Co-reporter:Zhenggong Wang;Dong Wang;Jian Niu
Langmuir February 10, 2015 Volume 31(Issue 5) pp:1670-1674
Publication Date(Web):2017-2-22
DOI:10.1021/acs.langmuir.5b00053
Oil/water separation has been a worldwide subject because of increasing release of oil-containing wastewater as well as several marine oil spills. The phase-selective organogelators (PSOGs) are thought to offer a potential and effective implement for addressing this issue. An ideal PSOG for oil adsorption must fulfill some requirements involving effective gelation, easy synthesis, low cost, and recyclable for reuse. However, beyond those, the ability of gelation for a broad-range oil phase without selectivity is also important. However, most of the reported PSOGs have limitation in this respect thus far. In this paper, a new class of saturated 1-monoglyceride-derived organogelators can efficiently uptake almost all of the common fuel oils from water and gelate organic solvents with extremely low minimum gelation concentration (MGC). In addition, the oils in the gel and gelator molecules can be recovered quantitatively through simple vacuum distillation.
Co-reporter:Feng Zhang;Haili Qin;Liang Hu;Shenxiang Zhang
Langmuir August 18, 2015 Volume 31(Issue 32) pp:8795-8801
Publication Date(Web):2017-2-22
DOI:10.1021/acs.langmuir.5b01879
Exploration of an effective route to achieve the controlled growth of two-dimensional (2D) molecular crystal is of scientific significance yet greatly underdeveloped due to the complexity of weak intermolecular interactions, thus leading to difficulty of inducing anisotropic 2D growth. We report here a facile nanowire oriented on-surface growth strategy for the fabrication of cystine crystalline nanosheets with finely controlled thickness (1.1, 1.9, 2.9, and 4.8 nm which correspond to one layer, two layers, three layers, and five layers of crystal cystine, respectively) and large areas (>100 μm2). The cystine crystalline nanosheets display chirality delivered by chiral cysteine monomers, either l-cysteine or d-cysteine. The chiral nanosheets with structural precision and chemical diversity could serve as a novel 2D platform for constructing advanced hybrid materials.
Co-reporter:Lei Wang, Yihan Zhu, Zhenhua Zeng, Chong Lin, Michael Giroux, Lin Jiang, Yu Han, Jeffrey Greeley, Chao Wang, Jian Jin
Nano Energy 2017 Volume 31() pp:456-461
Publication Date(Web):January 2017
DOI:10.1016/j.nanoen.2016.11.048
•Developed the overgrowth of Pt nanocrystals on single-layer Ni(OH)2 nanosheets•Demonstrated 5-times improvement in electrocatalytic activity for water reduction•Revealed a Pt-Ni-OH type of interface as the catalytically active sites•Depicted the reaction pathway of water reduction at the Pt-Ni-OH interfaceWater electrolysis represents a promising solution for storage of renewable but intermittent electrical energy in hydrogen molecules. This technology is however challenged by the lack of efficient electrocatalysts for the hydrogen and oxygen evolution reactions. Here we report on the synthesis of platinum-nickel hydroxide nanocomposites and their electrocatalytic applications for water reduction. An in situ reduction strategy taking advantage of the Ni(II)/Ni(III) redox has been developed to enable and regulate the overgrowth of Pt nanocrystals on single-layer Ni(OH)2 nanosheets. The obtained nanocomposites (denoted as Pt@2D-Ni(OH)2) exhibit an improvement factor of 5 in catalytic activity and a reduction of up to 130 mV in overpotential compared to Pt for the hydrogen evolution reaction (HER). A combination of electron microscopy/spectroscopy characterizations, electrochemical studies and density function theory calculations was employed to uncover the structures of the metal-hydroxide interface and understand the mechanisms of catalytic enhancement.
Co-reporter:Chong Lin;Guanghao Wu;Huiqin Li;Yanmin Geng;Gang Xie;Jianhui Yang;Bin Liu
Nanoscale (2009-Present) 2017 vol. 9(Issue 5) pp:1834-1839
Publication Date(Web):2017/02/02
DOI:10.1039/C6NR09739A
We reported a facile and scalable salt-templated approach to produce monodisperse Rh nanoparticles (NPs) on ultrathin carbon nanosheets with the assistance of calcination under inert gas. More importantly, in spite of the essentially poor ORR activity of Rh/C, the acquired Rh/C hybrid nanosheets display a comparable ORR activity to the optimal commercial Pt/C catalyst, which may be due to the extra-small size of Rh NPs and the 2D defect-rich amorphous carbon nanosheets that can facilitate the charge transfer and reactive surface exposure. Moreover, Rh/C nanosheets present the optimal current density and best durability with the minimum decline during the entire test, so that ∼93% activity after 20 000 s is achieved, indicating a good lifetime for ORR. In contrast, commercial Pt/C and commercial Rh/C exhibited worse durability, so that ∼74% and ∼85% activities after 20 000 s are maintained. What's more, in the model system of reduction of 4-nitrophenol (4-NP), the kinetic constant k for Rh/C nanosheets is 3.1 × 10−3, which is 4.5 times than that of the commercial Rh/C catalyst, revealing that our Rh/C hybrid nanosheets can be potentially applied in industrial catalytic hydrogenation. This work opens a novel and facile way for the rest of the precious metal NPs to be supported on ultrathin carbon nanosheets for heterogeneous catalysis.
Co-reporter:Wenbin Zhang;Liang Hu;Hanmei Chen;Shoujian Gao;Xiangcheng Zhang
Journal of Materials Chemistry B 2017 vol. 5(Issue 25) pp:4876-4882
Publication Date(Web):2017/06/28
DOI:10.1039/C7TB00644F
Separation of plasma from whole blood is requisite for the accurate measurement of glucose levels. From the wettability point of view, in this study, we report the fabrication of a mineralized Janus membrane with an asymmetric wetting property; this membrane can transport fast microliter-quantity blood and separate out the red blood cells. The membrane is composed of a hydroxyapatite (HAP)-mineralized polyvinylidene fluoride (PVDF) membrane prepared via an interface diffusion-controlled chemical precipitation method. Due to gradient distribution of the HAP nanocrystals across the PVDF membrane, the composite membrane exhibits an asymmetric wetting property where a tiny whole blood droplet (13 μL) can spontaneously permeate across the membrane within 20 s and red blood cells in the whole blood are successfully blocked by the membrane. The membrane is then integrated into blood glucometers for accurate measurements of the glucose levels. The results show that the porous membrane can successfully prevent red blood cells in whole blood from entering the enzyme layer; moreover, the negative effect of hematocrit levels on the blood glucose measurements is effectively minimized and an obviously high and stable glucose current signal is achieved.
Co-reporter:Zhenggong Wang;Huiting Ren;Shenxiang Zhang;Feng Zhang
Journal of Materials Chemistry A 2017 vol. 5(Issue 22) pp:10968-10977
Publication Date(Web):2017/06/06
DOI:10.1039/C7TA01773A
Mixed matrix membranes (MMMs), i.e., organic–inorganic hybrid membranes, are one of the most promising membranes for overcoming the performance limitations of conventional polymer membranes in gas separation. Polymers of intrinsic microporosity (PIMs) have received considerable research interest due to their high permeability arising from their rigid and contorted chain structure. However, interfacial issues in PIM-based hybrid membranes are serious due to the low mobility and flexibility of their polymer chains. We present in this work the fabrication of a PIM-based hybrid membrane using amidoxime-functionalized PIM-1 as the polymer matrix and an amine-functionalized metal–organic framework (MOF), NH2-UiO-66, as the inorganic filler. In the hybrid membrane, amidoxime and amine groups tend to form hydrogen bonds, creating a hydrogen bond network between the two phases. Therefore, a nearly ideal and defect-free interface is constructed. The well-designed hybrid membrane exhibits excellent separation performance, especially for CO2 capture, with a CO2 permeability as high as 8425 barrer and CO2/N2 and CO2/CH4 gas pair selectivities of up to 27.5 and 23.0, respectively. The overall separation performance of the hybrid membrane for CO2/N2 and CO2/CH4 surpasses the 2008-updated Robeson upper bound and is outstanding compared with those of existing mixed matrix membranes.
Co-reporter:Shenxiang Zhang;Zhenggong Wang;Huiting Ren;Feng Zhang
Journal of Materials Chemistry A 2017 vol. 5(Issue 5) pp:1962-1966
Publication Date(Web):2017/01/31
DOI:10.1039/C6TA09570D
An ultrathin and continuous ZIF-8 membrane as thin as ∼550 nm was fabricated via a spatially confined contra-diffusion process, in which a nanoporous network film is utilized as an interlayer mediator to control the nucleation and growth of ZIF-8 crystals. The membrane exhibits a high H2 permeance up to 6.31 × 10−7 mol m−2 s−1 pa−1 and simultaneously maintains a high ideal selectivity of 43 for H2/CO2.
Co-reporter:Zhenggong Wang;Dong Wang;Shenxiang Zhang;Liang Hu
Advanced Materials 2016 Volume 28( Issue 17) pp:3399-3405
Publication Date(Web):
DOI:10.1002/adma.201504982
Co-reporter:Shoujian Gao;Jichao Sun;Pingping Liu;Feng Zhang;Wenbin Zhang;Shiling Yuan;Jingye Li
Advanced Materials 2016 Volume 28( Issue 26) pp:5307-5314
Publication Date(Web):
DOI:10.1002/adma.201600417
Co-reporter:Chong Lin, Weikun Zhang, Lei Wang, Zhenggong Wang, Wen Zhao, Wenhui Duan, Zhigang Zhao, Bin Liu and Jian Jin
Journal of Materials Chemistry A 2016 vol. 4(Issue 16) pp:5993-5998
Publication Date(Web):21 Mar 2016
DOI:10.1039/C5TA10307J
We report in this work a new type composite separator that contains a conductive few-layered Ti3C2 nanosheet and a glass fiber (GF) membrane for lithium–sulfur (Li–S) batteries. Using commercial bulk S (particle size 2–10 μm) as the cathode directly, the Li–S battery delivers an initial discharge capacity of 820 mA h g−1 at a current density of 0.5 A g−1 and a discharge capacity of 721 mA h g−1 after 100 cycles.
Co-reporter:Yuzhang Zhu, Shoujian Gao, Liang Hu, and Jian Jin
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 21) pp:13607-13614
Publication Date(Web):May 13, 2016
DOI:10.1021/acsami.6b03389
With the growing demand for small- and large-scale bioprocesses, advanced membranes with high energy efficiency are highly required. However, conventional polymer-based membranes often have to sacrifice selectivity for permeability. In this work, we report the fabrication of a thermoresponsive composite ultrathin membrane with precisely controlled nanopores for high-throughput separation. The composite membrane is made by grafting a PEG analogue thermoresponsive copolymer onto an ultrathin single-wall carbon nanotubes (SWCNTs) membrane via π–π interaction with no use of the common “grafting from” synthesis approach. The composite membrane exhibits ultrahigh water permeation flux as high as 6430 L m–2 h–1 at 40 °C, and more importantly, the pore size of the membrane could be finely adjusted by utilizing the thermoresponsive property of the grafted copolymer. With the temperature changing below and above the lower critical solution temperature (LCST) of the copolymer, the effective pore size of the membrane can be tuned precisely between approximately 12 and 14 nm, which could be applied to effectively separate materials with very small size differences through size sieving.
Co-reporter:Yang Yang;Dong Wang;Yongjin Wu;Xiaorui Tian;Haili Qin;Liang Hu;Ting Zhang;Weihai Ni
Macromolecular Rapid Communications 2016 Volume 37( Issue 7) pp:590-596
Publication Date(Web):
DOI:10.1002/marc.201500698
Co-reporter:Haili Qin, Fujin Li, Dong Wang, Hongzhen Lin, and Jian Jin
ACS Nano 2016 Volume 10(Issue 1) pp:948
Publication Date(Web):December 21, 2015
DOI:10.1021/acsnano.5b06149
The orientation and state of organization of polymer chains play significant roles in determining the final properties and functions of these materials. Unlike most semicrystalline polymers, which have an inherent driving force toward crystallization, the means to control chain packing in noncrystallizable polymers is still restricted and remains a challenge. We report herein a 2D soft template-directed fabrication for ultrathin polyacrylamide nanosheets with a thickness as low as 3.5 nm and large dimensions (>20 μm). More importantly, the polymer chains in the nanosheets produced are well aligned with a clear interchain spacing. The formation of polymer nanosheets with ordered chain alignment was performed in a special solution containing a periodic sandwich structure of lamellar bilayer membranes and water layers that are hundreds of nanometers thick. It functions as a 2D orientation template to align the monomers in an orderly manner along the in-plane direction of the bimolecular membrane via hydrogen bonding.Keywords: 2D orientation template; 2D polymer; bimolecular membrane; chain alignment; ultrathin nanosheet;
Co-reporter:Lei Wang, Chong Lin, Dekang Huang, Jianmei Chen, Lin Jiang, Mingkui Wang, Lifeng Chi, Lin Shi, and Jian Jin
ACS Catalysis 2015 Volume 5(Issue 6) pp:3801
Publication Date(Web):May 13, 2015
DOI:10.1021/cs501835c
Hydrogen is considered by many to be a promising energy currency, particularly for the transportation sector and for mobile devices. To realize a hydrogen-based fuel economy, hydrogen must be produced in an efficient and sustainable manner. In this article, single-layer nickel hydroxide (Ni(OH)2)-nanosheet-assisted Pt/C catalysis for the hydrogen evolution reaction (HER) in an alkaline environment was investigated. The HER activity trajectories of the hybrid catalysts in correlation with the composition and morphology of Ni(OH)2 were explored in depth. By optimizing the Volmer step through addition of single-layer Ni(OH)2 into Pt/C catalysis, this hybrid catalyst manifests a 110% increase of the HER activity by using only 20 wt % single-layer Ni(OH)2 with a lithium ion additive as compared to the state-of-the-art Pt/C catalyst. Density functional theory calculations revealed that the single-layer Ni(OH)2 behaves superior in adsorption ability of OH– when compared with multilayer Ni(OH)2. The single-layer Ni(OH)2 contributes to dual improvement on both the Volmer step and the adsorption of OH– during HER.Keywords: density functional theory; hydrogen evolution reaction; Ni(OH)2/Pt composite; single-layer Ni(OH)2; the Volmer step
Co-reporter:Shou Jian Gao, Yu Zhang Zhu, Feng Zhang and Jian Jin
Journal of Materials Chemistry A 2015 vol. 3(Issue 6) pp:2895-2902
Publication Date(Web):15 Dec 2014
DOI:10.1039/C4TA05624H
Functional membranes with a superwetting surface property have been extensively explored to achieve oil–water separation. Here, single-walled carbon nanotube/polydopamine/polyethyleneimine (SWCNT/PD/PEI) composite ultrathin films which have superhydrophilic and underwater superoleophobic properties were successfully prepared and used for the ultrafast separation of surfactant-stabilized oil-in-water nanoemulsions containing oil droplets of tens of nanometers. A SWCNT/PD/PEI composite film with an effective pore size of ∼10 nm and a thickness of ∼160 nm can effectively separate oil-in-water nanoemulsions in an ultrafast manner with fluxes up to ∼6000 L m−2 h−1 bar−1, which is 10-fold higher than traditional ultrafiltration membranes with a similar rejection property. Meanwhile, this film exhibits excellent pH-stability and antifouling property. This work points a direction for designing and fabricating ultrathin and superwetting films for the effective separation of oil-in-water nanoemulsions or nano-sized oils which are hard to separate by traditional methods. The SWCNT/PD/PEI ultrathin film holds promising potential for purifying emulsified wastewater from industries and daily life and for drinking water treatment.
Co-reporter:Shou Jian Gao, Haili Qin, Pingping Liu and Jian Jin
Journal of Materials Chemistry A 2015 vol. 3(Issue 12) pp:6649-6654
Publication Date(Web):16 Feb 2015
DOI:10.1039/C5TA00366K
Laminar separation membranes fabricated with two-dimensional nanomaterials have been extensively explored to achieve the separation of molecules and water purification. Herein, single-walled carbon nanotube (SWCNT)-intercalated graphene oxide (GO) ultrathin laminar films are successfully prepared and used for the separation of molecules with sizes greater than 1.8 nm. Nanochannels created by the intercalation of SWCNT into GO layers greatly improve water permeation compared with pure GO films without sacrificing the rejection of nanometer-scale particles and molecules. A SWCNT-intercalated GO film with a thickness of 40 nm can effectively separate Bovine Serum Albumin, cytochrome c, Coomassie Brilliant Blue and Rhodamine B with fluxes of 660–720 L m−2 h−1 bar−1, which are about 10-fold higher than the fluxes of traditional nanofiltration membranes with similar rejection properties. The films also exhibit high separation efficiencies of 97.4% to 98.7%. Moreover, the SWCNT-intercalated GO films exhibit excellent pH-stabilities when used in extreme pH conditions, and it is superior to most of the ceramic- and polymer-based membranes. The SWCNT-intercalated GO films have a promising potential to be used as advanced separation membranes for water purification and chemical refinement.
Co-reporter:Liang Hu, Shoujian Gao, Yuzhang Zhu, Feng Zhang, Lei Jiang and Jian Jin
Journal of Materials Chemistry A 2015 vol. 3(Issue 46) pp:23477-23482
Publication Date(Web):14 Oct 2015
DOI:10.1039/C5TA03975D
Superwetting membranes offer a good platform for oil/water separation, but the generation of responsive membranes for on-demand oil/water emulsion separation with both high permeation flux and selectivity is still a challenge. Herein, bilayer membranes that feature asymmetric wettability across the membrane thickness are constructed, simply by depositing a thin layer of polydopamine-coated single-walled carbon nanotubes (SWCNTs) and subsequently coating with a SWCNT layer. When a low applied pressure difference across the membrane, Papplied, is utilized, the hydrophobic–superoleophilic surface is critical for the separation of surfactant-stabilized water-in-oil emulsions. Triggered by an intensive Papplied, surfactant-stabilized oil-in-water emulsions can also be fully separated by a synergistic effect of dual layers. Such ultrathin bilayer membranes exhibit ultrahigh permeation flux and separation efficiency with excellent antifouling for both water-in-oil and oil-in-water emulsion separation in a single-unit, which is readily achieved by the modulation of Papplied. Therefore, we envision that our bilayer membranes show great potential in oil/water emulsion separation.
Co-reporter:Dong Wang, Zhenggong Wang, Lei Wang, Liang Hu and Jian Jin
Nanoscale 2015 vol. 7(Issue 42) pp:17649-17652
Publication Date(Web):05 Oct 2015
DOI:10.1039/C5NR06321C
Single-layered MoS2-based ultrathin membranes with well-controlled thicknesses are prepared by a simple filtration method, and for the first time applied to gas separation. These membranes exhibit superior H2/CO2 separation performance and extremely high H2 permeance. The H2/CO2 separation performance surpasses the state-of-the-art upper-bound of polymeric and inorganic membranes.
Co-reporter:Haili Qin, Xiong Xiong, Dongmin Wu, Feng Zhang, Dong Wang, Xia Liu, Wensheng Yang and Jian Jin
Chemical Communications 2015 vol. 51(Issue 10) pp:1957-1960
Publication Date(Web):15 Dec 2014
DOI:10.1039/C4CC09370D
A facile strategy for the fabrication of ultralarge (edge length >50 μm), single-crystalline Ag nanomembranes is reported in this work. The Ag nanomembrane with an atomically smooth surface demonstrates a much longer surface plasmonic propagation length as compared to vacuum-deposited polycrystalline Ag film, representing superior plasmonic properties.
Co-reporter:Yuzhang Zhu, Wei Xie, Jingye Li, Tieling Xing, Jian Jin
Journal of Membrane Science 2015 Volume 477() pp:131-138
Publication Date(Web):1 March 2015
DOI:10.1016/j.memsci.2014.12.026
•PEI was grafted onto PVDF blend membrane.•The PEI grafted membrane shows effective separation of acidic oil-in-water emulsion.•The membrane shows a superior antifouling performance for treating acidic emulsion.•The membrane behaves an excellent permeating performance with high flux.•The membrane shows a potential for treating acidic oily wastewater treatment.Membrane technology has been considered as one of the most efficient methods to treat oil contaminated water. However, due to serious fouling caused by oil droplets absorption, the development of membrane technology is impeded in treating oily wastewater. We report in this work the fabrication of a pH-induced non-fouling membrane by grafting hyperbranched poly (ethylene imine) (PEI) onto PVDF/polyacrylic acid grafted PVDF blend membrane for effectively separating viscous soybean oil-in-water emulsion. The membrane exhibits an ultralow oil-adhesion and thus displays a superior antifouling performance in acidic condition so that it maintains a stable flux for long-time permeating. Meanwhile, the PEI grafted blend membrane behaves an excellent permeating performance with high flux and high separation efficiency. It shows a promising potential for treating oil-contaminated wastewater produced by various industrial processes, especially for acidic oily wastewater treatment.
Co-reporter:Wenbin Zhang, Feng Zhang, Shoujian Gao, Yuzhang Zhu, Jingye Li, Jian Jin
Separation and Purification Technology 2015 Volume 156(Part 2) pp:207-214
Publication Date(Web):17 December 2015
DOI:10.1016/j.seppur.2015.09.076
•A hierarchical PAA-g-PVDF layer coated nickel foam membrane with superhydrophilicity and underwater superoleophobicity was fabricated.•The membrane could realize temperature-controlled separation of heavy oil/water mixtures.•Driven by gravity only, high separation efficiency and high flux for separation of heavy oil/water mixtures were achieved.•The membrane exhibited an excellent anti-heavy-oil-fouling property.Heavy crude oil/water separation is becoming a worldwide issue and a tougher challenging as compared to light crude oil due to its high viscosity. Herein, we report a facile approach for high-efficient heavy oil/water separation by combing superwetting membrane filtration with elevated temperature during separation process. Micro/nano hierarchical PAA-g-PVDF layer coated nickel foam membranes are successfully fabricated through a salt-induced phase inversion process. The PAA-g-PVDF coating layer endows the foam membrane a superhydrophilic and underwater superoleophobic property, and a low heavy-oil-adhesion force. At an elevated temperature (up to 85 °C) where the viscosity of heavy oil is dramatically decreased with the increase of temperature, the foam membranes are applicable for temperature-controlled separation of heavy oil/water mixture with various heavy oil/water volume ratio with high separation efficiency (the contents of heavy oil in the filtrate after one-time separation <20 ppm) and high flux up to ∼104 L m−2 h−1, solely driven by gravity. Most importantly, the foam membrane exhibits an excellent anti-heavy-oil-fouling property and is easily recycled for long-term use. The high separation performance with elevated temperature, combined with easy scale up, makes the foam membranes an attractive option for treating heavy oil containing wastewater.
Co-reporter:Liang Hu, Shoujian Gao, Xianguang Ding, Dong Wang, Jiang Jiang, Jian Jin, and Lei Jiang
ACS Nano 2015 Volume 9(Issue 5) pp:4835
Publication Date(Web):April 23, 2015
DOI:10.1021/nn5062854
Oil-contaminated wastewater threatens our environment and health, especially that stabilized by surfactants. Conventional separation protocols become invalid for those surfactant-stabilized nanoemulsions due to their nanometer-sized droplets and extremely high stability. In this paper, photothermal-responsive ultrathin Au nanorods/poly(N-isopropylacrylamide-co-acrylamide) cohybrid single-walled carbon nanotube (SWCNT) nanoporous membranes are constructed. Such membranes are capable of separating oil-in-water nanoemulsions with a maximum flux up to 35 890 m2·h–1·bar–1 because they feature hydrophilicity, underwater oleophobicity, and nanometer pore sizes. It is remarkable that the permeation flux can be simply modulated by light illumination during the process of separation, due to the incorporation of thermal-responsive copolymers and Au nanorods. Meanwhile, it shows ultrahigh separation efficiency (>99.99%) and desired antifouling and recyclability properties. We anticipate that our ultrathin photothermal-responsive SWCNT-based membranes provide potential for the generation of point-of-use water treatment devices.Keywords: emulsion separation; light-modulated flux; oil-in-water nanoemulsion; photothermal responsivity; ultrathin membrane;
Co-reporter:Yuzhang Zhu, Dong Wang, Lei Jiang and Jian Jin
NPG Asia Materials 2014 6(5) pp:e101
Publication Date(Web):2014-05-01
DOI:10.1038/am.2014.23
The separation of oily wastewater, especially emulsified oil/water mixtures, is a worldwide challenge because of the large amount of oily wastewater produced in many industrial processes and daily life. For the treatment of oily wastewater, membrane technology is considered the most efficient method because of its high separation efficiency and relatively simple operational process. In this short review, the recent development of advanced filtration membranes for emulsified oil/water mixture separation is presented. We provide an overview on both traditional filtration membranes, including polymer-dominated and ceramic-based filtration membranes, and recently developed nanomaterial-based functional filtration membranes, especially one-dimensional nanomaterials, for effectively treating emulsified oil/water mixtures. The liquid flux and antifouling property, which are the most important factors for membrane performance evaluation, are described for different types of membranes. Conclusions and perspectives concerning the future development of filtration membranes are also provided.
Co-reporter:Zhihui Dong, Dong Wang, Xia Liu, Xianfeng Pei, Liwei Chen and Jian Jin
Journal of Materials Chemistry A 2014 vol. 2(Issue 14) pp:5034-5040
Publication Date(Web):20 Jan 2014
DOI:10.1039/C3TA14751G
By utilizing the synergistic effect of poly-dopamine (PD) with functional groups and graphene oxide (GO) with a high surface area, a series of sub-nano thick PD layer coated GO (PD/GO) composites were fabricated by a well-controlled self-polymerization of dopamine via catechol chemistry and used for effectively decontaminating wastewater. The obtained PD/GO could selectively adsorb the dyes containing an Eschenmoser structure and showed an extremely high adsorption capacity up to 2.1 g g−1, which represents the highest value among dye adsorptions reported so far. The adsorption mechanism was investigated by FTIR analysis, solution pH effect, and some control experiments. It was concluded that the adsorption process was based on the Eschenmoser salt assisted 1,4-Michael addition reaction between the ortho position of the catechol phenolic hydroxyl group of PD and Eschenmoser groups in the dyes. The adsorption isotherms were explored according to the Langmuir and Freundlich models respectively, and matched well with the Langmuir model. The thermodynamic parameters (ΔH, ΔG, ΔS, and E) were also calculated, which suggested an exothermic and spontaneous adsorption process. In addition, PD/GO exhibited an improved adsorption capacity for heavy metal ions (53.6 mg g−1 for Pb2+, 24.4 mg g−1 for Cu2+, 33.3 mg g−1 for Cd2+, and 15.2 mg g−1 for Hg2+, respectively) than pure PD and GO. Our results indicate the effectiveness of the synergistic effect of individual components on designing new functional composites with high performance.
Co-reporter:Zheng Gong Wang, Xia Liu, Dong Wang and Jian Jin
Polymer Chemistry 2014 vol. 5(Issue 8) pp:2793-2800
Publication Date(Web):02 Jan 2014
DOI:10.1039/C3PY01608K
“Polymers of intrinsic microporosity” (PIMs) have recently received considerable attention as powerful and promising membrane materials for gas separation, especially for CO2 separation. In this work, a new type of PIM copolymer derived from 2,3,8,9-tetrahydroxy-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine (THTB) and 5,5′,6,6′-tetrahydroxy-3,3′,3′,3-tetramethylspirobisindane (TTSBI) copolymerized with 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN) was synthesized and their properties for CO2 separation were investigated. The molecular structures of the copolymers were characterized by 1H NMR and the molecular weights were determined by GPC. Gas transportation measurements demonstrated that the TB-based copolymers exhibit an improved selective capacity for the separation of CO2/N2, CO2/CH4 and O2/N2, while showing a small decrease of permeability. A detailed investigation on the effect of TB on the performance of the copolymers was undertaken by wide-angle X-ray diffraction analysis, BET and fractional free volume measurements, and molecular modeling analysis. It was concluded that the introduction of TB units in the copolymers leads to more efficient chain stacking and gives the copolymers a smaller pore width distribution as compared to the homopolymer derived only from TTSBI and TFTPN (referred as PIM-1). As a consequence, the introduction of TB enhanced the CO2 selectivity, owing to the increase of CO2 solubility when passing through the copolymer membranes.
Co-reporter:Zhenggong Wang, Dong Wang, Feng Zhang, and Jian Jin
ACS Macro Letters 2014 Volume 3(Issue 7) pp:597
Publication Date(Web):June 10, 2014
DOI:10.1021/mz500184z
It is a great challenge for polyimide to increase its permeability and at the same time to maintain its high selectivity. In this work, Tröger’s Base (TB)-based polyimides through polymerizing Tröger’s Base diamines with two kinds of anhydrides were successfully synthesized to enhance the permeability of polyimides for gas separation. The TB-polyimide membranes exhibited greatly improved gas separation performance for H2/CH4, H2/N2, He/CH4, and CO2/CH4 gas pairs, among which the separation performance of 6-FDA-based TB-polyimides approaches or slightly exceeds the 2008 Robeson upper bound. Our results revealed that the TB unit with rigid and in-built amine structure plays an important role for increasing the permeability of polyimides and simultaneously maintaining high selectivity. In addition, the TB-based polyimide membranes exhibited extremely high solubility selectivity for the CO2/N2 gas pair up to 62.7 due to a strong affinity between CO2 and nitrogen atoms of tertiary amine in TB.
Co-reporter:Haili Qin;Dong Wang;Xiong Xiong
Macromolecular Rapid Communications 2014 Volume 35( Issue 11) pp:1055-1060
Publication Date(Web):
DOI:10.1002/marc.201400047
Co-reporter:Wenbin Zhang;Yuzhang Zhu;Xia Liu;Dr. Dong Wang; Jingye Li; Lei Jiang; Jian Jin
Angewandte Chemie International Edition 2014 Volume 53( Issue 3) pp:856-860
Publication Date(Web):
DOI:10.1002/anie.201308183
Abstract
Conventional polymer membranes suffer from low flux and serious fouling when used for treating emulsified oil/water mixtures. Reported herein is the fabrication of a novel superhydrophilic and underwater superoleophobic poly(acrylic acid)-grafted PVDF filtration membrane using a salt-induced phase-inversion approach. A hierarchical micro/nanoscale structure is constructed on the membrane surface and endows it with a superhydrophilic/underwater superoleophobic property. The membrane separates both surfactant-free and surfactant-stabilized oil-in-water emulsions under either a small applied pressure (<0.3 bar) or gravity, with high separation efficiency and high flux, which is one to two orders of magnitude higher than those of commercial filtration membranes having a similar permeation property. The membrane exhibits an excellent antifouling property and is easily recycled for long-term use. The outstanding performance of the membrane and the efficient, energy and cost-effective preparation process highlight its potential for practical applications.
Co-reporter:Wenbin Zhang;Yuzhang Zhu;Xia Liu;Dr. Dong Wang; Jingye Li; Lei Jiang; Jian Jin
Angewandte Chemie 2014 Volume 126( Issue 3) pp:875-879
Publication Date(Web):
DOI:10.1002/ange.201308183
Abstract
Conventional polymer membranes suffer from low flux and serious fouling when used for treating emulsified oil/water mixtures. Reported herein is the fabrication of a novel superhydrophilic and underwater superoleophobic poly(acrylic acid)-grafted PVDF filtration membrane using a salt-induced phase-inversion approach. A hierarchical micro/nanoscale structure is constructed on the membrane surface and endows it with a superhydrophilic/underwater superoleophobic property. The membrane separates both surfactant-free and surfactant-stabilized oil-in-water emulsions under either a small applied pressure (<0.3 bar) or gravity, with high separation efficiency and high flux, which is one to two orders of magnitude higher than those of commercial filtration membranes having a similar permeation property. The membrane exhibits an excellent antifouling property and is easily recycled for long-term use. The outstanding performance of the membrane and the efficient, energy and cost-effective preparation process highlight its potential for practical applications.
Co-reporter:Lei Wang, Chong Lin, Fengxing Zhang, and Jian Jin
ACS Nano 2014 Volume 8(Issue 4) pp:3724
Publication Date(Web):March 6, 2014
DOI:10.1021/nn500386u
It is known that Co(OH)2 can be crystallized into a layered structure with two polymorphs: α and β. The single-layer α-Co(OH)2 nanosheet has been prepared by exfoliating directly α phase layered Co(OH)2. However, due to theoretical barriers, a single-layer β-Co(OH)2 nanosheet has not been achieved so far. In this article, phase transformation during exfoliation of layered Co(OH)2 from α to β is observed and a single-layer β-Co(OH)2 nanosheet with a thickness of ∼1.1 nm is prepared through phase transition of layered α-Co(OH)2 nanocones in a mild wet chemical process for the first time, with a nearly 100% yield. The as-prepared single-layer β-Co(OH)2 nanosheets are assembled with graphene oxide to form an all-two-dimensional materials-based composite for use as an electrode for the pseudocapacitor. The reduced graphene oxide/β-Co(OH)2 composite exhibits a high specific capacitance up to 2080 F/g scaled to the total mass of the electrode or 3355 F/g scaled to the active mass of β-Co(OH)2 nanosheets at the current density of 1 A/g. The electrode also demonstrates the excellent rate performance and long cycle life.Keywords: pseudocapacitors; single-layer β-Co(OH)2 nanosheet; two-dimensional materials
Co-reporter:Shou Jian Gao, Zhun Shi, Wen Bin Zhang, Feng Zhang, and Jian Jin
ACS Nano 2014 Volume 8(Issue 6) pp:6344
Publication Date(Web):May 28, 2014
DOI:10.1021/nn501851a
A SWCNT/TiO2 nanocomposite ultrathin film that has superhydrophilic and underwater superoleophobic properties after UV-light irradiation is successfully prepared by coating TiO2 via the sol–gel process onto an SWCNT ultrathin network film. The robust and flexible SWCNT/TiO2 nanocomposite films with a thickness and pore size of tens of nanometers can separate both surfactant-free and surfactant-stabilized oil-in-water emulsions in an ultrafast manner with fluxes up to 30 000 L m–2 h–1 bar–1, which is 2 orders of magnitude higher than commercial filtration membranes with similar separation performance, and with high separation efficiency. Most importantly, the films exhibit excellent antifouling and self-cleaning performance during multiple cycles with the aid of the photocatalytic property of TiO2 nanoparticles. This work provides a route for designing ultrathin and superwetting films for effective separation of oil-in-water emulsions. The SWCNT/TiO2 ultrathin film is potentially useful in treating emulsified wastewater produced in industry and daily life and for purification of crude oil and fuel.Keywords: emulsion separation; superhydrophilic and underwater superoleophobic; SWCNT/TiO2 nanocomposite film; ultrathin film
Co-reporter:Zhenggong Wang, Dong Wang, and Jian Jin
Macromolecules 2014 Volume 47(Issue 21) pp:7477-7483
Publication Date(Web):October 30, 2014
DOI:10.1021/ma5017506
Polyimides of intrinsic microporosity are important polymers for gas separation. Achieving polyimides with high permeability and high selectivity relies on rationally designing their chain structure. In this work, new ladder-like diamines, Tröger’s Base (TB) derived diamines, are designed, and two microporous polyimides are constructed by polymerizing TB-derived diamines and spirobisindane based dianhydride, aiming at enhancing the stiffness of the whole backbone and thus achieving improved performance by taking advantage of the stiffness of both diamines and dianhydride. The two polyimides present excellent separation performance, surpassing the 2008 Robeson upper bound for gas pairs of H2/N2 and O2/N2 and approach the 2008 Robeson upper bound for gas pairs H2/CH4 and CO2/CH4. Our results show that the designed polyimides have great potential for application especially for oxygen (O2/N2) and hydrogen (such as H2/N2 and H2/CH4) related separation.
Co-reporter:Wenbin Zhang;Zhun Shi;Feng Zhang;Xia Liu;Lei Jiang
Advanced Materials 2013 Volume 25( Issue 14) pp:2071-2076
Publication Date(Web):
DOI:10.1002/adma.201204520
Co-reporter:Zhun Shi;Wenbin Zhang;Feng Zhang;Xia Liu;Dong Wang;Lei Jiang
Advanced Materials 2013 Volume 25( Issue 17) pp:2422-2427
Publication Date(Web):
DOI:10.1002/adma.201204873
Co-reporter:Feng Zhang;Wen Bin Zhang;Zhun Shi;Dong Wang;Lei Jiang
Advanced Materials 2013 Volume 25( Issue 30) pp:4192-4198
Publication Date(Web):
DOI:10.1002/adma.201301480
Co-reporter:Lei Wang, Dong Wang, Fengxing Zhang, and Jian Jin
Nano Letters 2013 Volume 13(Issue 9) pp:4206-4211
Publication Date(Web):August 5, 2013
DOI:10.1021/nl4018868
To date, most of the research on electrodes for energy storage has been focused on the active material itself. It is clear that investigating isolated active materials is no longer sufficient to solve all kinds of technological challenges for the development of modern battery infrastructure. From the interface chemistry point of view, a system-level strategy of designing polydopamine coated reduced graphene oxide/sulfur composite cathodes aimed at enhancing cyclic performance was reported in this work. As a soft buffer layer, the polydopamine shell was used to accommodate the volume expansion of S and avoid the leakage of polysulfide during cycling. A cross-link reaction between polydopamine buffer and poly(acrylic acid) binder was further designed to improve the strength of the entire electrode. As a result, the electrode demonstrated excellent cyclic performance with a discharge capacity of 728 mAh/g after 500 cycles at the current density of 0.5 A/g (a very small capacity loss of 0.41 mAh/g per cycle). Most importantly, 530 mAh/g was obtained even at a higher current density of 1 A/g after 800 cycles. Our results indicate the importance of chemically designing interfaces in the whole electrode system on achieving improved performance of electrodes of rechargeable lithium ion batteries.
Co-reporter:Lei Wang, Zhihui Dong, Dong Wang, Fengxing Zhang, and Jian Jin
Nano Letters 2013 Volume 13(Issue 12) pp:6244-6250
Publication Date(Web):November 8, 2013
DOI:10.1021/nl403715h
High-capacity electrochemical active material-based electrodes for lithium ion batteries (LIBs), such as sulfur (S), always face the collapse of the electrode due to the big volume change during insertion of the lithium (Li) ion and therefore shorten the cycle life of the cells. Herein, a series of design from the viewpoint of both individual components and the entire cathode in lithium–sulfur (Li–S) cell was introduced aiming at addressing the issues of poor conductivity, leakage of intermediate polysulphides, and large volumetric expansion upon insertion of the Li ion. In the designed electrode, polydopamine (PD)-coated S nanosheets (NSs) were used as active materials, carboxylic acid functionalized multiwall carbon nanotube (MWCNT-COOH) as conductive additives, and poly(acrylic acid) (PAA) as binders. Far different from the traditional hydrogen bond and/or van der Waals force linked electrodes, stronger covalent bonds formed by cross-linking of PD/MWCNT-COOH and PD/PAA into amide bonds, respectively, were built throughout the whole electrode to firmly integrate all of the individual components in the electrode together. As a result, the cathode demonstrated excellent cyclic performance with a charge capacity of 640 mAh/g after 500 cycles at a current density of 1 A/g. Besides, the charge capacity decay after 500 cycles is as small as 0.021% per cycle, which represents the best capacity retention so far.
Co-reporter:Lei Wang, Dong Wang, Zhihui Dong, Fengxing Zhang, and Jian Jin
Nano Letters 2013 Volume 13(Issue 4) pp:1711-1716
Publication Date(Web):March 11, 2013
DOI:10.1021/nl400269d
From the whole anode electrode of view, we report in this work a system-level strategy of fabrication of reduced graphene oxide (RGO)/SnO2 composite-based anode for lithium ion battery (LIB) to enhance the capacity and cyclic performance of SnO2-based electrode materials. RGO/SnO2 composite was first coated by a nanothick polydopamine (PD) layer and the PD-coated RGO/SnO2 composite was then cross-linked with poly(acrylic acid) (PAA) that was used as a binder to accomplish a whole anode electrode. The cross-link reaction between PAA and PD produced a robust network in the anode system to stabilize the whole anode during cycling. As a result, the designed anode exhibits an outstanding energy capacity up to 718 mAh/g at current density of 100 mA/g after 200 cycles and a good rate performance of 811, 700, 641, and 512 mAh/g at current density of 100, 250, 500, and 1000 mA/g, respectively. Fourier transform IR spectra confirm the formation of cross-link reaction and the stability of the robust network after long-term cycling. Our results indicate the importance of designing interfaces in anode system on achieving improved performance of electrode of LIBs.
Co-reporter:Hai Li Qin ; Dong Wang ; Zeng Li Huang ; Dong Min Wu ; Zhi Cong Zeng ; Bin Ren ; Ke Xu
Journal of the American Chemical Society 2013 Volume 135(Issue 34) pp:12544-12547
Publication Date(Web):August 13, 2013
DOI:10.1021/ja406107u
Thickness-controlled synthesis of nanosheets of nonlayered materials is of scientific significance yet greatly underdeveloped because of the lack of controllable means of inducing anisotropic growth of 2D structures. Here we report a novel 2D template-directed synthesis of ultrathin single-crystalline Au nanosheets with well-tuned thicknesses of several to tens of nanometers, large areas (>100 μm2), and atomically flat surfaces. The 2D template is composed of hundred-nanometer-thick water layers sandwiched by lamellar bilayer membranes of a self-assembled nonionic surfactant, dodecylglyceryl itaconate, which appears as an iridescent solution as a result of Bragg reflection of visible light from the periodic lamellar planes. The large-area, ultrathin single-crystalline Au nanosheets enable the fabrication of plasmonic devices. For the first time, the property of surface plasmon polaritons on a patterned single-crystalline Au nanosheet was investigated, and a long propagation length approaching the theoretical expectation was found.
Co-reporter:Lei Wang;Zhi Hui Dong;Zheng Gong Wang;Feng Xing Zhang
Advanced Functional Materials 2013 Volume 23( Issue 21) pp:2758-2764
Publication Date(Web):
DOI:10.1002/adfm.201202786
Abstract
The effect of space accessible to electrolyte ions on the electrochemical activity is studied for a system of transition-metal hydroxide-based pseudocapacitors. Layered α-Co(OH)2 with various intercalated anions is used as a model material. Three types of layered α-Co(OH)2 with intercalated anions of dodecyl sulfate, benzoate, or nitrate, are prepared by a simple reflux and an anion-exchange process. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations and X-ray diffraction (XRD) data show the formation of layered α-Co(OH)2 nanocones with interlayer spacing between adjacent Co(OH)2 single sheets of 1.6, 0.7, and 0.09 nm, corresponding to the anions as listed above. Electrochemical characterization reveals that interlayer space has a great effect on the electrochemical activity of α-Co(OH)2 nanocones as an electrode material. For the interlayer spacing of 1.6 nm, in the case of dodecyl sulfate-intercalated α-Co(OH)2, the Faradaic reaction takes place more adequately than for benzoate- and nitrate-intercalated α-Co(OH)2. As a result, a higher specific capacitance and better cycling stability is obtained for the dodecyl sulfate-intercalated α-Co(OH)2. The electrochemical activity obviously reduces when the interlayer space decreases to 0.7 nm. Our results suggest the importance of rational designing the interlayer space of layered transition metal hydroxides for high-performance pseudocapacitors.
Co-reporter:Yuzhang Zhu, Feng Zhang, Dong Wang, Xian Feng Pei, Wenbin Zhang and Jian Jin
Journal of Materials Chemistry A 2013 vol. 1(Issue 18) pp:5758-5765
Publication Date(Web):06 Mar 2013
DOI:10.1039/C3TA01598J
Oil–water separation is a worldwide challenge because of increasingly oily wastewater, as well as frequent oil spill accidents. We report in this work the fabrication of a zwitterionic polyelectrolyte brush (poly(3-(N-2-methacryloxyethyl-N,N-dimethyl) ammonatopropanesultone), abbreviated as PMAPS)-grafted poly(vinylidene fluoride) (PMAPS-g-PVDF) membrane via a surface-initiated atom transfer radical polymerization (SI-ATRP) technique for separating oil from water. By tuning polymerization time, a superhydrophilic and underwater superoleophobic PMAPS-g-PVDF membrane was successfully prepared. The membrane can be applied for thoroughly separating dispersed oil from water with ultrahigh separation efficiency >99.999% in terms of rejection coefficient. The oil contents after one-time separation of a selection of oil–water mixtures are all less than 10 ppm and some of them are even lower than 2 ppm. These values are much lower than the standard minimum requirements of the international regulations for wastewater discharging. The oil-adhesion force between an oil droplet and the membrane surface was measured to be less than 1 μN. Due to the ultralow oil adhesion, the membrane exhibits an excellent antifouling property to oil and is easily recyclable.
Co-reporter:Fangping Shen, Dong Wang, Rui Liu, Xianfeng Pei, Ting Zhang and Jian Jin
Nanoscale 2013 vol. 5(Issue 2) pp:537-540
Publication Date(Web):27 Nov 2012
DOI:10.1039/C2NR32752J
Graphene oxide was tailored into GO nanosheets with periodic acid treatment. Interestingly, the latter have a superior sensing performance for the fast and reversible detection of SO2 compared with the former at room temperature. Its sensing mechanism was proposed from the structural changes of the GO nanosheets during the sensing and recovering processes.
Co-reporter:Feng Zhang, Wenbin Zhang, Yang Yu, Bo Deng, Jingye Li, Jian Jin
Journal of Membrane Science 2013 Volume 432() pp:25-32
Publication Date(Web):1 April 2013
DOI:10.1016/j.memsci.2012.12.041
High permeability and antifouling property are important performance of filtration membranes for reaching the requirement of real application. In this work, poly(acrylic acid) grafted PVDF (G-PVDF)/TiO2 nanocomposite hollow fiber ultrafiltration membranes were fabricated by combining tetrabutyl titanate in-situ sol–gel process with liquid-induced phase separation. Energy dispersive X-ray (EDX) and EDX mapping scanning spectra confirmed the formation of TiO2 component and uniformly dispersion of TiO2 nanoparticles in nanocomposite membranes with ultrafine size when the TiO2 content was less than 3 wt%. The effect of TiO2 on the membrane performance was systematically investigated. The G-PVDF/TiO2 nanocomposite membranes exhibited extremely high water permeation, improved antifouling property and rejection efficiency as compared to PVDF and G-PVDF membranes. In case of ∼1 wt% TiO2 content, the water flux of G-PVDF/TiO2 nanocomposite membranes reached 974 L/m2 h under 0.1 MPa, which was more than four times of that of PVDF membranes. Simultaneously, G-PVDF/TiO2 nanocomposite membranes displayed greatly reduced amount of protein adsorption to be 24 μg/cm2, which is a seventh of that of PVDF membranes. Two cycles of flux recovery test also indicated that G-PVDF/TiO2 nanocomposite membranes possessed better antifouling property and stability. More important is that the incorporation of TiO2 nanoparticles did not weaken the mechanical strength of the membranes. The superior performance of our G-PVDF/TiO2 nanocomposite hollow fiber ultrafiltration membranes offers a great potential for practical application.Highlights► Nanocomposite hollow fiber membranes were fabricated by in-situ sol–gel process. ► Poly(acrylic acid) grafted PVDF is used as the polymer matrix. ► SEM and EDX showed the well distribution of TiO2 nanoparticles in the membrane. ► The resulted nanocomposite membranes had extremely high water flux.
Co-reporter:Lei Wang, Dong Wang, Feng-Xing Zhang and Jian Jin
RSC Advances 2013 vol. 3(Issue 5) pp:1307-1310
Publication Date(Web):05 Nov 2012
DOI:10.1039/C2RA22375A
A protein-inspired facile approach to synthesise carbon-coated SnO2 nanocrystals (NCs) is presented. The carbon coating content could be readily tuned by adjusting the pH value of the reaction solution. The obtained carbon-coated SnO2 NCs showed a markedly improved lithium storage ability.
Co-reporter:Zhun Shi, Changsong Liu, Wenhui Lv, Huaibin Shen, Dong Wang, Liwei Chen, Lin Song Li and Jian Jin
Nanoscale 2012 vol. 4(Issue 15) pp:4515-4521
Publication Date(Web):23 May 2012
DOI:10.1039/C2NR30920C
In this work, we described a facile route for the fabrication of free-standing single-walled carbon nanotubes (SWCNT)–CdSe quantum dots (QDs) hybrid ultrathin films and investigated their optoelectronic conversion properties. A free-standing SWCNT film with thickness of ∼36 nm was firstly prepared via vacuum filtration. The film was then immersed into the pre-synthesized oleic acid-capped CdSe QDs (average diameter of 3.5 nm) solution, where CdSe QDs anchored spontaneously onto the surface of SWCNT film to produce SWCNT–CdSe QDs hybrid film. By using pure SWCNT films in different thicknesses as bottom and top electrodes, a flexible all-carbon electrode optoelectronic conversion device with sandwich structure of SWCNT film (thickness of ∼200 nm)/SWCNT–CdSe QDs hybrid film (thickness of ∼36 nm)/SWCNT film (thickness of ∼36 nm) was constructed to generate optoelectronic conversion under illumination of solar-simulated light. Our results demonstrated that the all-carbon electrode structure was effective for charge separation and a sensitive and stable photocurrent signal could be produced in such a device. In addition, our SWCNT–CdSe QDs hybrid film exhibited high flexibility and durability. No clear change in the resistance of the film was detected under bending in various bending angles.
Co-reporter:Yanxiang Li, Guanghui Li, Xuewen Wang, Zhiqiang Zhu, Hongwei Ma, Ting Zhang and Jian Jin
Chemical Communications 2012 vol. 48(Issue 66) pp:8222-8224
Publication Date(Web):28 Jun 2012
DOI:10.1039/C2CC33365A
An ultrasensitive CO2 sensor with a detection limit of 500 ppt was achieved using poly(ionic liquid)-wrapped single-walled carbon nanotubes as sensing materials. The sensor exhibited superior selectivity to CO2 and was resistant to the interference of relative humidity.
Co-reporter:Dong Wang, Lei Wang, Xinyi Dong, Zhun Shi, Jian Jin
Carbon 2012 Volume 50(Issue 6) pp:2147-2154
Publication Date(Web):May 2012
DOI:10.1016/j.carbon.2012.01.021
A method is presented to tailor the lateral size of graphene oxide (GO) in the range of 10–100 nm and simultaneously tailor its edge structure by oxidation with periodic acid in a one-pot process. The obtained GO nanosheets are photoluminescent and exhibit lateral size-dependent behavior. The emission wavelength could be tuned from 550 to 470 nm by decreasing the lateral size. The fluorescence of GO nanosheets shows a sensitive and selective quenching effect to Fe3+ ions, allowing it to be used as a fluorescent probe to detect Fe3+ ions with a detection limit of 1 ppm.
Co-reporter:Xinyi Dong, Lei Wang, Dong Wang, Cheng Li, and Jian Jin
Langmuir 2012 Volume 28(Issue 1) pp:293-298
Publication Date(Web):November 28, 2011
DOI:10.1021/la2038685
Multilayer films of Co–Al layered double hydroxide nanosheets (Co–Al LDH-NS) and graphene oxide (GO) were fabricated through layer-by-layer (LBL) assembly. By using a three-electrode system, the electrochemical performances of the films were investigated to evaluate their potential as electrode materials to be used in flexible supercapacitor devices. The Co–Al LDH-NS/GO multilayer films exhibited a high specific capacitance of 880 F/g and area capacitance of 70 F/m2 under the scan rate of 5 mV/s. And the film exhibited good cycle stability over 2000 cycles. After treating the films at 200 °C in H2 atmosphere, the specific capacitance and area capacitance were largely increased up to 1204 F/g and 90 F/m2 due to partial reduction of GO. A flexible electrode by depositing Co–Al LDH-NS/GO multilayer film onto PET substrate was prepared to show the potential of Co–Al LDH-NS/GO films for flexible energy storage.
Co-reporter:Zhun Shi;Xinjiang Chen;Xuewen Wang;Ting Zhang
Advanced Functional Materials 2011 Volume 21( Issue 22) pp:4358-4363
Publication Date(Web):
DOI:10.1002/adfm.201101298
Abstract
A one-pot and readily practical approach is described for the preparation of superstrong, ultrathin, free-standing single-walled carbon nanotube (SWNT) films. The SWNT films, with controlled thicknesses of tens to hundreds of nanometers, are prepared from commonly commercialized SWNTs via a wet process. The SWNTs could be easily transferred onto any substrates after self-releasing from filter membranes without further treatment. The obtained films exhibit excellent performances with sheet resistance of 223 Ω sq−1 and a transparency of 90% at 550 nm was obtained. Most important is that the as-prepared free-standing SWNT ultrathin films showed extremely high tensile strength up to 850 MPa for only about a 20-nm thick film, which has great significance for practical applications, for example, as flexible electrode materials. The SWNT film is used to construct a capacitive touch-screen prototype, which has a highly sensitive and quick signal touch response.
Co-reporter:Lei Wang, Dong Wang, Xin Yi Dong, Zhi Jun Zhang, Xian Feng Pei, Xin Jiang Chen, Biao Chen and Jian Jin
Chemical Communications 2011 vol. 47(Issue 12) pp:3556-3558
Publication Date(Web):15 Feb 2011
DOI:10.1039/C0CC05420H
An innovative strategy of fabricating electrode material by layered assembling two kinds of one-atom-thick sheets, carboxylated graphene oxide (GO) and Co–Al layered double hydroxide nanosheet (Co–Al LDH-NS) for the application as a pseudocapacitor is reported. The Co–Al LDH-NS/GO composite exhibits good energy storage properties.
Co-reporter:Yanxiang Li, Dong Wang, Xianfeng Pei, Zhun Shi, Lei Wang, Wenbin Zhang and Jian Jin
Soft Matter 2011 vol. 7(Issue 6) pp:2682-2686
Publication Date(Web):20 Jan 2011
DOI:10.1039/C0SM00982B
Novel gel-like poly(ethylene dioxythiophene) (PEDOT) microspheres were fabricated via micelle-mediated polymerization from room temperature ionic liquids (RTILs). The microspheres consist of PEDOT chains as three-dimensional solid networks and a large volume of EDOT as liquid medium span them. Due to synergistic effect of micelles and RTILs, the polymerization rate of PEDOT in the system is slowed down greatly. Gel-like PEDOT microspheres spontaneously grew from several tens of nanometers to centimeter scale and the whole process lasted for several days. Thus, the growth of the microspheres is tracked in situ. The microspheres could release and adsorb EDOT reversibly under certain conditions, indicating a gel-like behavior.
Co-reporter:Haili Qin, Jian Jin, Xinsheng Peng and Izumi Ichinose
Journal of Materials Chemistry A 2010 vol. 20(Issue 5) pp:858-861
Publication Date(Web):04 Dec 2009
DOI:10.1039/B923745N
Mechanical properties of free-standing single layers of Pt nanocrystals with particle diameters of 1.5 nm and 3.0 nm were examined via AFM by fitting force–indentation curves. It showed that the Young's moduli of Pt membranes were in the range of 1–10 GPa and fracture strengths were in the range of 1–30 MPa.
Co-reporter:Dong Wang, Yan-Xiang Li, Zhun Shi, Hai-Li Qin, Lei Wang, Xian-Feng Pei, and Jian Jin
Langmuir 2010 Volume 26(Issue 18) pp:14405-14408
Publication Date(Web):August 23, 2010
DOI:10.1021/la102710h
A novel strategy for the one-pot fabrication of free-standing polypyrrole films is presented in this work. The films are spontaneously formed at an air/ionic liquid interface through interface oxypolymerization. The thicknesses of the films are finely controlled from tens to hundreds of nanometers, and the films are uniform and compact. Asymmetrical films with different smoothness on the two sides of the film are also obtained and exhibit different water wettability. This method is extremely simple and does not need any equipment. It may bring about a general methodology for forming free-standing conducting polymer films.
Co-reporter:Jian Jin, Weifeng Bu and Izumi Ichinose
Langmuir 2010 Volume 26(Issue 13) pp:10506-10512
Publication Date(Web):April 21, 2010
DOI:10.1021/la100523b
Dried foam films (DFFs), which are free-standing reversed bilayers covering the holes of micrometers, are obtained by using several types of surfactants. In this article, we examined the formation of DFFs from a wide range of surfactants, systematically changing the headgroup, the counterion, the length and number of alkyl chains, and so forth. Some DFFs showed thermal stability higher than 150 °C. The interaction among headgroups in each monolayer of DFFs significantly contributed to the high thermal stability. The elastic moduli of DFFs were in the range of 4−42 MPa, as determined by a nanoindentation technique using AFM. A nonionic surfactant (Brij-35) formed stable DFFs only when urea was incorporated to form hydrogen bonds with the ethylene oxide units. The thermal stability of DPC (dodecylphosphocholine) films was increased up to 220 °C by adding Cd2+ because of the formation of a coordination network with the phosphate groups. Then the elastic modulus increased from 15 to 32 MPa. It was also possible to incorporate polyelectrolytes (Na2SiO3 and PAH) and a cadmium polynuclear complex ([Cd10(SCH2CH2OH)16]·(ClO4)4) into the interlayer space of DFFs by tuning the proximal electrostatic interaction with the headgroups of surfactants.
Co-reporter:Lei Wang ; Chong Lin ; Dekang Huang ; Fengxing Zhang ; Mingkui Wang
ACS Applied Materials & Interfaces () pp:
Publication Date(Web):
DOI:10.1021/am5014369
Oxygen electrochemistry has been intensely studied in the pursuit of sustainable and efficient energy conversion and storage solutions. Over the years, developing oxygen electrode catalysts with high activity and low cost remains a great challenge, despite tremendous efforts. Here, NixCo1–x(OH)2 is used as a bifunctional electrocatalyst for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). The effect of its compositions (x = 1, 0.55, 0) and morphologies (including both multilayer and single-layer NixCo1–x(OH)2) on catalytic activity is studied systematically in order to optimize the oxygen-electrochemical performance of 3d-M (M = Ni and Co) metal hydroxides. Our results show that the compositions of NixCo1–x(OH)2 has a great influence on overpotentials by comparing multilayer Co(OH)2, Ni0.55Co0.45(OH)2, and Ni(OH)2 for OER. Multilayer Ni(OH)2 exhibits the lowest overpotential of 324 mV at the current density of 5 mA/cm2. Moreover, the overpotential could be greatly lowered by using single-layer NixCo1–x(OH)2. Single-layer Ni(OH)2 nanosheet manifests 71 mV overpotential decrease (5 mA/cm2) and a factor of 14 turnover frequency increase as compared to multilayer Co(OH)2 for OER. As for ORR, multilayer Co(OH)2 shows the best activity among multilayer NixCo1–x(OH)2. Similar to OER, single-layer NixCo1–x(OH)2 demonstrates enhanced ORR activity over multilayer NixCo1–x(OH)2. Single-layer Co(OH)2 exhibits the best catalytic activity and 3.7 electrons are transferred during oxygen reduction process. The successful identification of the composition and morphology effect of 3d metal hydroxides on electrocatalytic performance provides the foundation for rational design of active sites for high-performance catalyst for both OER and ORR.
Co-reporter:Zhenggong Wang, Huiting Ren, Shenxiang Zhang, Feng Zhang and Jian Jin
Journal of Materials Chemistry A 2017 - vol. 5(Issue 22) pp:NaN10977-10977
Publication Date(Web):2017/04/24
DOI:10.1039/C7TA01773A
Mixed matrix membranes (MMMs), i.e., organic–inorganic hybrid membranes, are one of the most promising membranes for overcoming the performance limitations of conventional polymer membranes in gas separation. Polymers of intrinsic microporosity (PIMs) have received considerable research interest due to their high permeability arising from their rigid and contorted chain structure. However, interfacial issues in PIM-based hybrid membranes are serious due to the low mobility and flexibility of their polymer chains. We present in this work the fabrication of a PIM-based hybrid membrane using amidoxime-functionalized PIM-1 as the polymer matrix and an amine-functionalized metal–organic framework (MOF), NH2-UiO-66, as the inorganic filler. In the hybrid membrane, amidoxime and amine groups tend to form hydrogen bonds, creating a hydrogen bond network between the two phases. Therefore, a nearly ideal and defect-free interface is constructed. The well-designed hybrid membrane exhibits excellent separation performance, especially for CO2 capture, with a CO2 permeability as high as 8425 barrer and CO2/N2 and CO2/CH4 gas pair selectivities of up to 27.5 and 23.0, respectively. The overall separation performance of the hybrid membrane for CO2/N2 and CO2/CH4 surpasses the 2008-updated Robeson upper bound and is outstanding compared with those of existing mixed matrix membranes.
Co-reporter:Shou Jian Gao, Yu Zhang Zhu, Feng Zhang and Jian Jin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 6) pp:NaN2902-2902
Publication Date(Web):2014/12/15
DOI:10.1039/C4TA05624H
Functional membranes with a superwetting surface property have been extensively explored to achieve oil–water separation. Here, single-walled carbon nanotube/polydopamine/polyethyleneimine (SWCNT/PD/PEI) composite ultrathin films which have superhydrophilic and underwater superoleophobic properties were successfully prepared and used for the ultrafast separation of surfactant-stabilized oil-in-water nanoemulsions containing oil droplets of tens of nanometers. A SWCNT/PD/PEI composite film with an effective pore size of ∼10 nm and a thickness of ∼160 nm can effectively separate oil-in-water nanoemulsions in an ultrafast manner with fluxes up to ∼6000 L m−2 h−1 bar−1, which is 10-fold higher than traditional ultrafiltration membranes with a similar rejection property. Meanwhile, this film exhibits excellent pH-stability and antifouling property. This work points a direction for designing and fabricating ultrathin and superwetting films for the effective separation of oil-in-water nanoemulsions or nano-sized oils which are hard to separate by traditional methods. The SWCNT/PD/PEI ultrathin film holds promising potential for purifying emulsified wastewater from industries and daily life and for drinking water treatment.
Co-reporter:Liang Hu, Shoujian Gao, Yuzhang Zhu, Feng Zhang, Lei Jiang and Jian Jin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 46) pp:NaN23482-23482
Publication Date(Web):2015/10/14
DOI:10.1039/C5TA03975D
Superwetting membranes offer a good platform for oil/water separation, but the generation of responsive membranes for on-demand oil/water emulsion separation with both high permeation flux and selectivity is still a challenge. Herein, bilayer membranes that feature asymmetric wettability across the membrane thickness are constructed, simply by depositing a thin layer of polydopamine-coated single-walled carbon nanotubes (SWCNTs) and subsequently coating with a SWCNT layer. When a low applied pressure difference across the membrane, Papplied, is utilized, the hydrophobic–superoleophilic surface is critical for the separation of surfactant-stabilized water-in-oil emulsions. Triggered by an intensive Papplied, surfactant-stabilized oil-in-water emulsions can also be fully separated by a synergistic effect of dual layers. Such ultrathin bilayer membranes exhibit ultrahigh permeation flux and separation efficiency with excellent antifouling for both water-in-oil and oil-in-water emulsion separation in a single-unit, which is readily achieved by the modulation of Papplied. Therefore, we envision that our bilayer membranes show great potential in oil/water emulsion separation.
Co-reporter:Haili Qin, Jian Jin, Xinsheng Peng and Izumi Ichinose
Journal of Materials Chemistry A 2010 - vol. 20(Issue 5) pp:NaN861-861
Publication Date(Web):2009/12/04
DOI:10.1039/B923745N
Mechanical properties of free-standing single layers of Pt nanocrystals with particle diameters of 1.5 nm and 3.0 nm were examined via AFM by fitting force–indentation curves. It showed that the Young's moduli of Pt membranes were in the range of 1–10 GPa and fracture strengths were in the range of 1–30 MPa.
Co-reporter:Yuzhang Zhu, Feng Zhang, Dong Wang, Xian Feng Pei, Wenbin Zhang and Jian Jin
Journal of Materials Chemistry A 2013 - vol. 1(Issue 18) pp:NaN5765-5765
Publication Date(Web):2013/03/06
DOI:10.1039/C3TA01598J
Oil–water separation is a worldwide challenge because of increasingly oily wastewater, as well as frequent oil spill accidents. We report in this work the fabrication of a zwitterionic polyelectrolyte brush (poly(3-(N-2-methacryloxyethyl-N,N-dimethyl) ammonatopropanesultone), abbreviated as PMAPS)-grafted poly(vinylidene fluoride) (PMAPS-g-PVDF) membrane via a surface-initiated atom transfer radical polymerization (SI-ATRP) technique for separating oil from water. By tuning polymerization time, a superhydrophilic and underwater superoleophobic PMAPS-g-PVDF membrane was successfully prepared. The membrane can be applied for thoroughly separating dispersed oil from water with ultrahigh separation efficiency >99.999% in terms of rejection coefficient. The oil contents after one-time separation of a selection of oil–water mixtures are all less than 10 ppm and some of them are even lower than 2 ppm. These values are much lower than the standard minimum requirements of the international regulations for wastewater discharging. The oil-adhesion force between an oil droplet and the membrane surface was measured to be less than 1 μN. Due to the ultralow oil adhesion, the membrane exhibits an excellent antifouling property to oil and is easily recyclable.
Co-reporter:Zhihui Dong, Dong Wang, Xia Liu, Xianfeng Pei, Liwei Chen and Jian Jin
Journal of Materials Chemistry A 2014 - vol. 2(Issue 14) pp:NaN5040-5040
Publication Date(Web):2014/01/20
DOI:10.1039/C3TA14751G
By utilizing the synergistic effect of poly-dopamine (PD) with functional groups and graphene oxide (GO) with a high surface area, a series of sub-nano thick PD layer coated GO (PD/GO) composites were fabricated by a well-controlled self-polymerization of dopamine via catechol chemistry and used for effectively decontaminating wastewater. The obtained PD/GO could selectively adsorb the dyes containing an Eschenmoser structure and showed an extremely high adsorption capacity up to 2.1 g g−1, which represents the highest value among dye adsorptions reported so far. The adsorption mechanism was investigated by FTIR analysis, solution pH effect, and some control experiments. It was concluded that the adsorption process was based on the Eschenmoser salt assisted 1,4-Michael addition reaction between the ortho position of the catechol phenolic hydroxyl group of PD and Eschenmoser groups in the dyes. The adsorption isotherms were explored according to the Langmuir and Freundlich models respectively, and matched well with the Langmuir model. The thermodynamic parameters (ΔH, ΔG, ΔS, and E) were also calculated, which suggested an exothermic and spontaneous adsorption process. In addition, PD/GO exhibited an improved adsorption capacity for heavy metal ions (53.6 mg g−1 for Pb2+, 24.4 mg g−1 for Cu2+, 33.3 mg g−1 for Cd2+, and 15.2 mg g−1 for Hg2+, respectively) than pure PD and GO. Our results indicate the effectiveness of the synergistic effect of individual components on designing new functional composites with high performance.
Co-reporter:Shou Jian Gao, Haili Qin, Pingping Liu and Jian Jin
Journal of Materials Chemistry A 2015 - vol. 3(Issue 12) pp:NaN6654-6654
Publication Date(Web):2015/02/16
DOI:10.1039/C5TA00366K
Laminar separation membranes fabricated with two-dimensional nanomaterials have been extensively explored to achieve the separation of molecules and water purification. Herein, single-walled carbon nanotube (SWCNT)-intercalated graphene oxide (GO) ultrathin laminar films are successfully prepared and used for the separation of molecules with sizes greater than 1.8 nm. Nanochannels created by the intercalation of SWCNT into GO layers greatly improve water permeation compared with pure GO films without sacrificing the rejection of nanometer-scale particles and molecules. A SWCNT-intercalated GO film with a thickness of 40 nm can effectively separate Bovine Serum Albumin, cytochrome c, Coomassie Brilliant Blue and Rhodamine B with fluxes of 660–720 L m−2 h−1 bar−1, which are about 10-fold higher than the fluxes of traditional nanofiltration membranes with similar rejection properties. The films also exhibit high separation efficiencies of 97.4% to 98.7%. Moreover, the SWCNT-intercalated GO films exhibit excellent pH-stabilities when used in extreme pH conditions, and it is superior to most of the ceramic- and polymer-based membranes. The SWCNT-intercalated GO films have a promising potential to be used as advanced separation membranes for water purification and chemical refinement.
Co-reporter:Chong Lin, Weikun Zhang, Lei Wang, Zhenggong Wang, Wen Zhao, Wenhui Duan, Zhigang Zhao, Bin Liu and Jian Jin
Journal of Materials Chemistry A 2016 - vol. 4(Issue 16) pp:NaN5998-5998
Publication Date(Web):2016/03/21
DOI:10.1039/C5TA10307J
We report in this work a new type composite separator that contains a conductive few-layered Ti3C2 nanosheet and a glass fiber (GF) membrane for lithium–sulfur (Li–S) batteries. Using commercial bulk S (particle size 2–10 μm) as the cathode directly, the Li–S battery delivers an initial discharge capacity of 820 mA h g−1 at a current density of 0.5 A g−1 and a discharge capacity of 721 mA h g−1 after 100 cycles.
Co-reporter:Lei Wang, Dong Wang, Xin Yi Dong, Zhi Jun Zhang, Xian Feng Pei, Xin Jiang Chen, Biao Chen and Jian Jin
Chemical Communications 2011 - vol. 47(Issue 12) pp:NaN3558-3558
Publication Date(Web):2011/02/15
DOI:10.1039/C0CC05420H
An innovative strategy of fabricating electrode material by layered assembling two kinds of one-atom-thick sheets, carboxylated graphene oxide (GO) and Co–Al layered double hydroxide nanosheet (Co–Al LDH-NS) for the application as a pseudocapacitor is reported. The Co–Al LDH-NS/GO composite exhibits good energy storage properties.
Co-reporter:Yanxiang Li, Guanghui Li, Xuewen Wang, Zhiqiang Zhu, Hongwei Ma, Ting Zhang and Jian Jin
Chemical Communications 2012 - vol. 48(Issue 66) pp:NaN8224-8224
Publication Date(Web):2012/06/28
DOI:10.1039/C2CC33365A
An ultrasensitive CO2 sensor with a detection limit of 500 ppt was achieved using poly(ionic liquid)-wrapped single-walled carbon nanotubes as sensing materials. The sensor exhibited superior selectivity to CO2 and was resistant to the interference of relative humidity.
Co-reporter:Haili Qin, Xiong Xiong, Dongmin Wu, Feng Zhang, Dong Wang, Xia Liu, Wensheng Yang and Jian Jin
Chemical Communications 2015 - vol. 51(Issue 10) pp:NaN1960-1960
Publication Date(Web):2014/12/15
DOI:10.1039/C4CC09370D
A facile strategy for the fabrication of ultralarge (edge length >50 μm), single-crystalline Ag nanomembranes is reported in this work. The Ag nanomembrane with an atomically smooth surface demonstrates a much longer surface plasmonic propagation length as compared to vacuum-deposited polycrystalline Ag film, representing superior plasmonic properties.
Co-reporter:Shenxiang Zhang, Zhenggong Wang, Huiting Ren, Feng Zhang and Jian Jin
Journal of Materials Chemistry A 2017 - vol. 5(Issue 5) pp:NaN1966-1966
Publication Date(Web):2017/01/06
DOI:10.1039/C6TA09570D
An ultrathin and continuous ZIF-8 membrane as thin as ∼550 nm was fabricated via a spatially confined contra-diffusion process, in which a nanoporous network film is utilized as an interlayer mediator to control the nucleation and growth of ZIF-8 crystals. The membrane exhibits a high H2 permeance up to 6.31 × 10−7 mol m−2 s−1 pa−1 and simultaneously maintains a high ideal selectivity of 43 for H2/CO2.
Co-reporter:Wenbin Zhang, Liang Hu, Hanmei Chen, Shoujian Gao, Xiangcheng Zhang and Jian Jin
Journal of Materials Chemistry A 2017 - vol. 5(Issue 25) pp:NaN4882-4882
Publication Date(Web):2017/05/09
DOI:10.1039/C7TB00644F
Separation of plasma from whole blood is requisite for the accurate measurement of glucose levels. From the wettability point of view, in this study, we report the fabrication of a mineralized Janus membrane with an asymmetric wetting property; this membrane can transport fast microliter-quantity blood and separate out the red blood cells. The membrane is composed of a hydroxyapatite (HAP)-mineralized polyvinylidene fluoride (PVDF) membrane prepared via an interface diffusion-controlled chemical precipitation method. Due to gradient distribution of the HAP nanocrystals across the PVDF membrane, the composite membrane exhibits an asymmetric wetting property where a tiny whole blood droplet (13 μL) can spontaneously permeate across the membrane within 20 s and red blood cells in the whole blood are successfully blocked by the membrane. The membrane is then integrated into blood glucometers for accurate measurements of the glucose levels. The results show that the porous membrane can successfully prevent red blood cells in whole blood from entering the enzyme layer; moreover, the negative effect of hematocrit levels on the blood glucose measurements is effectively minimized and an obviously high and stable glucose current signal is achieved.
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