IRE)/mortar interface. The kinetic processes of H2O and SO42− transport through the mortar specimens with different curing time were studied. The results indicated that H2O and SO42− presented different transport behavior through the mortar layer. Adding Na2SO4 into distilled water resulted in a slower transport rate of H2O. And the curing time of mortar had a significant effect on its permeability. The in situ FTIR-MIR measurement was proved to be able to provide reliable information on the interface and the transport process through mortar.
Co-reporter:Rong-Gang Hu, Su Zhang, Jun-Fu Bu, Chang-Jian Lin, Guang-Ling Song
Progress in Organic Coatings 2012 Volume 73(2–3) pp:129-141
Publication Date(Web):February–March 2012
DOI:10.1016/j.porgcoat.2011.10.011
The excellent properties of magnesium alloys, especially the high strength/weight ratio, make them desirable materials in the automotive industry. However, their high corrosion susceptibility has greatly limited or even prevented their larger scale use for various applications. Organic coating is one of the most effective ways to prevent magnesium alloys from corrosion. In this report, the recent progress of organic coatings on magnesium alloys and techniques for evaluating the performance of organic coatings are reviewed.As a critical layer in a normal coating system, organic coating has great potential to prevent magnesium alloys from corrosion attack. However, some unsolved problems currently limit the application of organic coatings. Firstly, organic coatings usually have poor adhesion if they are applied without an appropriate pre-treatment. Sol–gel coating or plasma polymerization requires the least pre-treatment prior to deposition. However, the corrosion and wear resistance of these coatings have not been documented. Secondly, it is difficult to prepare a uniform, pore-free organic layer. So, it is usually necessary to apply multiple layers of these coatings to provide sufficient/optimum corrosion and wear resistance. Finally, a number of organic coating techniques are still solvent based, which poses an environmental concern. New water-borne and powder coating technologies should be developed.In order to evaluate the performance of organic coatings on magnesium, both electrochemical and non-electrochemical techniques have been developed. Information from different techniques gives insight into the organic coating/magnesium alloy interface in different aspects. Comprehensive knowledge about the interface is indispensible for understanding the degradation of the organic coating and developing new coating strategies.Highlights▸ Organic coatings have great potential to prevent Mg alloys from corrosion attack. ▸ Organic coatings have poor adhesion if applied without appropriate pre-treatment. ▸ New water-borne and powder coating technologies are highly demanded. ▸ Electrochemical + non-electrochemical techniques provide insight into coatings.
Co-reporter:Yuekun Lai, Jiaojiao Gong, Changjian Lin
International Journal of Hydrogen Energy 2012 Volume 37(Issue 8) pp:6438-6446
Publication Date(Web):April 2012
DOI:10.1016/j.ijhydene.2012.01.078
Highly efficient water splitting electrode based on uniform platinum (Pt) nanoparticles on self-organized TiO2 nanotube arrays (TNTAs) was prepared by a combination of multi-step electrochemical anodization with facile photoreduction process. Uniform platinum (Pt) nanoparticles with an average diameter of 8 nm are distributed homogeneously on nanoporous top layer and underneath TiO2 nanotube wall. In comparison to pristine TNTAs, Pt@TNTAs show substantially enhanced photocurrent density and the incident photon-to-current conversion efficiency (IPCE) in the entire wavelength window. The maximum photocurrent density and IPCE from the optimized Pt@TNTAs photoelectrode (Pt, ～1.57 wt%) were about 24.2 mA cm−2 and 87.9% at 350 nm, which is much higher than that of the pure nanotubes sample (16.3 mA cm−2 and 67.3%). The resultant Pt@TNTAs architecture exhibited significantly enhanced photoelectrochemical activities for solar water splitting with hydrogen evolution rate up to 495 μmol h−1 cm−2 in 2 M Na2CO3 + 0.5 M ethylene glycol under the optimal external bias of −0.3 VSCE.Highlights► Sub-10 nanometer Pt particles are prepared by a simple photo-reduction method. ► The effect of multi-step process and anodizing voltage are investigated. ► The hydrogen production rate are increased by decorating Pt nanoparticles. ► Organic additive enables enhance hydrogen production. ► Pt@TNTAs electrode is stable and promising for hydrogen generation.
Co-reporter:ShiGang Dong, Bing Zhao, ChangJian Lin, RongGui Du, RongGang Hu, Gregory Xiaoge Zhang
Construction and Building Materials 2012 Volume 28(Issue 1) pp:72-78
Publication Date(Web):March 2012
DOI:10.1016/j.conbuildmat.2011.08.026
The corrosion behavior of epoxy/zinc duplex coated rebar embedded in concrete is evaluated comparing with the black steel, galvanized and epoxy coated rebars for a long term in ocean environment. The effect of mechanical damages of epoxy coatings on the corrosion protection is examined. The epoxy coated and epoxy/zinc duplex coated rebars show the higher anti-corrosion performance than other types of rebars. However, once the epoxy coating is mechanically damaged, the more serious corrosion may occur in the damaged area of epoxy coated rebar in concrete. The epoxy/zinc duplex coating remains a good corrosion protection to steel in concrete even when suffering from some mechanical damages.Highlights► The corrosion of epoxy/zinc duplex coated rebar is examined in the sea environment. ► The effect of coating damages on corrosion behavior is also studied. ► The epoxy coating has good protection to steel, but largely effected by the damages. ► The duplex coating remains good protection and is less effected by the damages.
Co-reporter:Wenxi Guo, Chen Xu, Guang Zhu, Caofeng Pan, Changjian Lin, Zhong Lin Wang
Nano Energy 2012 Volume 1(Issue 1) pp:176-182
Publication Date(Web):January 2012
DOI:10.1016/j.nanoen.2011.09.003
We have developed an innovative structure for enhancing the performance of the fiber based 3D DSSC by integrating optical-fiber/TiO2-nanowire-arrays hybrid structures with cylindrical counterelectrodes. The TiO2 nanowire arrays are grown on the optical fiber using liquid phase deposition method and platinum is coated on the inwall of stainless steel capillary tubes using electroless deposition. The 3D DSSC is made by sheathering the tube on the fiber structure. In comparison to planar illumination geometry, the efficiency for the 3D structure has been enhanced by a factor of 3.6. An absolute efficiency of 6% has been demonstrated at an optimal length of TiO2 NWs (12 μm). This study demonstrates a new methodology for building flexible and high-efficient fiber based 3D solar cells that can be expanded to concentrating solar cells.Graphical AbstractHighlights► A 3D structural DSSC based on TiO2 NWs and Tubular Counterelectrode is designed; about 6% full sun efficiency has been achieved using this configuration. ► TiO2 NWs are successfully grown on the optical fiber and the optimization length of TiO2 NWs in the application of 3D DSSCs is discussed. ► Uniform and density platinum layer is successfully deposoted on the inwall of stainless steel capillary tube.
Co-reporter:Meidan Ye, Xukai Xin, Changjian Lin, and Zhiqun Lin
Nano Letters 2011 Volume 11(Issue 8) pp:3214-3220
Publication Date(Web):July 5, 2011
DOI:10.1021/nl2014845
Dye-sensitized solar cells (DSSCs) based on hierarchically structured TiO2 nanotubes prepared by a facile combination of two-step electrochemical anodization with a hydrothermal process exhibited remarkable performance. Vertically oriented, smooth TiO2 nanotube arrays fabricated by a two-step anodic oxidation were subjected to hydrothermal treatment, thereby creating advantageous roughness on the TiO2 nanotube surface (i.e., forming hierarchically structured nanotube arrays—nanoscopic tubes composed of a large number of nanoparticles on the surface) that led to an increased dye loading. Subsequently, these nanotubes were exploited to produce DSSCs in a backside illumination mode, yielding a significantly high power conversion efficiency, of 7.12%, which was further increased to 7.75% upon exposure to O2 plasma.
Co-reporter:Jiaojiao Gong, Changjian Lin, Meidan Ye and Yuekun Lai
Chemical Communications 2011 vol. 47(Issue 9) pp:2598-2600
Publication Date(Web):20 Dec 2010
DOI:10.1039/C0CC04407E
A novel nanocomposite TiO2 film consisting of a bamboo leaf-like nano TiO2 layer on a nanotubular TiO2 arrays surface is synthesized by electrochemical anodization with wet chemical pretreatment; it shows almost three times higher activity as compared to that of nanotubular TiO2 arrays alone.
Co-reporter:Kunpeng Xie, Qi Wu, Yingying Wang, Wenxi Guo, Mengye Wang, Lan Sun, Changjian Lin
Electrochemistry Communications 2011 Volume 13(Issue 12) pp:1469-1472
Publication Date(Web):December 2011
DOI:10.1016/j.elecom.2011.09.023
The Z-scheme type CdS–Ag–TiO2 nanotube arrays were constructed by electrochemical methods. The self-organized highly oriented TiO2 nanotube arrays (TiO2NTs) were first prepared by anodizing Ti sheet. Subsequently, the Ag–CdS nanoparticles composed of Ag core and CdS shell were electrodeposited on the TiO2NTs. In the prepared three-component system, the Ag–CdS core–shell nanoparticles were well dispersed on the surface of anatase TiO2 nanotubes. This three-component system exhibited enhanced photoelectrochemical and photocatalytic activities, far exceeding those of the single- and two-component systems.Highlights► Z-scheme type CdS–Ag–TiO2 nanotube arrays are constructed by electrochemical method. ► Ag–CdS core–shell nanoparticles are well dispersed on anatase TiO2 nanotubes. ► The CdS–Ag–TiO2 system exhibits significantly enhanced photocatalytic activity.
Co-reporter:Jing Li, Chang-Jian Lin, Jun-Tao Li, Ze-Quan Lin
Thin Solid Films 2011 Volume 519(Issue 16) pp:5494-5502
Publication Date(Web):1 June 2011
DOI:10.1016/j.tsf.2011.03.116
An electrodeposited CdS nanoparticles-modified highly-ordered TiO2 nanotube arrays (CdS–TNs) photoelectrode and its performance of photocathodic protection are reported. The self-organized TiO2 nanotube arrays are fabricated by electrochemical anodization in an organic–inorganic mixed electrolyte and sensitized with CdS nanoparticles by electrodeposition via a single-step direct current. The morphology, crystalline phase, and composition of the CdS–TNs films were characterized systematically by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and ultraviolet–visible (UV–Vis) spectroscopy, respectively. The photoelectrochemical performances of the CdS–TNs film under illumination and dark conditions in 0.5 M NaCl solution were evaluated through the electrochemical measurements. It is indicated that the TNs incorporated by CdS effectively harvest solar light in the UV as well as the visible light (up to 480 nm) region. It is supposed that the high photoelectro-response activity of the CdS–TNs is attributed to the increased efficiency of charge separation and transport of electrons. The electrode potentials of 304 stainless steel coupled with the CdS–TNs is found to be negatively shifted for about 246 mV and 215 mV under UV and white light irradiation, respectively, which can be remained for 24 h even in darkness. It is implied that the CdS–TNs are able to effectively function a photogenerated cathodic protection for metals both under the UV and visible light illumination.
Co-reporter:JunFu Bu;Lan Sun;Qi Wu;MengYe Wang
Science China Chemistry 2011 Volume 54( Issue 10) pp:
Publication Date(Web):2011 October
DOI:10.1007/s11426-011-4377-9
Ti species have been deposited on low-voltage etched aluminum foils by a simple electrochemical method using a Ti anode as Ti source in a Ti-free I2-dissolved acetone solution. After annealing at 500–600 °C in air, an Al2O3-TiO2 composite oxide film was formed on the surface of the etched aluminum foil by anodizing galvanostatically in an ammonium adipate solution. The effects of I2 concentration in the acetone solution, applied anode voltage, electrolysis time, and annealing temperature on the specific capacitance of the aluminum anode foils were investigated. The TiO2-deposited specimens prepared by applying a potential of 50 V for 3 min in 2.5 mM I2-added acetone solution followed by annealing at 550 °C after anodization exhibited the highest specific capacitance, with an enhancement of 22% compared with pure etched aluminum foil specimens. The electrodeposition process and the change of the anode voltage during the anodization were analyzed.
Co-reporter:Kunpeng Xie, Lan Sun, Chenglin Wang, Yuekun Lai, Mengye Wang, Hongbo Chen, Changjian Lin
Electrochimica Acta 2010 Volume 55(Issue 24) pp:7211-7218
Publication Date(Web):1 October 2010
DOI:10.1016/j.electacta.2010.07.030
A pulse current deposition technique was adopted to construct highly dispersed Ag nanoparticles on TiO2 nanotube arrays which were prepared by the electrochemical anodization. The morphology, crystallinity, elemental composition, and UV–vis absorption of Ag/TiO2 nanotube arrays were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). In particular, the photoelectrochemical properties and photoelectrocatalytic activity under UV light irradiation and the photocatalytic activity under visible light irradiation for newly synthesized Ag/TiO2 nanotube arrays were investigated. The maximum incident photon to charge carrier efficiency (IPCE) value of Ag/TiO2 nanotube arrays was 51%, much higher than that of pure TiO2 nanotube arrays. Ag/TiO2 nanotube arrays exhibited higher photocatalytic activities than the pure TiO2 nanotube arrays under both UV and visible light irradiation. The photoelectrocatalytic activity of Ag/TiO2 nanotube arrays under UV light irradiation was 1.6-fold enhancement compared with pure TiO2 nanotube arrays. This approach can be used in synthesizing various metal-loaded nanotube arrays materials.
Co-reporter:Yuekun Lai, Zequan Lin, Jianying Huang, Lan Sun, Zhong Chen and Changjian Lin
New Journal of Chemistry 2010 vol. 34(Issue 1) pp:44-51
Publication Date(Web):17 Sep 2009
DOI:10.1039/B9NJ00325H
Position- and orientation-controllable micropatterned ZnO/TiO2 nanostructures with different morphologies have been fabricated using a novel and versatile superhydrophilic/superhydrophobic template. Scanning electron microscopy, optical microscopy, electron probe microanalysis and X-ray diffraction were systematically used to confirm the successful fabrication of the patterns and to characterize the structure and morphology. The selective growth of ordered ZnO nanostructured patterns on the TiO2 nanotube surface employs a simple photocatalytic lithography technique with mild reaction conditions and in the absence of seeds and noble metal catalysts. The photoelectrical properties of the micropatterned ZnO/TiO2 nanocomposites with unique heterojunction structure and different density and orientation of the ZnO crystals were also investigated. It is expected that this novel micropatterned technique based on the superhydrophilic/superhydrophobic template will become a powerful tool for fabricating various types of micropatterned nanomaterials and devices.
Co-reporter:Yuekun Lai, Zequan Lin, Zhong Chen, Jianying Huang, Changjian Lin
Materials Letters 2010 Volume 64(Issue 11) pp:1309-1312
Publication Date(Web):15 June 2010
DOI:10.1016/j.matlet.2010.03.017
A wettability template-assisted process was applied to selectively deposit cadmium sulfide (CdS) nanospheres on TiO2 nanotube layers to form uniformly coupled CdS/TiO2 semiconductor heterojunction micropatterns. The effect of deposition time on the size and morphology of the as-prepared CdS/TiO2 array patterns was investigated. It is shown that the CdS nanocrystals with a highly ordered, hierarchically porous structure in nano-micro dual scales could be selectively grown within the superhydrophilic regions. The patterned CdS/TiO2 heterojunctions have demonstrated enhanced photo-response under both UV and visible light irradiation. This novel template patterning technique, which is based on wettability contrast, can be applied to a broad range of technological areas, such as sensor arrays and optoelectronic devices.
Co-reporter:Ren Hu, Changjian Lin, Hui Wang, Tao Tao
Materials Letters 2010 Volume 64(Issue 8) pp:915-917
Publication Date(Web):30 April 2010
DOI:10.1016/j.matlet.2010.01.057
In this work, collagen І was introduced as an additive to the dilute electrolyte used for direct electrochemical deposition of hydroxyapatite (HA) coating, and its modulation effects on the morphology and crystal structure of the HA coating were examined by SEM and XRD, respectively. Collagen I-modified HA coating was found to exhibit a micro-porous structure, formed by the ordered arrangements of ultra-fine HA crystals. The crystal structure of the modified HA coating was demonstrated to be similar to that of the natural bone. Further compositional studies using FTIR spectroscopy supported the integration of the collagen into the HA coating.
Co-reporter:Yuekun Lai, Yongxia Huang, Hui Wang, Jianying Huang, Zhong Chen, Changjian Lin
Colloids and Surfaces B: Biointerfaces 2010 Volume 76(Issue 1) pp:117-122
Publication Date(Web):1 March 2010
DOI:10.1016/j.colsurfb.2009.10.023
Using a patterned superhydrophobicity/superhydrophilicity template, micropatterned octacalcium phosphate (OCP) has been successfully fabricated on TiO2 nanotube array surface. The resultant OCP micropattern has been characterized with scanning electron microscopy, optical microscopy, X-ray diffraction and electron probe microanalyzer. It is shown that the ribbon-like OCP crystals possess a highly ordered and hierarchically porous structure at nano–micro-scales. They can be selectively grown at superhydrophilic areas which are confined by the hydrophobic regions. The high wetting contrast template proves to be useful for constructing well-defined dual scale OCP film with porous structure biomimic to natural bone. A mechanism has been proposed to explain the formation of the OCP patterned film with hierarchically porous structure and distinct selectivity.
Co-reporter:Jing Li, Chang-Jian Lin, Yue-Kun Lai, Rong-Gui Du
Surface and Coatings Technology 2010 205(2) pp: 557-564
Publication Date(Web):
DOI:10.1016/j.surfcoat.2010.07.030
Co-reporter:LanQiang Li;ShiGang Dong;Wei Wang;RongGang Hu
Science China Technological Sciences 2010 Volume 53( Issue 5) pp:1285-1289
Publication Date(Web):2010 May
DOI:10.1007/s11431-010-0152-y
An array electrode technique was developed as a novel electrochemical method for studying the interaction between macrocell and microcell in the early corrosion process of reinforcing steel in cement mortar. The corrosion potential and galvanic current of macrocell corrosion of the reinforcing steel in cement mortar were imaged by the array electrode technique during the corrosion initiation and propagation. It was certified that the corrosion macrocell current is closely related with the difference of corrosion potential between the anodic and cathodic areas. The corrosion macrocell and microcell always exist during the corrosion process. The interaction of corrosion macrocell and corrosion microcell of steel in concrete was directly sensed by the array electrode for the first time, and was discussed in terms of corrosion electrochemistry.
Co-reporter:Yun Yang, Yuekun Lai, Qiqing Zhang, Ke Wu, Lihai Zhang, Changjian Lin, Peifu Tang
Colloids and Surfaces B: Biointerfaces 2010 Volume 79(Issue 1) pp:309-313
Publication Date(Web):1 August 2010
DOI:10.1016/j.colsurfb.2010.04.013
A controllable fabrication of superhydrophobic surface on titanium biomedical implants was successfully developed to improve the blood compatibility and anti-coagulation performance of biomedical implants. The electrochemical anodization was employed to form a layer of TiO2 nanotubes on the titanium substrate, and then a hydrophobic monolayer was self-assembled on the nanotube surface. The morphology and wettability of the nanotube arrays were investigated by scanning electron microcopy and water drop contact angle measurement, respectively. From the in vitro blood compatibility evaluation, it was observed that not only very few of platelets were attached onto the superhydrophobic surface, but also the attached platelets were not activated in this condition. Comparatively, a large number of platelets adhered and spread out on both the bare titanium substrate and the superhydrophilic surface which was obtained by exposing the TiO2 nanotubes under a UV irradiation. The results indicated that the superhydrophobic TiO2 nanotube layers exhibited excellent blood compatibility and remarkable performance in preventing platelets from adhering to the implant surface. Therefore, the construction of superhydrophobic surface on biomedical implants could pave a way to improve the blood compatibility of the biomedical devices and implants.
Co-reporter:Yuekun Lai, Yicong Chen, Yuxin Tang, Dangguo Gong, Zhong Chen, Changjian Lin
Electrochemistry Communications 2009 Volume 11(Issue 12) pp:2268-2271
Publication Date(Web):December 2009
DOI:10.1016/j.elecom.2009.10.004
A facile electrophoretic deposition (EPD) process has been developed to prepare thin films consisting of titanate nanotubes (TNTs) that were synthesized by a hydrothermal approach. Such an EPD process offers easy control in the film thickness and the adhesion to the substrate was found to be strong. The chemical composition and structure of the products have been characterized by XRD, HRTEM, and FESEM. It was found that the functionalization of TNTs plays a key role on the electrolyte stability and the formation of a uniform TNT film with good adhesion. The as-prepared TNT films show exceptional superhydrophilic behavior with ultra-fast spreading, while it converts to superhydrophobicity yet with strong adhesion after 1H,1H,2H,2H-perfluorooctyl-triethoxysilane modification. This study provides an interesting method to prepare films with extremely high wettability contrast that are useful for producing different types of functional materials.
Co-reporter:Yan Li, Ronggang Hu, Jingrun Wang, Yongxia Huang, Chang-Jian Lin
Electrochimica Acta 2009 Volume 54(Issue 27) pp:7134-7140
Publication Date(Web):30 November 2009
DOI:10.1016/j.electacta.2009.07.042
An in-situ atomic force microscope (AFM), optical microscope and electrochemical noise (ECN) techniques were applied to the investigation of corrosion initiations in an early stage of 1Cr18Ni9Ti stainless steel immersed in 0.5 M HCl solution. The electrochemical current noise data has been analyzed using discrete wavelet transform (DWT). For the first time, the origin of wavelet coefficients is discussed based on the correlation between the evolution of the energy distribution plot (EDP) of wavelet coefficients and topographic changes. It is found that the occurrence of initiation of metastable pitting at susceptive sites is resulted from the reductive breakdown of passive film of stainless steel in the diluted HCL solution. The coefficients d4–d6 are originated from metastable pitting, d7 represents the formation and growth of stable pitting while d8 corresponds to the general corrosion.
Co-reporter:Yuekun Lai, Huifang Zhuang, Lan Sun, Zhong Chen, Changjian Lin
Electrochimica Acta 2009 Volume 54(Issue 26) pp:6536-6542
Publication Date(Web):1 November 2009
DOI:10.1016/j.electacta.2009.06.029
The formation of self-organized TiO2 nanotube array films by electrochemical anodizing titanium foils was investigated in a developed organic–inorganic mixed electrolyte. It was found that the structure and morphology of the TiO2 nanotube layer were greatly dependent upon the electrolyte composition, anodizing potential and time. Under the optimized electrolyte composition and electrochemical conditions, a controllable, well-ordered TiO2 nanotube array layer could be fabricated in a short time. The diameters of the as-prepared TiO2 nanotubes could be adjusted from 20 to 150 nm, and the thickness could be adjusted from a few hundred nanometers to several micrometers. The photoresponse and the photocatalytic activity of the highly ordered TiO2 nanotube array films were also examined. The nanotube array film with a thickness of about 2.5 μm had the highest incident photon to photocurrent conversion efficiency (IPCE) (34.3%) at the 350 nm wavelength, and had better charge transfer ability under UV light illumination. The photocatalytic experimental results indicated that the 450 °C annealing samples have the highest photodegradation efficiency for methyl orange pollutant.
Co-reporter:Fan Zhang, Jinshan Pan, Changjian Lin
Corrosion Science 2009 Volume 51(Issue 9) pp:2130-2138
Publication Date(Web):September 2009
DOI:10.1016/j.corsci.2009.05.044
The correlation of localized corrosion behavior and microstructure of reinforcement steel in simulated concrete pore solutions was investigated. The SEM/EDS analysis showed that most of ferrite, minor amount of pearlite and some MnS inclusions existed on the steel surface. The SKPFM results indicated a higher corrosion tendency at the ferrite grain boundaries, pearlite grains and MnS inclusions. The EIS and electrochemical polarization measurements demonstrated the influence of pH and chloride concentration on the corrosion behavior. In situ optical observations and AFM images revealed a detail of the localized corrosion behavior, which was in good agreement with the results from the other measurements.
Co-reporter:L. Sun, J. Li, C.L. Wang, S.F. Li, H.B. Chen, C.J. Lin
Solar Energy Materials and Solar Cells 2009 93(10) pp: 1875-1880
Publication Date(Web):
DOI:10.1016/j.solmat.2009.07.001
Co-reporter:Ren Hu, Changjian Lin, Haiyan Shi, Hui Wang
Materials Chemistry and Physics 2009 115(2–3) pp: 718-723
Publication Date(Web):
DOI:10.1016/j.matchemphys.2009.02.022
Co-reporter:Yuekun Lai, Changjian Lin, Hui Wang, Jianying Huang, Huifang Zhuang, Lan Sun
Electrochemistry Communications 2008 Volume 10(Issue 3) pp:387-391
Publication Date(Web):March 2008
DOI:10.1016/j.elecom.2007.12.020
The present paper describes an unconventional approach to fabricate the superhydrophilic–superhydrophobic micropatterns on the TiO2 nanotube structured film by photocatalytic lithography with a two-step process. At the first step, the superhydrophobic TiO2 nanotube film is fabricated through electrochemical and self-assembled techniques. And at the second step, the superhydrophobic film is selectively exposed to UV light through a photomask to locally photocatalyse the organic monolayer assembled on the TiO2 nanotube surface. The superhydrophilic–superhydrophobic micropatterns have thus been developed, as a novel template to fabricate a define micropatterned coating of nano octacalcium phosphate by electrochemical deposition. It is indicated that these combined processes reveal a very promising approach for constructing well-defined micropatterns of various functional materials.
Co-reporter:Hui Wang;Chang-Jian Lin;Ren Hu;Fan Zhang;Li-Wen Lin
Journal of Biomedical Materials Research Part A 2008 Volume 87A( Issue 3) pp:698-705
Publication Date(Web):
DOI:10.1002/jbm.a.31653
Abstract
In this study, a novel nano-micro structured octacalcium phosphate/protein (OCP/protein) composite coating has been successfully constructed on titanium substrate by using an electrochemically induced deposition technique. The structure and composition of the composite coating were investigated by XRD, XPS, SEM and FTIR. It is shown that the composite coating consists of OCP and protein with a highly ordered and hierarchically porous structure in nano-micro scale, similar to the naturalbone structure. The nanoindentation experiment proves a good mechanical property for the OCP/protein composite coating on titanium substrate. In the osteoblast cell culture in vitro, the cell adhesion for the OCP/protein composite coating is observed to be greatly improved. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Co-reporter:Yuekun Lai, Yicong Chen, Huifang Zhuang, Changjian Lin
Materials Letters 2008 Volume 62(21–22) pp:3688-3690
Publication Date(Web):15 August 2008
DOI:10.1016/j.matlet.2008.04.055
A facile sol–gel and hydrothermal process has been developed to prepare the Ag nanoparticles supported TiO2 nanostructures. The chemical composition and structure of the products have been characterized systematically with XRD, HRTEM and XPS spectrum. The results indicate that Ag species nanoparticles dispersed uniformly on the TiO2 nanostructured surface are of metallic nature. A possible mechanism has been proposed to explain the formation of silver nanoparticles on TiO2 nanostructures with high dispersion.
Co-reporter:Changjian Lin;Huijuan Han;Fang Zhang
Journal of Materials Science: Materials in Medicine 2008 Volume 19( Issue 7) pp:2569-2574
Publication Date(Web):2008 July
DOI:10.1007/s10856-007-3196-1
A composite coating of hydroxyapatite (HA)/multi-walled carbon nanotubes (MWNTs) has been fabricated by electrophoretic deposition (EPD). The nano powders of HA and MWNTs were dispersed in ethanol with total concentration of 0.005 g/mL and MWNTs 20% and 30% contents (wt). And the pH value of suspension was adjusted in a range from 4 to 5. After stabilization the mixture was ultrasonically treated for 3 h to form a stable suspension. Prior to the electrophoretic deposition, the titanium substrate was hydrothermally treated at 140 in NaOH (10 mol/L) solution for 6 h. A titanium sheet and circinal net of stainless steel were used as a cathode and an anode respectively, and a constant deposition voltage of 30 V was applied for 50–60 s in the EPD process. The thickness of the coatings was controlled from 10 μm to 20 μm. The samples of composite coating were then sintered in a resistance tube furnace in flowing argon at 700 for 2 h. The structure of the as prepared coating was characterized by SEM and XRD, and the bonding force of the coating/substrate was measured by an interfacial shear strength test. It is shown that the bonding strengths between the coating and the titanium substrate is as high as 35 MPa. The cell culture experiments indicate that the prepared composite coating of HA/MWNTs possesses good biocompatibility.
Co-reporter:Ren Hu;Chang-Jian Lin;Hai-Yan Shi
Journal of Biomedical Materials Research Part A 2007 Volume 80A(Issue 3) pp:687-692
Publication Date(Web):15 NOV 2006
DOI:10.1002/jbm.a.30891
A novel porous nano hydroxyapatite (HA) coating has been prepared on commercially pure titanium substrate by a modified electrochemical deposition method. The physico-chemical and biological properties of the coating were characterized by SEM, XRD, FTIR, Raman, and in vitro cell culture test respectively. The SEM patterns show a uniform microporous morphology consisting of wirelike crystals at nanometer scale. It is suggested that under controlled deposition conditions, the primary HA nanowires grow and self-assemble to construct an ordered microporous nest-like morphology, thus to form a nano-micro two-level structure. The XRD results demonstrate that the HA nanowires are orderly arranged with their c-axis preferentially perpendicular to the substrate surface. The Raman and IR spectra affirm that the main component of the coating is well crystallized HA. An interdigitation phenomenon of the MG63 human osteosarcoma cells with the HA nanowires is observed in the in vitro test, indicating excellent biocompatibility and bioactivity for the prepared coating. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Co-reporter:J. Zuo, C.G. Nie, X. Gu, Y.K. Lai, Y. Zong, L. Sun, C.J. Lin
Materials Letters 2007 Volume 61(Issue 13) pp:2632-2637
Publication Date(Web):May 2007
DOI:10.1016/j.matlet.2006.10.010
A novel method to fabricate large scale TiO2/Au nanorod array using a positive sacrificial ZnO template has been developed. This method includes a two-step process, (1) preparation of ZnO/Au nanorod array by a simple low-temperature hydrothermal process, and (2) preparation of TiO2/Au nanorod array by electrochemically induced sol–gel process. The TiO2/Au nanorod array has showed a reversible electrochromism in lithium-ion-containing organic electrolyte. The coloration and bleaching throughout a visible range can be switched on and off within a few seconds.
Co-reporter:Yan Zhao, Changjian Lin, Yan Li, Ronggui Du, Jingrun Wang
Acta Physico-Chimica Sinica 2007 Volume 23(Issue 9) pp:1342-1346
Publication Date(Web):September 2007
DOI:10.1016/S1872-1508(07)60070-9
Comparing with pure copper, the corrosion behavior of copper clad laminate (CCL) in NaCl solution was studied by using linear polarization, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). It was shown that the CCL had a different corrosion behavior and showed a lower corrosion resistance compared with the pure copper. At low polarization potential, CCL dissolves through the formation of CuCl2–, which may be a determined step in the anodic process. And when the polarization potential increased, a porous film containing CuCl formed on the CCL surface, and the transportation of Cl– in the film became the controlling step in the corrosion process. An inductive loop at low frequency was observed in the EIS measurement, which was attributed to the modulation of CuCl film due to the competition between dissolution and growth processes on CCL surface.
Co-reporter:F. Chen;W. M. Lam;C. J. Lin;G. X. Qiu;Z. H. Wu;K. D. K. Luk;W. W. Lu
Journal of Biomedical Materials Research Part B: Applied Biomaterials 2007 Volume 82B(Issue 1) pp:183-191
Publication Date(Web):14 NOV 2006
DOI:10.1002/jbm.b.30720
A nano hydroxyapatite (HAp) layer was coated on a roughen titanium surface by means of electrophoretic deposition with an acetic anhydride solvent system. The objectives of this current study are to investigate whether nano-HAp can improve mechanical strength at a lower sintering temperature and biocompatibility. Densification temperature was lowered from usual 1000 to 800°C. The coating interfacial bonding strength, phase purity, microstructure, and biocompatibility were investigated. Degradation of HA phase was not detected in XRD. A porous TiO2 layer acts as a gradient coating layer with an intermediate thermal expansion coefficient between hydroxyapatite and titanium that reduces the thermal stress. From SEM image, the coating does not contain any crack. Mesenchymal stem cell (MSC) is the progenitor cell for various tissues in mature animals, which can improve integration of bone tissue into implant. In this in vitro study, rabbit MSCs culture indicated that the HAp/Ti nanocomposite biomaterial had good biocompatibility and bioactivity. Around materials and on its surface cell grew well with good morphology. Proliferation of the MSCs on the nano-HAp coating was higher than its micron counterpart in XTT assay. These properties show potential for the orthopaedic and dental applications. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Co-reporter:Xin Gu, Chageng Nie, Yuekun Lai, Changjian Lin
Materials Chemistry and Physics 2006 Volume 96(2–3) pp:217-222
Publication Date(Web):10 April 2006
DOI:10.1016/j.matchemphys.2005.07.006
A simple, template-less, self-seed and aqueous-phase synthesis of bicrystalline silver nanorods and nanowires is described and potassium tartaric was used as a reductant to reduce silver nitrate (AgNO3) for the first time in the presence of poly (vinyl pyrrolidone) (PVP). By changing the AgNO3/PVP ratio, the diameter and length of silver nanorods and nanowires can be controlled. The end-to-end assembly of the silver nanorods was found. It is indicated that, from the selected-area electron diffraction (SAED) study, the silver nanocrystals are generated with a bicrystalline structure. The effect of the concentration of NaOH is investigated and the reactions taken place during the formation of nanostructure silver is proposed.
Co-reporter:Yu Wang Dr.;Xin Xu Dr.;Zhongqun Tian Dr.;Ye Zong;Huiming Cheng Dr. Dr.
Chemistry - A European Journal 2006 Volume 12(Issue 9) pp:
Publication Date(Web):3 JAN 2006
DOI:10.1002/chem.200501010
We present a novel approach to the in situ deposition of size-controlled platinum nanoparticles on the exterior walls of carbon nanotubes (CNTs). The reduction of metal ions in ethylene glycol (EG), by the addition of a salt such as sodium dodecyl sulfate (SDS), p-CH3C6H4SO3Na, LiCF3SO3, or LiClO4, results in high dispersions and high loadings of platinum nanoparticles on CNTs without aggregation. We have performed controlled experiments to elucidate the mechanism. By exploiting the salt effect, our method effectively depresses homogeneous nucleation, leading to selective heterogeneous metal nucleation and growth, even on unmodified CNTs. In the 2.3–9.6 nm size range, the size of platinum nanoparticles, at 50 % loading, can be controlled by changing the concentration of metal ions, the reaction temperature, the reducing reagent or the means by which reactive solutions are added. Our method provides a flexible route towards the preparation of novel one-dimensional hybrid materials, for which a number of promising applications in a variety of fields can be envisioned.
Co-reporter:Ying Chen, Xin Gu, Cha-Geng Nie, Zhi-Yuan Jiang, Zhao-Xiong Xie and Chang-Jian Lin
Chemical Communications 2005 (Issue 33) pp:4181-4183
Publication Date(Web):13 Jul 2005
DOI:10.1039/B504911C
The shape of gold nanoparticles has been successfully tuned among penta-twinned decahedrons, truncated tetrahedrons, cubes, octahedrons, hexagonal thin plates by introducing a small amount of salt into a N,N-dimethylformamide (DMF) solution containing poly(vinyl pyrrolidone)
(PVP), and changing the temperature or the concentration of the gold precursor.
Co-reporter:G.X. Shen, Y.C. Chen, L. Lin, C.J. Lin, D. Scantlebury
Electrochimica Acta 2005 Volume 50(25–26) pp:5083-5089
Publication Date(Web):5 September 2005
DOI:10.1016/j.electacta.2005.04.048
A uniform TiO2 nanoparticle film has been coated on the surface of 316L stainless steel by using sol–gel and dip-coating technology. A hydrothermal post-treatment method has been developed to eliminate the crack defects in the coatings, and to improve the structure and property for the coating. A self-assembly of fluoroalkylsiane (FAS-13) has been conducted to enhance the surface hydrophobic property of the nano-TiO2 coatings. The distribution of particle sizes of TiO2 sol has been analyzed by ζ-potential analysis, and the surface morphology and structure have been characterized by contract angle, XRD, and SEM measurements. The results indicate that the surface of coatings is uniform and dense, with approximately 375 nm thickness. The diameter of particles of TiO2 anatase is in the range of 15–18 nm. The contact angle of the super-hydrophobic surface is 150 ± 1°. It shows, from the electrochemical tests, that the super-hydrophobic coatings on 316L stainless steel exhibit an excellent corrosion resistance in chloride containing solution at the room temperature.
Co-reporter:Y.K. Lai, L. Sun, C. Chen, C.G. Nie, J. Zuo, C.J. Lin
Applied Surface Science 2005 Volume 252(Issue 4) pp:1101-1106
Publication Date(Web):15 November 2005
DOI:10.1016/j.apsusc.2005.02.035
Abstract
Novel oriented aligned TiO2 nanotube (TN) arrays were fabricated by anodizing titanium foil in 0.5% HF electrolyte solution. It is indicated that the sizes of the TNs greatly depended on the applied voltages to some extent. The electrical properties of the TN arrays were characterized by current–voltage (I–V) measurements. It exhibits a nonlinear, asymmetric I–V characterization, which can be explained that there exists an n-type semiconductor/metal Schottky barrier diode between TN arrays and titanium substrate interface. The absorption edges shift towards shorter wavelengths with the decrease of the anodizing voltages, which is attributed to the quantum size effects. At room temperature, a novel wide PL band consisting of four overlapped peaks was observed in the photoluminescence (PL) measurements of the TN arrays. Such peaks were proposed to be resulted from the direct transition X1 → X2/X1, indirect transition Γ1 → X2/X1, self-trapped excitons and oxygen vacancies, respectively.
Co-reporter:G.X. Shen, Y.C. Chen, C.J. Lin
Thin Solid Films 2005 Volume 489(1–2) pp:130-136
Publication Date(Web):1 October 2005
DOI:10.1016/j.tsf.2005.05.016
A uniform and TiO2 nanoparticle coating on steels has been prepared using sol–gel method and hydrothermal post-treatments. The morphology and structure of the coatings were analysed using atomic force microscopy and X-ray diffraction. The anticorrosion performances of the coatings in dark and under ultraviolet illumination have been evaluated by using electrochemical techniques. The influences of coating thickness, pH and NaCl concentration on corrosion protection have been examined as well. The results indicate that the TiO2 nanoparticle coatings on steels exhibit an excellent corrosion resistance due to a ceramic protective barrier on metal surface in dark, and a photo-generated cathodic protection current under UV illumination. The electrochemical impedance spectroscopy measurements provide an explanation to the increased resistance of nano TiO2 particles coated 316 L stainless steel against corrosion.
Co-reporter:Lan Sun, Jinsheng Pan, Changjian Lin
Materials Letters 2003 Volume 57(Issue 7) pp:1239-1243
Publication Date(Web):January 2003
DOI:10.1016/S0167-577X(02)00965-5
Co-reporter:Li-Jiang Chen, Xuan Cheng, Chang-Jian Lin, Chao-Ming Huang
Electrochimica Acta 2002 Volume 47(Issue 9) pp:1475-1480
Publication Date(Web):15 February 2002
DOI:10.1016/S0013-4686(01)00872-6
Many concerns have been raised about the mechanism of cathode reaction in molten carbonate fuel cell (MCFC). The chemical behavior of oxide species at cathode in molten carbonate is a key for understanding the process of cathode reactions. In this paper, the variety and role of the oxide species in both bulk and thin-film of basic molten carbonates were investigated by using a novel in-situ Raman spectroscopy. The results indicated that the dominant oxide species under basic conditions was peroxide ion, and it was possible to transform into the oxygen of crystalline lattice during the lithium-doped process. It was demonstrated that in-situ Raman spectroscopic technique was a promising tool to elucidate the mechanism of electrode reaction in molecular level in the MCFC condition.
Co-reporter:Lan Sun, Jinsheng Pan, Changjian Lin
Materials Letters 2002 Volume 57(Issue 4) pp:1010-1014
Publication Date(Web):December 2002
DOI:10.1016/S0167-577X(02)00915-1
A new kind of matrix containing SiC whiskers for ∅ 105 diamond circular sawblades was developed. Test on the mechanical properties of the matrix and cutting performances of the sawblades indicated that the matrix had appropriate hardness and high bending strength. Sawing test on cutting performance in a stone factory proved that the sawblades made with the new formula had high cutting efficiency and long lifetime during the sawing of granites. The results showed its promising applications.
Co-reporter:Fei Chen, Zhou-Cheng Wang, Chang-Jian Lin
Materials Letters 2002 Volume 57(Issue 4) pp:858-861
Publication Date(Web):December 2002
DOI:10.1016/S0167-577X(02)00885-6
Natural bone is actually an inorganic/organic composite mainly made up of nano-structure hydroxyapatite (Ca10(PO4)6(OH)2, HAp) and collagen fibers. It is of most importance to synthesize nano-composites of inorganic/organic in order to have good biocompatibility, high bioactivity and great bonding properties. In this work, HAp nano-particle and HAp/chitosan (CTS) nano-composite with a homogeneous microstructure were prepared and characterized. It is proposed that the nano-structure of hydroxyapatite/chitosan composite will have the best biomedical properties in the biomaterials applications.
Co-reporter:Li-Jiang Chen, Chang-Jian Lin, Xuan Cheng, Zu-De Feng
Solid State Ionics 2002 Volume 148(3–4) pp:539-544
Publication Date(Web):2 June 2002
DOI:10.1016/S0167-2738(02)00096-6
A home-made LVDT displacement-measuring system was developed and applied to study the process of deformation on NiO during early stage of molten carbonate fuel cell (MCFC) operation. A series of in situ deformation tests was performed at a normal temperature (923 K) with porous Ni and NiO plaques under the atmospheres and load conditions in the presence of carbonate electrolyte. The results indicated that the most significant deformation took place when Ni plaque underwent both in situ oxidized and lithiated processes under a load condition, in particular, the deformation of Ni plaque occurred more severely at the beginning of processes.
Co-reporter:Liwen Lin, Hui Wang, Ming Ni, Yunfeng Rui, ... Changjian Lin
Journal of Orthopaedic Translation (January 2014) Volume 2(Issue 1) pp:35-42
Publication Date(Web):1 January 2014
DOI:10.1016/j.jot.2013.08.001
Biomimetic design and substrate-based surface modification of medical implants will help to improve the integration of tissue to its material interfaces. Surface energy, composition, roughness, and topography all influence the biological responses of the implants, such as protein adsorption and cell adhesion, proliferation and differentiation. In the current study, different surface structures of Ti implants were constructed using facile surface techniques to create various micro-, nano-, and nano/micro composite scale topography. We have fabricated three types of hierarchical structures of TiO2 coating on Ti implants, including nanotube structure, nano sponge-like structure, and nano/micro nest-like structure. The osteointegration and biomechanical performance of the coated Ti screws were evaluated by histology and removal of torque force test in vivo. We found that the nano/micro nest-like and nanotube structured surface possessed better osteointegration ability. It indicated that the alkaline hydrothermally treated Ti substrate was the best for bone-implant integration in terms of all in vitro and in vivo testing parameters. The alkaline hydrothermally treated surface displayed a hydrophilic (contact angle value 5.92 ± 1.2), higher roughness (Ra value 911.3 ± 33.8 nm), higher specific surface area (8.26 ± 1.051 m2/g), and greater apatite inductivity. The electrochemical surface modification may become a powerful approach to enhance metal implant to bone integration in orthopaedic applications.
Co-reporter:Jiaojiao Gong, Changjian Lin, Meidan Ye and Yuekun Lai
Chemical Communications 2011 - vol. 47(Issue 9) pp:NaN2600-2600
Publication Date(Web):2010/12/20
DOI:10.1039/C0CC04407E
A novel nanocomposite TiO2 film consisting of a bamboo leaf-like nano TiO2 layer on a nanotubular TiO2 arrays surface is synthesized by electrochemical anodization with wet chemical pretreatment; it shows almost three times higher activity as compared to that of nanotubular TiO2 arrays alone.
Co-reporter:Chang Chen, Meidan Ye, Nan Zhang, Xiaoru Wen, Dajiang Zheng and Changjian Lin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 12) pp:NaN6314-6314
Publication Date(Web):2015/02/09
DOI:10.1039/C4TA06987K
Hollow Co9S8 nanoneedle arrays directly grown on fluorine-doped tin oxide (FTO) transparent conducting substrates were successfully prepared using a simple sacrificial template method. The performances of CdS/CdSe quantum dot-sensitized solar cells (QDSCs) employing such Co9S8 counter electrodes were remarkably improved compared to those using conventional Pt counter electrodes, primarily due to their higher electrocatalytic activity in the reduction of polysulfide electrolytes.
Co-reporter:Ran Song, Jianhe Liang, Longxiang Lin, Yanmei Zhang, Yun Yang and Changjian Lin
Journal of Materials Chemistry A 2016 - vol. 4(Issue 22) pp:NaN4024-4024
Publication Date(Web):2016/05/06
DOI:10.1039/C6TB00458J
Base on a superhydrophobic–superhydrophilic micro-patterned template, a facile construction of gradient micro-patterned octacalcium phosphate (OCP) coatings on titanium has been firstly developed for high-throughput evaluation of biocompatibility. The gradient OCP coatings with tunable crystal morphologies involving scattered-flower-like, scattered-flower-ribbon-like, short-ribbon-like and long-ribbon-like were fabricated in different micro-units on the same surface. The significant difference of mineralization behavior of the gradient OCP coatings in the micro-patterns was observed visually and efficiently. In vitro cultures of MC3T3-E1 cells showed that the number and morphology of cells selectively adhered on the micro-units of gradient structure of OCP coatings were distinctly different, indicating that the cells are sensitive to the different structures of OCP coatings on medical titanium. The gradient micro-patterned construction is potentially a powerful method for not only high-throughput screening of the biocompatibility of various biomaterials, but also efficient development of advanced biomaterials by controlling cell immobilization and inducing cell response.
Co-reporter:Meidan Ye, Xiaoru Wen, Nan Zhang, Wenxi Guo, Xiangyang Liu and Changjian Lin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 18) pp:NaN9600-9600
Publication Date(Web):2015/03/16
DOI:10.1039/C5TA00390C
Vertical CuS nanosheet arrays were synthesized in situ for the first time on transparent conducting fluorine-doped tin oxide (FTO) substrates via a facile solvothermal process of seeded FTO glasses in the presence of ethanol solvent only containing thiourea and Cu(NO3)2 as a precursor. While choosing CuCl instead of Cu(NO3)2 as the copper precursor in the same solvothermal process, porous Cu1.8S nanosheets, for the first time, were also vertically grown on FTO substrates, suggesting that such a synthesis process is a general approach for the preparation of copper sulfide nanosheet arrays. When used as low-cost counter electrode materials in quantum dot-sensitized solar cells (QDSSCs), CuS (3.95%) and Cu1.8S (3.30%) nanosheet films exhibited enhanced power conversion efficiencies in comparison with the conventional Pt film (1.99%), which was primarily due to the excellent electrocatalytic activity of copper sulfides for the reduction of the polysulfide electrolyte used in CdSe/CdS QDSSCs. Significantly, the in situ growth strategy largely simplified the fabrication procedure of copper sulfide counter electrodes and, meanwhile, enhanced the adhesion between films and substrates.
Co-reporter:Mengye Wang, Xinchang Pang, Dajiang Zheng, Yanjie He, Lan Sun, Changjian Lin and Zhiqun Lin
Journal of Materials Chemistry A 2016 - vol. 4(Issue 19) pp:NaN7199-7199
Publication Date(Web):2016/03/18
DOI:10.1039/C6TA01838F
The ability to synthetically tune the size, shape, composition and architecture of inorganic nanostructures offers enormous opportunities to explore the fundamental structure–property relationships that occur uniquely at the nanoscale, and engineer greater functionality and design complexity into new material systems. Core/shell nanoparticles represent an important class of nanostructured materials that have garnered considerable interest. The success in producing core/shell nanoparticles with strictly controlled core diameter and shell thickness and tailoring their material properties relies crucially on the epitaxial growth of the shell material over the highly curved surface of the spherical core. However, effective methods to yield such high-quality core/shell nanoparticles are comparatively few and limited in scope. Here, we develop a robust nonepitaxial growth strategy to create uniform plasmonic/semiconducting core/shell nanoparticles with precisely controlled dimensions by capitalizing on amphiphilic star-like triblock copolymers as nanoreactors. The diameter of the plasmonic core and the thickness of the semiconductor shell can be independently and precisely regulated by tailoring the molecular weights (i.e., the lengths) of the inner and intermediate blocks of star-like triblock copolymers, respectively. The successful crafting of plasmonic/semiconducting core/shell nanoparticles was corroborated by the composition and structural characterizations. These functional nanoparticles exhibited largely improved photocatalytic activities, which can be attributed to the localized surface plasmon-mediated light harvesting enhancement of the plasmonic core and the built-in internal electric field. This nonepitaxial growth strategy offers new levels of tailorability in the dimensions, compositions and architectures of nanomaterials with engineered functionalities for applications in catalytic, electronic, optic, optoelectronic and sensory materials and devices.
Co-reporter:Zhi Wu, Cheng Gong, Jiangdong Yu, Lan Sun, Wang Xiao and Changjian Lin
Journal of Materials Chemistry A 2017 - vol. 5(Issue 3) pp:NaN1299-1299
Publication Date(Web):2016/12/07
DOI:10.1039/C6TA07420K
Photoelectrocatalytic efficiency is mainly dependent on the light absorption of a photocatalyst electrode, charge separation and transport, and surface chemical reactions. To enhance photoelectrocatalytic efficiency, an ordered one-dimensional heterojunction photocatalyst consisting of CuxZn1−xIn2S4 ultrathin nanosheets on electrochemically anodized TiO2 nanotube arrays (CZIS@TNTAs) was successfully synthesized by a solvothermal reaction. It was found that the CuxZn1−xIn2S4 ultrathin nanosheets on the TNTAs significantly enhanced visible light absorption and photoelectrochemical responses, and a near 8.0-fold increase in the photoelectrocatalytic hydrogen production rate was achieved compared to the blank TNTAs. Moreover, the CZIS@TNTAs exhibited excellent photoelectrocatalytic stability. Measurements of the flat-band and electrochemical impedance revealed the feasibility of charge transfer in the CZIS@TNTA hetero-systems, which was supported by PL and photoelectrochemical measurements. The superior photoelectrocatalytic activity of the CZIS@TNTA composite electrodes is mainly attributed to their enhanced light absorption and the separation of photo-generated charges, facilitating electron transport along the 1D TiO2 structure.
Co-reporter:Xiaoru Wen, Jiamin Wu, Meidan Ye, Di Gao and Changjian Lin
Chemical Communications 2016 - vol. 52(Issue 76) pp:NaN11358-11358
Publication Date(Web):2016/08/25
DOI:10.1039/C6CC06290C
A tunnelling contact of polystyrene nanofilm was introduced for the first time at the interface of perovskite/hole transfer layer, leading to a significantly reduced charge recombination. Moreover, such a polymeric contact worked as a hydrophobic encapsulation layer for effectively protecting the perovskite against humidity. The resultant PSCs displayed a peak efficiency of 17.80% (vs. 15.90% of the control cell) and an enhanced stability.
Co-reporter:Xiaoru Wen, Jiamin Wu, Di Gao and Changjian Lin
Journal of Materials Chemistry A 2016 - vol. 4(Issue 35) pp:NaN13487-13487
Publication Date(Web):2016/08/01
DOI:10.1039/C6TA04616A
In pursuit of reducing the surface trap states of perovskite as well as enhancing the hole control of dopant-free spiro-OMeTAD, an amino-rich graphene (NGs) was introduced via a facial solution method as an interlayer at the perovskite/HTM interface. A number of characterizations, including photoluminescence and impedance spectroscopy, was conducted to reveal the interfacial effect of the NGs, and it was demonstrated that the amino group facilitated the reduced surface trap of perovskite and that graphene could behave as an efficient hole extraction and transfer pathway through the HTM network. Consequently, a maximum PCE of 14.6% could be obtained, which represented a remarkable improvement of ca. 36% over the control device (10.7%), with the improvement mainly related to the increase of JSC and FF.
