Co-reporter:Caifu Dong
ACS Applied Materials & Interfaces March 1, 2017 Volume 9(Issue 8) pp:7160-7168
Publication Date(Web):February 6, 2017
DOI:10.1021/acsami.6b15757
Two multifunctional metal–organic frameworks (MOFs) with the same coordination mode, [Co(L)(H2O)]n·2nH2O [defined as “Co(L) MOF”] and [Cd(L)(H2O)]n·2nH2O [defined as “Cd(L) MOF”] (L = 5-aminoisophthalic acid) have been fabricated via a simple and versatile scalable solvothermal approach at 85 °C for 24 h. The relationship between the structure of the electrode materials (especially the coordination water and different metal ions) and the electrochemical properties of MOFs have been investigated for the first time. And then the possible electrochemical mechanisms of the electrodes have been studied and proposed. In addition, MOFs/RGO hybrid materials were prepared via ball milling, which demonstrated better electrochemical performances than those of individual Co(L) MOF and Cd(L) MOF. For example, when Co(L) MOF/RGO was applied as anode for sodium ion batteries (SIBs), it retained 206 mA h g–1 after 330 cycles at 500 mA g–1 and 1185 mA h g–1 could be obtained after 50 cycles at 100 mA g–1 for lithium-ion batteries (LIBs). The high-discharge capacity, excellent cyclic stability combined with the facile synthesis procedure enable Co(L) MOF- and Cd(L) MOF-based materials to be prospective anode materials for SIBs and LIBs.Keywords: anode; lithium-ion batteries; metal−organic frameworks (MOFs); sodium ion batteries; stable;
Co-reporter:Ling Zhou, Lishan Yang, Li Shao, Bo ChenFanhui Meng, Yitai Qian, Liqiang Xu
Inorganic Chemistry 2017 Volume 56(Issue 5) pp:
Publication Date(Web):February 20, 2017
DOI:10.1021/acs.inorgchem.6b02501
Metal boride, carbide, and nitride materials are useful owing to their wide variety of interesting chemical and physical properties. However, the synthesis of these materials with nano or mesoscale sizes is challenging due to the usually required high temperatures and long reaction durations. To our knowledge, the exploration of a number of simultaneous chemical reactions through rapid synthesis still remains a great challenge. In this study, a general route for the reduction and transformation of metal oxides into related metal boride (TiB2, MoB2, DyB4, ErB4, YB4, LaB6, CeB6, SmB6, EuB6), carbide (SiC, TiC, VC, WC, W2C, ZrC, MoC, NbC), and nitride (TiN, VN, BN, AlN, CrN, MgSiN2) nanocrystals were achieved at 150 °C. Here, the exothermic reaction of metal magnesium hydrolysis is utilized to assist the reaction in sealed stainless steel autoclaves. In situ temperature monitoring showed that the inside temperature increased quickly from 139 to 902 °C at the initial stage. The obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), and high-resolution TEM techniques. The low reaction temperature and cheap raw materials make it possible for large-scale synthesis of those nanomaterials.
Co-reporter:Xiaoxia Chen;Zhi Wang;Ranran Zhang;Di Sun
Chemical Communications 2017 vol. 53(Issue 76) pp:10560-10563
Publication Date(Web):2017/09/21
DOI:10.1039/C7CC05741E
The proof-of-principle of an unusual fused γ-[Mo8O26]4− chain as an inorganic ligand is presented for the first time. By sharing two Mo–O edges, the γ-[Mo8O26]4− subunits are propagated into a one-dimensional (1D) zig-zag chain, which acts as a purely inorganic ligand binding octahedral Co(II) centers into a two-dimensional (2D) [CoMo8O26]∞ sheet. This material exhibits high initial reversible specific capacity and stable reversible capacity when applied as an anode for lithium-ion batteries (LIBs).
Co-reporter:Xuan Hou;Chuanchuan Li;Huayun Xu
Nano Research 2017 Volume 10( Issue 10) pp:3585-3595
Publication Date(Web):23 June 2017
DOI:10.1007/s12274-017-1569-4
NaFeTiO4 nanorods of high yields (with diameters in the range of 30–50 nm and lengths of up to 1–5 μm) were synthesized by a facile sol–gel method and were utilized as an anode material for sodium-ion batteries for the first time. The obtained NaFeTiO4 nanorods exhibit a high initial discharge capacity of 294 mA·h·g−1 at 0.2 C (1 C = 177 mA·g–1), and remain at 115 mA·h·g–1 after 50 cycles. Furthermore, multi-walled carbon nanotubes (MWCNTs) were mechanically milled with the pristine material to obtain NaFeTiO4/MWCNTs. The NaFeTiO4/ MWCNTs electrode exhibits a significantly improved electrochemical performance with a stable discharge capacity of 150 mA·h·g–1 at 0.2 C after 50 cycles, and remains at 125 mA·h·g–1 at 0.5 C after 420 cycles. The NaFeTiO4/MWCNTs//Na3V2(PO4)3/C full cell was assembled for the first time; it displays a discharge capacity of 70 mA·h·g−1 after 50 cycles at 0.05 C, indicating its excellent performances. X-ray photoelectron spectroscopy, ex situ X-ray diffraction, and Raman measurements were performed to investigate the initial electrochemical mechanisms of the obtained NaFeTiO4/MWCNTs.
Co-reporter:Aihua Li, Liqiang Xu, Chang Ming Li and Yitai Qian
Journal of Materials Chemistry A 2016 vol. 4(Issue 15) pp:5489-5494
Publication Date(Web):10 Mar 2016
DOI:10.1039/C6TA01624C
Mesh-like LiZnBO3/C composite was synthesized via a facile polymer pyrolysis method for use as an anode in lithium ion batteries (LIBs), demonstrating high initial capacity (860 mA h g−1) and excellent cycle stability (559 mA h g−1 after 600 cycles at 500 mA g−1 with a capacity retention of 94.47%). Ex situ XRD tests indicate a mixed intercalation–conversion–alloy lithium storage mechanism in the first discharge/charge process of the composite. In addition, the LiZnBO3/C anode was coupled with a commercial LiCoO2 cathode in a full cell, which presented an initial reversible capacity of 658 mA h g−1 at 100 mA g−1 and a capacity of 603 mA h g−1 after 400 cycles with average 0.02% fading in each cycle, which greatly outperforms previously reported compounds; this could be attributed to the unique mesh-like morphology of the composite, which enables high mass transport rate and good conductivity, and the coexistence of LiZnBO3–ZnO–Zn composites that produce a synergistic effect for fast kinetics. This study holds great promise for LIBs with high capacity and good stability.
Co-reporter:Xiaochuan Ren, Yanjun Zhai, Lin Zhu, Yanyan He, Aihua Li, Chunli Guo, and Liqiang Xu
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 27) pp:17205-17211
Publication Date(Web):June 20, 2016
DOI:10.1021/acsami.6b03257
Vanadium pentoxide (V2O5) has attracted interesting attention as cathode material for LIBs because of its stable crystal structure and high theoretical specific capacity. However, the low rate performance and poor long-term cycling stability of V2O5 limit its applications. In order to improve its battery performance, various V2O5 hollow microspheres including a yolk–shell structure, double-shell structure, triple-shell structure, and hierarchical hollow superstructures have been selectively prepared. The obtained hierarchical V2O5 hollow microspheres (HVHS) exhibit a high capacity of 123 mAh g–1 at 20 C (1 C = 147 mA g–1) in the range of 2.5–4.0 V, and 73.5 mAh g–1 can be reached after 3000 cycles. HVHS also display good cycling performance in the range of 2.0–4.0 V. Moreover, the V2O5//Li4Ti5O12 full cell was successfully assembled, which exhibits an excellent performance of 139.5 mAh g–1 between 1.0 and 2.5 V at a current density of 147 mA g–1, and a high capacity of 106 mAh g–1 remained after 100 cycles, indicating the good cycling performance and promising application of the full cell.
Co-reporter:Yanjun Zhai, Liqiang Xu, Yitai Qian
Journal of Power Sources 2016 Volume 327() pp:423-431
Publication Date(Web):30 September 2016
DOI:10.1016/j.jpowsour.2016.07.051
•Ce-doped α-FeOOH was synthesized by a hydrothermal method followed acid-treatment.•Ce-doped α-FeOOH for LIBs exhibits 830 mA h g−1 at after 800 cycles.•Ce-doped α-FeOOH for SIBs exhibits an initial capacity of 587 mA h g−1.•Ce-doping reduced the polarization of electrode and promoted cycling performance.Ce-doped α-FeOOH nanorods with high yields were conveniently prepared by a hydrothermal method followed by an acid-treatment process. It is found that Ce uniformly distributes in the α-FeOOH nanorod nanostructures through elemental mapping analysis. The 0.5 wt% Ce-doped α-FeOOH electrode displayed excellent cycling performance with a high discharge capacity of 830 mA h g−1 after 800 charge/discharge cycles at a high current of 2000 mA g−1. The enhanced electrochemical performance can be attributed to the improved electronic conductivity, Li-ion diffusion kinetics and structure stability after Ce doping. Furthermore, a 0.5 wt% Ce-doped α-FeOOH//LiFePO4 lithium ion cell with an initial discharge capacity of 580 mA h g−1 at 1000 mA g−1 based on the total weight of the anode material has been fabricated for the first time. The obtained 0.5 wt% Ce-doped α-FeOOH electrode as anode material for sodium-ion batteries also exhibits a high initial discharge capacity of 587 mA h g−1 at 100 mA g−1.Proper contents of Ce doping in α-FeOOH nanorods have been conveniently fabricated with high yields through a hydrothermal followed an acid-washing method. The 0.5 wt% Ce-doped α-FeOOH suppressed the dramatic drop of specific discharge capacity within the first 100 cycles and exhibits excellent long-term cycling performances (830 mA h g−1 at high current densities of 2000 mA g−1 after 800 cycles). The 0.5 wt% Ce-doped α-FeOOH//LiFePO4 full cell exhibits the initial discharge capacity of ∼580 mA h g−1 at 1000 mA g−1. The excellent performances of the obtained products reveal potential applications as anode for Lithium-ion batteries. When utilized as anode material for Sodium-ion batteries, it exhibits an initial discharge capacity of 587 mA h g−1 at 100 mA g−1. The 0.5 wt% Ce-doped α-FeOOH nanorod could be applied as a highly attractive candidate for energy storage applications that have environmental friendly, low cost and reliability requests.
Co-reporter:Shuling Liu, Hongzhe Zhang, Liqiang Xu, Lanbing Ma, Xiaoxia Chen
Journal of Power Sources 2016 Volume 304() pp:346-353
Publication Date(Web):1 February 2016
DOI:10.1016/j.jpowsour.2015.11.056
•Sn4P3 nanoparticles were synthesized via a simple solvothermal route at 180 °C for 10 h.•The solvent ratio play crucial roles on the size modulation of Sn4P3 nanoparticles.•The long cycle stability of Sn4P3 nanoparticles is firstly reported in this study.•It is the first time to report the rate performance of Sn4P3 nanoparticles.•The Sn4P3 nanoparticles have also been applied as an anode material for Na-ion batteries.Tin phosphide (Sn4P3) nanoparticles with different sizes are synthesized via a facile solvothermal method at 180 °C for 10 h. The as-prepared Sn4P3 nanoparticles have an average size of about 15 nm. Meanwhile, their size could be easily controlled by the solvent ratio. The long cycle stability and rate performance of the as-obtained Sn4P3 nanoparticles have been tested as an anode material for lithium ion batteries for the first time. Electrochemical measurements show that the Sn4P3 nanoparticles with a smallest size give the best cycling and rate performances. They deliver a discharge capacity of 612 mAh g−1 after 10 cycles and could still maintain 442 mAh g−1 after 320 cycles at the current density of 100 mA g−1 within voltage limit of 0.01–3.0 V. Even after 200 cycles at a current density of 200 mA g−1, the specific capacity still could be remained at 315 mAh g−1. The improved electrochemical performances of Sn4P3 electrode might be largely attributed to their small-size. Furthermore, the as-prepared Sn4P3 nanoparticles have also been tested as an anode material for Na-ion batteries, this Sn4P3 anode can deliver a reversible capacity of 305 mAh g−1 after 10 cycles at the current density of 50 mA g−1.The long cycle stability and TEM image of as-obtained Sn4P3 nanoparticles.
Co-reporter:Yanjun Zhai, Hongzhi Mao, Peng Liu, Xiaochuan Ren, Liqiang Xu and Yitai Qian
Journal of Materials Chemistry A 2015 vol. 3(Issue 31) pp:16142-16149
Publication Date(Web):16 Jun 2015
DOI:10.1039/C5TA03017J
The rational design of three-dimensional (3D) hierarchical porous architectures possessing the advantages of improved electrical conductivity and reduced volume change during charge–discharge processes has been proved to be an effective way for enhancing the electrochemical performance of binary metal oxides and related hybrids. Herein, uniform 3D hierarchical porous rose-like NiCo2O4/MnCo2O4 is controllably fabricated through a facile hydrothermal process followed by a subsequent heat treatment, which exhibits high cycling stability (1009 mA h g−1 at 1000 mA g−1 after 600 cycles), high specific capacity and excellent rate capability as anodes for lithium ion batteries. In addition, the NiCo2O4/MnCo2O4 displays an initial specific capacitance of 911.3 F g−1 as a supercapacitor electrode at 5 A g−1. Its excellent electrochemical performances may originate from its unique hierarchical and porous structure, which can buffer the volume expansion and increase the contact area between the electrode and electrolyte. The as-obtained 3D hierarchical porous rose-like NiCo2O4/MnCo2O4 composite exhibits outstanding electrochemical performances, which is a promising candidate for the next-generation energy storage electrodes.
Co-reporter:Guangda Li, Liqiang Xu, Yanjun Zhai and Yaping Hou
Journal of Materials Chemistry A 2015 vol. 3(Issue 27) pp:14298-14306
Publication Date(Web):26 May 2015
DOI:10.1039/C5TA03145A
Uniform hierarchical porous MnCo2O4 and CoMn2O4 microspheres (3–6 μm) were fabricated through a solvothermal process followed by a post-annealing treatment. Fascinatingly, these porous MnCo2O4 and CoMn2O4 microspheres are composed of numerous polyhedral nanoparticles with diameters in the range of 200–500 nm. The porous structure is believed to be beneficial for improving the lithium-storage performance of the products, which can effectively buffer the volume expansion during the Li+ insertion/extraction process and shorten the Li+ diffusion lengths. The polyhedral structure can enhance the electrolyte/electrode contact area and increase the number of Li+ insertion/extraction sites. When used as anode materials for lithium-ion batteries, the porous MnCo2O4 and CoMn2O4 microspheres exhibited excellent long-life cycling performance at high rate density. At a current density of 1000 mA g−1, the MnCo2O4 and CoMn2O4 exhibit an initial capacity of 1034 and 1107 mA h g−1 and the capacity is maintained at 740 and 420 mA h g−1 after 1000 cycles. Furthermore, the growth mechanism of porous microspheres is proposed based on many contrast experiments. The relationship between morphology evolution and annealing time is particularly investigated in detail. It is found that the annealing time plays an important role in obtaining products with different morphologies. Through the controlled annealing time, porous microspheres, yolk–shell microspheres and solid microspheres could be selectively obtained.
Co-reporter:Yanyan He, Liqiang Xu, Yanjun Zhai, Aihua Li and Xiaoxia Chen
Chemical Communications 2015 vol. 51(Issue 79) pp:14768-14771
Publication Date(Web):11 Aug 2015
DOI:10.1039/C5CC03801D
A porous hexangular ring–core NiCo2O4 nanosheet/NiO nanoparticle composite has been synthesized using a hydrothermal method followed by an annealing process in air. The as-obtained composite as an anode material exhibits a high initial discharge capacity of 1920.6 mA h g−1 at a current density of 100 mA g−1 and the capacity is retained at 1567.3 mA h g−1 after 50 cycles. When it is utilized as a catalyst for CO oxidation, complete CO conversion is achieved at 115 °C and a catalytic life test demonstrates the good stability of the composite.
Co-reporter:Yanjun Zhai;Xiaojian Ma;Hongzhi Mao;Weiwei Shao;Yanyan He;Yitai Qian
Advanced Electronic Materials 2015 Volume 1( Issue 6) pp:
Publication Date(Web):
DOI:10.1002/aelm.201400057
Co-reporter:Aihua Li;Shouli Li;Yanyan He;Ranran Zhang;Yanjun Zhai
Nano Research 2015 Volume 8( Issue 2) pp:554-565
Publication Date(Web):2015 February
DOI:10.1007/s12274-014-0669-7
Novel manganese and boron containing nanomaterials have been investigated for applications in rechargeable lithium ion batteries (LIBs) in recent years owing since they are more environmentally-benign and more abundant in nature than the materials currently employed. In this study, one-dimensional (1D) Mn3B7O13OH nanorods and MnBO2OH nanorod bundles were controllably fabricated by using NH4HB4O7 and Mn(NO3)2 as reagents via a hydrothermal or solvothermal process, respectively, without any surfactants or templates at 220 °C. It is interesting to find that both materials are transformed into Mn2OBO3 nanorods/nanorod bundles by subsequent calcination. The formation processes of the above 1D borate containing products were investigated and the as-obtained four kinds of borates were studied as novel anode materials. It was found that the Mn2OBO3 nanorods displayed the best performance among the four borates, delivering an initial discharge capacitiy of 1,172 mAh·g−1 at 100 mA·g−1, and 724 mAh·g−1 could be retained after 120 cycles. A full battery composed of a Mn2OBO3 nanorod anode and a commercial LiFePO4 (or LiCoO2) cathode has also been assembled for the first time, which delivered an initial discharge capacity of 949 mAh·g−1 (779 mAh·g−1 for LiCoO2). The excellent cycle and rate performances of the products reveal their potential applications as anodes for LIBs.
Co-reporter:Ranran Zhang, Yanyan He, Aihua Li and Liqiang Xu
Nanoscale 2014 vol. 6(Issue 23) pp:14221-14226
Publication Date(Web):21 Aug 2014
DOI:10.1039/C4NR03228D
One-dimensional (1D) Mn3O4 nanorod/Zn2SnO4 nanoneedle hierarchical composites were conveniently synthesized via a simple hydrothermal process at 180 °C for 24 h. It was found that the reaction time and an appropriate amount of ammonia play vital roles during their formation process, and their formation is likely driven by the lattice match of the cubic Zn2SnO4 nanoneedles and cubic Mn3O4 nanorods. The as-obtained composites deliver a high initial discharge capacity of 1370.9 mA h g−1 at 100 mA g−1 in the range of 0.01–3.0 V, and a reversible specific capacity of 577.4 mA h g−1 could be retained after 50 cycles. It is noteworthy that 441.5 mA h g−1 could be maintained after 50 cycles even if the current density was set as high as 1000 mA h g−1, and the rate performance of nanocomposites (200, 500, 1000 mA g−1) also shows excellent reversible character. The high specific capacity, good cycling stability and high rate performance of the as-obtained composites enable them to be promising and competitive high-performance anodes in lithium-ion batteries (LIBs). It is worth noting that the fabrication method reported here can be easily extended to prepare other 1D metal oxide hybrid materials including Mn3O4/ZnFe2O4, Mn2O3/CoFe2O4 and Mn2O3/NiFe2O4 composites via a similar hydrothermal process with/without subsequent calcination, which hold great promise for their wide potential applications in energy, catalysis and environmental science and technology.
Co-reporter:Ranran Zhang, Yanyan He and Liqiang Xu
Journal of Materials Chemistry A 2014 vol. 2(Issue 42) pp:17979-17985
Publication Date(Web):28 Aug 2014
DOI:10.1039/C4TA03227F
Hierarchical ZnSn(OH)6 hollow nanospheres that are composed of nanorods have been conveniently prepared via a simple hydrothermal process at 180 °C. It is interesting to find that they could be converted into hierarchical Zn2SnO4 hollow nanospheres after subsequent calcinations. The as-obtained ZnSn(OH)6 and Zn2SnO4 nanospheres deliver initial discharge capacities of 2197.4 and 1618.2 mA h g−1 at 100 mA g−1, and maintain reversible specific capacities of 801.2 (after 60 cycles) and 602.5 mA h g−1 (after 60 cycles), respectively. It is noted that even if the current density was set as high as 1 A g−1, they still could maintain reversible specific capacities of 741.9 (after 1000 cycles) and 442.8 mA h g−1 (after 60 cycles). The facile synthesis, high specific capacity, good cycling stability and high rate performance of the as-obtained hierarchical ZnSn(OH)6 and Zn2SnO4 hollow nanospheres enable them to be promising and competitive high-performance anodes for LIBs.
Co-reporter:Shouli Li, Liqiang Xu, Yanjun Zhai and Hongxiao Yu
RSC Advances 2014 vol. 4(Issue 16) pp:8245-8249
Publication Date(Web):10 Jan 2014
DOI:10.1039/C3RA46482B
The high capacity, negligible toxicity, environmentally benign nature and abundant reserves (low cost of elements contained) of the Fe3BO6 nanomaterial enable it to be a highly promising anode material for lithium-ion batteries. In this study, Fe3BO6 nanorods encapsulated in graphite (defined as “Fe3BO6@C”) core–shell like composites have been produced in situ firstly via a co-pyrolysis approach in a stainless-steel autoclave. After subsequent calcinations, Fe3BO6 nanorods with diameters in the range of 20–50 nm were obtained with high yield, which display a first discharge capacity of 1192 mA h g−1 (with a coulombic efficiency of 70%). It is found that at the current density of 100 mA g−1, the specific capacity of the Fe3BO6 nanorods can remain at 873.2 mA h g−1 after 100 cycles; it is worth noting that their specific capacity can still remain at 710 mA h g−1 even if the current density was set at 1000 mA g−1, indicating the excellent cycle stability and promising applications of the as-obtained Fe3BO6 nanorods utilized as anode material at high power field.
Co-reporter:Shouli Li;Aihua Li;Ranran Zhang;Yanyan He;Yanjun Zhai
Nano Research 2014 Volume 7( Issue 8) pp:1116-1127
Publication Date(Web):2014 August
DOI:10.1007/s12274-014-0474-3
Co-reporter:Shouli Li, Liqiang Xu, Guangda Li, Meng Wang, Yanjun Zhai
Journal of Power Sources 2013 Volume 236() pp:54-60
Publication Date(Web):15 August 2013
DOI:10.1016/j.jpowsour.2013.02.027
Co-reporter:Yuxu Zhang, Liqiang Xu, Bin Tang and Zhiwen Li
Catalysis Science & Technology 2013 vol. 3(Issue 1) pp:222-229
Publication Date(Web):08 Aug 2012
DOI:10.1039/C2CY20122D
Hexagonal boron nitride (h-BN) micromeshes (defined as “BNMM”) of high crystallinity (with diameters of up to 100 μm and pore size of 2.5 μm on average) have been synthesized by using Li2B4O7, Mg and NaN3 in stainless steel autoclaves at 500 °C for 12 h. Through tuning the experimental parameters, BN materials with various morphologies (such as nanospheres or thin films) could also be selectively prepared. The thermal gravimetric analysis (TGA) results of the as-grown BNMM reveal their high thermal stability not only in ambient atmosphere but also in nitrogen atmosphere below 1050 °C. The BNMM were also analyzed by thermomechanical analysis (TMA) in nitrogen atmosphere. The as-obtained BNMM were applied for oxidation of benzyl alcohol and also functionalized by monodispersed Ag particles with potential applications as catalysts for carbon monoxide (CO) oxidation. The results indicate that the BNMM have 37.85% catalytic activity and nearly 100% selectivity in translating benzyl alcohol to benzaldehyde, and the Ag/BNMM composites have catalytic activity for 70.50% of carbon monoxide oxidation.
Co-reporter:Liqiang Xu, Shouli Li, Yuxu Zhang and Yanjun Zhai
Nanoscale 2012 vol. 4(Issue 16) pp:4900-4915
Publication Date(Web):24 Apr 2012
DOI:10.1039/C2NR30598D
Nanoscale nitrides, borides and carbides are a fascinating type of materials, which have aroused tremendous and continuous research interest for decades owing to their special mechanical, electrical, optical, photoelectronic, catalytic properties and widespread uses. In this feature article, recent developments and breakthroughs in the synthesis, properties and applications of nanometre scale nitrides (BN, Si3N4, GaN, noble nitrides), borides (LnB6, LnB2, Fe3BO5, LiMBO3) and carbides (carbon, SiC, TiC, NbC, WC) were briefly reviewed in sequence of their different dimensions (1D, 2D and 3D). In particular, our latest advances in the “autoclave route” fabrication of nanoscale nitrides, borides, and carbides were highlighted. The challenges, issues and perspectives of the synthetic methodologies and potential applications concerning the above-mentioned materials were also briefly discussed.
Co-reporter:Liancheng Wang, Liuliu Shen, Xiaohong Xu, Liqiang Xu and Yitai Qian
RSC Advances 2012 vol. 2(Issue 28) pp:10689-10693
Publication Date(Web):12 Sep 2012
DOI:10.1039/C2RA21325G
In this study, a high yield of uniform h-BN nanocrystals that are composed of two sets of exposed {102} and {002} planes has been prepared by using NaBH4, FeCl3 and NaN3 in a stainless steel autoclave at 750 °C. The cathodoluminescent (CL) properties of the samples indicates their potential application as optoelectronic materials in the ultraviolet region; they have also been used as a gold nanoparticle support for the relatively highly selective oxidation of benzyl alcohol to benzaldehyde (the conversion and selectivity were ∼30% and 98%, respectively).
Co-reporter:Guangda Li, Liqiang Xu, Qin Hao, Meng Wang and Yitai Qian
RSC Advances 2012 vol. 2(Issue 1) pp:284-291
Publication Date(Web):02 Nov 2011
DOI:10.1039/C1RA00631B
Carbon
nanocages (CNCs) with diameters of about 200∼500 nm have been synthesized by a simple method. The electrochemical properties of the CNCs as anode materials were evaluated by discharge/charge measurement and electrochemical impedance spectroscopy. Results showed that the CNCs displayed excellent cycling performance and good rate capability with no noticeable capacity fading up to 50 cycles at current densities of 100, 300 and 500 mA g−1. Their electrochemical properties were significantly improved after annealing treatment of the CNCs at 600 °C. For example, the CNCs(2)-annealed exhibited much better electrochemical performance with a high reversible capacity of 520 mAh g−1 after 50 cycles at current density of 100 mA g−1. A discharge capacity of 380 mAh g−1 can be obtained after 50 cycles at high current density of 500 mA g−1. The results of the Raman, thermal gravimetric and electrochemical impedance analysis indicated that the graphitization degree, electronic conductivity and charge-transfer rate of the CNCs have been improved after annealing treatment.
Co-reporter:Bo Sun;Kaibin Tang;Liancheng Wang;Zhicheng Ju;Yitai Qian
Crystal Research and Technology 2012 Volume 47( Issue 4) pp:467-470
Publication Date(Web):
DOI:10.1002/crat.201100177
Abstract
Sphere-like Mo2C nanoparticles have been synthesized through the reaction of sodium molybdate, anhydrous ethanol and sodium azide at 450 °C for 10 h in a sealed stainless steel autoclave. X-ray powder diffraction results indicated that the final product was Mo2C. Transmission electron microscopy (TEM) and scanning elctron microscopy (SEM) were employed to characterize the as-prepared sample. The sample was mostly composed of sphere-like particles, which has a superconducting transition temperature of 9.5 K, and its calculated surface area is 30.859 m2/g. The experimental parameters such as reaction temperature and reactants were studied to investigate the reaction mechanism. It was found that sodium azide and reaction temperature played key roles in the formation of sphere-like Mo2C nanoparticles. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Co-reporter:Zhongchao Bai;Bo Sun;Dr. Na Fan;Dr. Zhicheng Ju;Menghua Li; Liqiang Xu; Yitai Qian
Chemistry - A European Journal 2012 Volume 18( Issue 17) pp:5319-5324
Publication Date(Web):
DOI:10.1002/chem.201102944
Abstract
Branched MnOOH nanorods with diameters in the range of 50–150 nm and lengths of up to tens of micrometers were prepared by using potassium permanganate (KMnO4) and PEG 400 (PEG=polyethylene glycol) as starting materials through a simple hydrothermal process at 160 °C. After annealing at 300 °C under a N2 atmosphere for 5 h, MnOOH nanorods became gradually dehydrated and transformed into mesoporous Mn3O4 nanorods with a slight size-shrinking. The as-obtained mesoporous Mn3O4 nanorods had an average surface area of 32.88 m2 g−1 and a mean pore size of 3.7 nm. Through tuning the experimental parameters, such as the annealing atmosphere and temperature, β-MnO2, Mn2O3, Mn3O4, MnO, and Mn5O8 were selectively produced. Among these structures, mesoporous Mn3O4 nanorods were efficient for the catalytic degradation of methylene blue (MB) in the presence of H2O2 at 80 °C.
Co-reporter:Guangda Li, Hongxiao Yu, Liqiang Xu, Qiang Ma, Chao Chen, Qin Hao and Yitai Qian
Nanoscale 2011 vol. 3(Issue 8) pp:3251-3257
Publication Date(Web):15 Jul 2011
DOI:10.1039/C1NR10284B
Carbon
nanocages (CNCs) have been synthesized through a simple approach using different alcohols and ferrous oxalate as reactants at 550 °C for 12 h in a sealed autoclave. The lengths of the sides of the CNCs are about 200–350 nm and the wall thicknesses are about 10–15 nm. The formation mechanism of the CNCs is also discussed, based on the experimental results. These CNCs show excellent removal efficiency for phenolic compounds, ammonia, and total particulate matter from cigarette smoke. The adsorption capability of CNCs prepared from ethanol is much higher than that of other samples. For example, the efficiency of 5 mg CNCs (ethanol) for removing the six phenolic compounds p-dihydroxybenzene, m-dihydroxybenzene, o-dihydroxybenzene, phenol, m-cresol, and o-cresol can reach 57.31%, 62.25%, 65.58%, 75.95%, 54.34% and 59.43%, respectively, while that of the commercial activated carbon (5 mg) can only reach 29.02%, 33.93%, 35.00%, 36.00%, 20.33% and 36.19%, respectively, under the same conditions.
Co-reporter:Meng Wang, Menghua Li, Liqiang Xu, Liancheng Wang, Zhicheng Ju, Guangda Li and Yiti Qian
Catalysis Science & Technology 2011 vol. 1(Issue 7) pp:1159-1165
Publication Date(Web):11 Jul 2011
DOI:10.1039/C1CY00111F
In this study, hexagonal boron nitride submicro-boxes (BNMB) (0.50–1.4 μm) have been synthesized by using KBH4, NH4F and Zn in a stainless steel autoclave at 450 °C. The formation process was studied by XRD, TEM and EDS, and it is considered that the in situ formed KZnF3 intermediate cubes serve as templates for the formation of BNMB. The as-formed BNMB, with unique structural features, high specific surface area (∼86.9 m2 g−1) and good chemical properties, can be applied as a catalyst support for SnO2. The UV-Vis diffuse reflectance spectrum of SnO2/BNMB shows the absorption edge in the visible region (∼470 nm), making it suitable for photocatalytic application. The experimental result indicates that the SnO2/BNMB exhibited excellent photocatalytic activity on the degradation of methyl orange (MO), which was up to 92% after 30 min of visible-light (λ > 420 nm) irradiation. The good photocatalytic activity was attributed mainly to its suitable band gap energy, strong adsorption ability for MO, and effective charge separation at the SnO2/BNMB photocatalyst interface.
Co-reporter:Liancheng Wang, Changhui Sun, Liqiang Xu and Yitai Qian
Catalysis Science & Technology 2011 vol. 1(Issue 7) pp:1119-1123
Publication Date(Web):25 Jul 2011
DOI:10.1039/C1CY00191D
In this study, gram scale ultrathin (4 nm on average) boron nitride nanosheets (BNNSs) have been prepared through a simple route by using boron oxide, zinc powders and N2H4·2HCl in a stainless steel autoclave at 500 °C. The high thermal stability and high specific surface area (226 m2 g−1) of these BNNSs enable them to be candidates for the high efficiency catalyst support. For example, monodispersed Pt and Au nanoparticles with mean diameters of ∼4.0 and 3.3 nm were successfully loaded on the surfaces of BNNSs, respectively. The Au/BNNSs and Pt/BNNSs would be efficient catalysts in various reactions. It is found that the Pt/BNNSs catalysts towards CO conversion have shown lower full conversion temperature and higher stability. Besides, the gram scale BNNSs might have many other potential applications, such as in polymer composites with high thermal conductivity, electron field emission and the absorbent in gas/water purification.
Co-reporter:Qin Hao, Houyi Ma, Zhicheng Ju, Guangda Li, Xiaowei Li, Liqiang Xu, Yitai Qian
Electrochimica Acta 2011 Volume 56(Issue 25) pp:9027-9031
Publication Date(Web):30 October 2011
DOI:10.1016/j.electacta.2011.04.097
LiCoO2 nanoparticles were prepared through a sol–gel method, and then appropriate amount of CuO nanoparticles were deposited onto their surfaces to improve their cycling performances. It is found that the CuO coated sample has the capacity retention higher than 90% at the rates below 30 C after 10 cycles, which also has the highest capacities of 135 and 123 mAh g−1 at 40 C (5480 mA g−1) and 50 C (6850 mA g−1), respectively. The cyclic voltammograms result reveals that the CuO coating reduces the polarization and improves the electrochemical activity of cathode. In addition, experimental results indicate that CuO coating plays an important role in reducing the charge transfer resistance of the cell during cycling, which has been demonstrated by the electrochemistry impedance spectroscopy analysis. The above data indicate the potential application of CuO coated LiCoO2 in high power field.Graphical abstractLiCoO2 particles were synthesized through a sol–gel route. Then, they were surface modified by CuO for the first time. The result indicates that the CuO coated samples shows much better cycling stability than the pristine one, which has the capacity retention higher than 90% at the rates below 30 C after 10 cycles, and retains the highest capacities of 135 and 123 mAh g−1 at 40 C and 50 C, respectively. These data indicate the potential application of CuO coated LiCoO2 in high power field.Highlights► CuO nanoparticles were successfully used to improve the cycling performance of LiCoO2 for the first time. ► The high-rate performance of CuO coated LiCoO2 was investigated, and it performed better than the reported coated LiCoO2 materials, even at the current density higher than 5000 mAh g−1. ► The role of CuO coating was discussed detailedly.
Co-reporter:Qin Hao, Liqiang Xu, Guangda Li, Zhicheng Ju, Changhui sun, Houyi Ma, Yitai Qian
Journal of Alloys and Compounds 2011 Volume 509(Issue 21) pp:6217-6221
Publication Date(Web):26 May 2011
DOI:10.1016/j.jallcom.2011.03.005
MnO nanospheres encapsulated in carbon (MnO/C) composites were synthesized through a one-step solid state reaction between potassium permanganate and salicylic acid at 700 °C, which could be transformed into MnO2 nanorods after being annealed in ambient atmosphere. Their formation mechanisms and electrochemical performances as anodes in Li-ion batteries (LIBs) were investigated. The first discharge capacity of MnO/C composites was 585.9 mA h g−1, while that of MnO2 was 1269 mA h g−1, indicating their potential applications in LIBs.Graphical abstractHighlights► The MnO/C core-shell like composites were synthesized, and they could be transformed into uniform MnO2 nanorods after the annealling process. ► The formation mechanisms of MnO/C composites and MnO2 nanorods are discussed in the article. ► The electrochemical performances and possible applications of the products as anodes in Li-ion batteries have been investigated.
Co-reporter:Zhongchao Bai, Zhicheng Ju, Liancheng Wang, Bo Sun, Changhui Sun, Liqiang Xu, Yitai Qian
Materials Letters 2011 Volume 65(15–16) pp:2479-2481
Publication Date(Web):August 2011
DOI:10.1016/j.matlet.2011.05.039
Urchin-like Fe3BO5@carbon core–shell structures (defined as “FBOC”) have been fabricated by a one-step co-pyrolysis method using boric acid and ferrocene as raw materials. This complex architecture is composed of high-density Fe3BO5@carbon nanocables that stand on Fe3BO5@carbon structure. After removing the Fe3BO5, hollow urchin-like carbon material was obtained. In the reaction process, B2O3 and H2O that decomposed from H3BO3 have synergistic effect on the formation of urchin-like structures. It is found that urchin-like structures can also be obtained when other materials that can release H2O and B2O3 react with ferrocene. The influences of the reaction conditions on the preparation of FBOC have been discussed in detail.
Co-reporter:Zhicheng Ju, Tingting Wang, Liancheng Wang, Zheng Xing, Liqiang Xu, Yitai Qian
Carbon 2010 Volume 48(Issue 12) pp:3420-3426
Publication Date(Web):October 2010
DOI:10.1016/j.carbon.2010.05.037
Leaf-like carbon sheets have been obtained by the pyrolysis of dichloromethane and ferrocene in an autoclave in 300–600 °C on Cu ribbons for 90 min. The thickness of the sheets could be controlled from 50 to 200 nm by adjusting the experimental parameters. The formation process was studied by observing product-evolution utilizing the real-time imaging capabilities of emission scanning electron microscope, and it is considered that Diffusion-Limited Aggregation mechanism could be responsible for their growth. Thermo-gravimetric analysis curves show that the initial thermal decomposition temperature of the carbon sheets increases from 300 to 420 °C with the increasing preparation temperature. The Brunauer–Emmett–Teller specific surface area was 398 m2/g and with a narrow pore distribution in the range of 2–5 nm. By changing the carbon sources, solid carbon spheres as well as chain-like solid carbon spheres (3–5 μm) could be selectively prepared using one-pot reactions.
Co-reporter:Lishan Yang, Hongxiao Yu, Liqiang Xu, Qiang Ma and Yitai Qian
Dalton Transactions 2010 vol. 39(Issue 11) pp:2855-2860
Publication Date(Web):05 Feb 2010
DOI:10.1039/B920429F
A series of nitrides (TiN, ZrN, BN, AlN) were prepared by using the corresponding elements (Ti, Zr, B, Al), NaN3 and sulfur as starting materials in a stainless steel autoclave at 250 °C. Sulfur was used to facilitate the exothermic reaction between NaN3 and sulfur (at 250 °C) and the final formation of nitrides. The treatment temperature affected the growth of the nitride crystals, for example, diversified morphologies of TiN nanocrystals were formed in different temperature ranges: grain and truncated octahedron (250 °C), octahedron (>300 °C), and dendrite (>400 °C). Through similar processes, other nitrides (for example, TiN, AlN, Si3N4) could also be produced by employing NaNH2 and additives (such as iodine or N-aminothiourea instead of sulfur) in low temperatures.
Co-reporter:Liancheng Wang, Liqiang Xu, Zhicheng Ju and Yitai Qian
CrystEngComm 2010 vol. 12(Issue 11) pp:3923-3928
Publication Date(Web):27 Jul 2010
DOI:10.1039/C001167C
In this study, a versatile route is reported for the convenient synthesis of rare-earth hexaborides (RB6, R = La, Ce, Pr, Nd, Sm, Eu) and alkaline-earth hexaborides (AB6, A = Ca, Sr, Ba). The single crystalline cube-like RB6 (R = La, Ce, Pr, Sm, Eu) with mean sizes ranging from 450 to 700 nm were prepared through the co-reduction of rare-earth oxides and boric acid by Mg powder with the assistance of I2 at 170–250 °C. Similarly, NdB6 as well as AB6 (A = Ca, Sr, Ba) can be produced at 350 °C. It is found that CaB6 nanorods with a proportion above 20% and lengths up to several micrometres were produced using CaO as calcium source. When CaCO3 was used instead of CaO, single crystalline hollow CaB6 cages were obtained at 400 °C. The cube-like LaB6 was taken as an example for the synthesis of a series of hexaborides by adjusting the experimental parameters.
Co-reporter:Qiaolian Pang, Liqiang Xu, Zhicheng Ju, Zheng Xing, Lishan Yang, Qin Hao, Yitai Qian
Journal of Alloys and Compounds 2010 Volume 501(Issue 1) pp:60-66
Publication Date(Web):2 July 2010
DOI:10.1016/j.jallcom.2010.04.028
Cubic phase silicon carbide (3C-SiC) nanowires (labeled as “Sample 1”) with diameters ranging from 10 nm to 80 nm and lengths up to several micrometers were obtained by using CHI3, Si powder, and metallic Na as reactants at 230 °C. In addition, SiC polyhedra (labeled as “Sample 2”) with smooth surfaces and diameters of 2–5 μm were obtained by using the different amounts of the same reactants at 500 °C. The room-temperature photoluminescence (PL) spectra of Sample 1 and Sample 2 show strong ultraviolet emission peaks centered at 360 nm and 354 nm, respectively. Thermal gravimetric analysis (TGA) curves reveal that the thermal stability (against air oxidation) of Sample 2 is better than Sample 1. The possible formation mechanisms of the products with distinct dimensions were briefly discussed.
Co-reporter:Zheng Xing, Qin Hao, Zhicheng Ju, Liqiang Xu, Yitai Qian
Materials Letters 2010 Volume 64(Issue 12) pp:1401-1403
Publication Date(Web):30 June 2010
DOI:10.1016/j.matlet.2010.03.042
Rhombohedra microcrystallites of magnesium carbonate (MgCO3) have been hydrothermally synthesized by urea and magnesium sources (Mg, MgCl2, Mg(OH)2, MgSO4, and MgO) at 160 °C. The experimental parameters such as reaction temperature, time, and reactants were researched to investigate the reaction mechanism. The product synthesized by Mg powder was about 10 μm, and the diameters of the products synthesized by Mg(OH)2 and MgSO4 were about 1–2 μm. The product could transfer from the mixture of MgCO3, Mg(OH)2, Mg5(CO3)4(OH)2·4H2O to pure MgCO3 by increasing reaction time or raising reaction temperature, which indicates that Mg5(CO3)4(OH)2·4H2O was just the intermediate product, and MgCO3 was the final product.
Co-reporter:Menghua Li, Liqiang Xu, Changhui Sun, Zhicheng Ju and Yitai Qian
Journal of Materials Chemistry A 2009 vol. 19(Issue 43) pp:8086-8091
Publication Date(Web):24 Sep 2009
DOI:10.1039/B912451A
The shape evolution from uniform triangular boron nitride nanoplates of rhombohedral phase (r-BN) to hexagonal r-BN nanoplates was achieved through a simple calcination process in flowing N2 at 1000 °C for 8 h. The average thickness of the triangular and hexagonal r-BN nanoplates is similar (∼50 nm), while their average edge sizes are 360 and 320 nm, and their intense emission bands are centered at 316 and 297 nm (λex = 200 nm), respectively. TGA analysis results reveal that hexagonal r-BN nanoplates have superior thermal stability compared with the triangular nanoplates especially above 800 °C under ambient atmosphere. The possible mechanism of the thermally induced conversion from triangular to hexagonal r-BN nanoplates is discussed.
Co-reporter:Liancheng Wang, Liqiang Xu, Changhui Sun and Yitai Qian
Journal of Materials Chemistry A 2009 vol. 19(Issue 14) pp:1989-1994
Publication Date(Web):11 Feb 2009
DOI:10.1039/B817481D
In this study, hexagonal boron nitride (h-BN) micromeshes with high crystallinity and yield have been prepared by B2O3, Mg and NaN3 in a stainless steel autoclave at 450 °C, which have diameters of up to 100 µm, thickness of ∼210 nm and pore size of 2.8 µm on average. A near-band edge emission at 217 nm of these micromeshes has been observed through the photoluminescence (PL) spectra. Their formation mechanism was considered through an oriented aggregation process, in which the in-situ produced MgO microparticles served as template. As B2O3 was substituted by other boron sources (such as H3BO3, Na2B4O7, NH4HB4O7 or Mg(BO2)2·H2O), h-BN micromeshes with different pore sizes could also be produced; therefore, it is a general way for the convenient synthesis of crystalline h-BN micromeshes. The as-obtained product is promising as a catalyst support, in chemical filtration and in separations under severe operating conditions.
Co-reporter:Na Fan, Hongxiao Yu, Zhicheng Ju, Qiang Ma, Yanqi Hu, Liqiang Xu, Yitai Qian
Materials Letters 2009 Volume 63(Issue 5) pp:551-553
Publication Date(Web):28 February 2009
DOI:10.1016/j.matlet.2008.11.017
Hierarchical cobalt dendrites with ferromagnetic properties have been synthesized by using the in situ produced cobalt carbonate together with cobalt oxalate as precursor and hypophosphite (H2PO2−) as the reducing agent in mixed solutions at 160 °C. XRD and SAED patterns reveal that the as-prepared cobalt dendrites have a single-crystalline structure with a [001] growth orientation. The shape evolution of the hierarchical cobalt dendrites was investigated.
Co-reporter:Shuling Liu, Yitai Qian, Liqiang Xu
Solid State Communications 2009 Volume 149(11–12) pp:438-440
Publication Date(Web):March 2009
DOI:10.1016/j.ssc.2008.12.046
In this paper, hollow spherical Cu3P nanopowders were synthesized by using copper sulfate pentahydrate (CuSO4⋅5H2O) and yellow phosphorus in a mixed solvent of glycol, ethanol and water at 140–180 ∘C for 12 h. X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), electron diffraction pattern (ED) and transmission electronic microscopy (TEM) studies show that the as-synthesized nanocrystal is pure hexagonal phase Cu3P with a hollow spherical morphology. Based on the TEM observations, a possible aggregation growth mechanism was proposed for the formation of Cu3P hollow structures. Meanwhile, the effects of some key factors such as solvents, reaction temperature and reaction time on the final formation of the Cu3P hollow structure were also discussed.
Co-reporter:Qin Hao, Liqiang Xu, Guangda Li and Yitai Qian
Langmuir 2009 Volume 25(Issue 11) pp:6363-6367
Publication Date(Web):May 8, 2009
DOI:10.1021/la8041499
Copper microparticles (2−5 um) encapsulated in carbonaceous shell polyhedral composites were mildly prepared via a one-pot hydrothermal process using copper nitrate, glucose, and sodium citrate at 150 °C, in which the glucose was found to play reducer and graphite source roles during the formation of these core−shell-like composites. Thermal stability results indicated that their weights remain almost unchanged below 240 °C in ambient atmosphere. It is interesting that the copper microparticles could be partially released out and translated into monodisperse Cu nanoparticles around the initial composites under the convergent electron beams in a transmission electron microscope (TEM). This phenomenon is an appealing discovery, which might endow the Cu@C composite with new functions; for example, it might be applied as a sensitive detector for the leakage of electron beams or other substances for the sake of being a safeguard. In addition, the corresponding hollow carbonaceous polyhedra were also obtained after the acid treatment, which might be used as a template to fabricate other kinds of polyhedra.
Co-reporter:Peng Li, Liqiang Xu and Yitai Qian
Crystal Growth & Design 2008 Volume 8(Issue 7) pp:2431-2436
Publication Date(Web):June 14, 2008
DOI:10.1021/cg800008f
3C-SiC hollow nanospheres with a high yield (∼80%) were prepared by using SiCl4, CBr3H, and Na-K alloy at 130 °C for 15 h and a subsequent HClO4 treatment process at 180 °C. These SiC hollow nanospheres have diameters in the range of 80−120 nm and an average shell thickness of ∼15 nm. High resolution transmission electron microscopy investigation reveals that these hollow spherical nanocrystals have rough surfaces, indicating they are composed of nanoparticles. When Na−K alloy was substituted by Na (or K) and in the mean time the temperature was set at 240 °C while keeping other conditions unchanged, a large quantity of randomly distributed and highly crystalline SiC nanowires with diameters ranging from 30 to 50 nm and lengths up to several tens of micrometers also can be produced. The possible formation mechanisms of the products with distinct dimensions were briefly discussed. The method used here generally could be used to synthesize other carbides at low temperature.
Co-reporter:Zhicheng Ju;Zheng Xing;Chunli Guo;Lishan Yang, ;Yitai Qian
European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 24) pp:3883-3888
Publication Date(Web):
DOI:10.1002/ejic.200800198
Abstract
Silicon carbide (SiC) nanowires coexisting with amorphous graphite particles were initially produced by using silicon powder, tetrachlorethylene, metallic Na, and sulfur powder as reactants in an autoclave at 130 °C. Pure β-SiC could be finally obtained after heating the sample in concentrated H2SO4 by refluxing at 180 °C, which was proved by the X-ray powder diffraction patterns. Transmission electron microscopy (TEM) images and scanning electron microscope (SEM) images show that the product is mainly composed of SiC nanowires (over 75 %) with an average diameter of about of 30 nm and lengths up to tens of micrometers. High-resolution TEM shows that the nanowires have preferential growth along the [111] direction. It was found that when sulfur was absent, crystalline β-SiC powders could not be obtained unless the target temperature was raised higher than 270 °C. In the mean time, the ratio of the nanowires also dropped dramatically (≈20 %). The effects of sulfur, reaction time, and temperature on the morphologies of the final products, together with the properties of the final products, were also discussed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Co-reporter:Aihua Li, Zhenyu Feng, Yan Sun, Limei Shang, Liqiang Xu
Journal of Power Sources (1 March 2017) Volume 343() pp:424-430
Publication Date(Web):1 March 2017
DOI:10.1016/j.jpowsour.2017.01.079
Co-reporter:Changhui Sun, Chunli Guo, Xiaojian Ma, Liqiang Xu, Yitai Qian
Journal of Crystal Growth (1 July 2009) Volume 311(Issue 14) pp:3682-3686
Publication Date(Web):1 July 2009
DOI:10.1016/j.jcrysgro.2009.05.019
Hexagonal boron nitride (h-BN) particles including hollow spheres (with a proportion of ~30–40%) and nanotubes (10%) have been synthesized by using sodium fluoroborate and sodium azide at 450 °C for 20 h. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) studies show that the as-obtained BN hollow particles are crystalline. The total specific surface area of the product calculated from Brunauer–Emmentt–Teller (BET) absorption measurement is 89.79 m2/g, indicating that it may be utilized as a promising candidate for hydrogen storage container or catalyst. Thermal gravimetric analysis (TGA) result reveals its excellent thermal stability below 800 °C. Its possible growth mechanism and the effects of reaction parameters were also briefly discussed.
Co-reporter:Menghua Li, Liqiang Xu, Changhui Sun, Zhicheng Ju and Yitai Qian
Journal of Materials Chemistry A 2009 - vol. 19(Issue 43) pp:NaN8091-8091
Publication Date(Web):2009/09/24
DOI:10.1039/B912451A
The shape evolution from uniform triangular boron nitride nanoplates of rhombohedral phase (r-BN) to hexagonal r-BN nanoplates was achieved through a simple calcination process in flowing N2 at 1000 °C for 8 h. The average thickness of the triangular and hexagonal r-BN nanoplates is similar (∼50 nm), while their average edge sizes are 360 and 320 nm, and their intense emission bands are centered at 316 and 297 nm (λex = 200 nm), respectively. TGA analysis results reveal that hexagonal r-BN nanoplates have superior thermal stability compared with the triangular nanoplates especially above 800 °C under ambient atmosphere. The possible mechanism of the thermally induced conversion from triangular to hexagonal r-BN nanoplates is discussed.
Co-reporter:Liancheng Wang, Liqiang Xu, Changhui Sun and Yitai Qian
Journal of Materials Chemistry A 2009 - vol. 19(Issue 14) pp:NaN1994-1994
Publication Date(Web):2009/02/11
DOI:10.1039/B817481D
In this study, hexagonal boron nitride (h-BN) micromeshes with high crystallinity and yield have been prepared by B2O3, Mg and NaN3 in a stainless steel autoclave at 450 °C, which have diameters of up to 100 µm, thickness of ∼210 nm and pore size of 2.8 µm on average. A near-band edge emission at 217 nm of these micromeshes has been observed through the photoluminescence (PL) spectra. Their formation mechanism was considered through an oriented aggregation process, in which the in-situ produced MgO microparticles served as template. As B2O3 was substituted by other boron sources (such as H3BO3, Na2B4O7, NH4HB4O7 or Mg(BO2)2·H2O), h-BN micromeshes with different pore sizes could also be produced; therefore, it is a general way for the convenient synthesis of crystalline h-BN micromeshes. The as-obtained product is promising as a catalyst support, in chemical filtration and in separations under severe operating conditions.
Co-reporter:Ranran Zhang, Yanyan He and Liqiang Xu
Journal of Materials Chemistry A 2014 - vol. 2(Issue 42) pp:NaN17985-17985
Publication Date(Web):2014/08/28
DOI:10.1039/C4TA03227F
Hierarchical ZnSn(OH)6 hollow nanospheres that are composed of nanorods have been conveniently prepared via a simple hydrothermal process at 180 °C. It is interesting to find that they could be converted into hierarchical Zn2SnO4 hollow nanospheres after subsequent calcinations. The as-obtained ZnSn(OH)6 and Zn2SnO4 nanospheres deliver initial discharge capacities of 2197.4 and 1618.2 mA h g−1 at 100 mA g−1, and maintain reversible specific capacities of 801.2 (after 60 cycles) and 602.5 mA h g−1 (after 60 cycles), respectively. It is noted that even if the current density was set as high as 1 A g−1, they still could maintain reversible specific capacities of 741.9 (after 1000 cycles) and 442.8 mA h g−1 (after 60 cycles). The facile synthesis, high specific capacity, good cycling stability and high rate performance of the as-obtained hierarchical ZnSn(OH)6 and Zn2SnO4 hollow nanospheres enable them to be promising and competitive high-performance anodes for LIBs.
Co-reporter:Yanjun Zhai, Hongzhi Mao, Peng Liu, Xiaochuan Ren, Liqiang Xu and Yitai Qian
Journal of Materials Chemistry A 2015 - vol. 3(Issue 31) pp:NaN16149-16149
Publication Date(Web):2015/06/16
DOI:10.1039/C5TA03017J
The rational design of three-dimensional (3D) hierarchical porous architectures possessing the advantages of improved electrical conductivity and reduced volume change during charge–discharge processes has been proved to be an effective way for enhancing the electrochemical performance of binary metal oxides and related hybrids. Herein, uniform 3D hierarchical porous rose-like NiCo2O4/MnCo2O4 is controllably fabricated through a facile hydrothermal process followed by a subsequent heat treatment, which exhibits high cycling stability (1009 mA h g−1 at 1000 mA g−1 after 600 cycles), high specific capacity and excellent rate capability as anodes for lithium ion batteries. In addition, the NiCo2O4/MnCo2O4 displays an initial specific capacitance of 911.3 F g−1 as a supercapacitor electrode at 5 A g−1. Its excellent electrochemical performances may originate from its unique hierarchical and porous structure, which can buffer the volume expansion and increase the contact area between the electrode and electrolyte. The as-obtained 3D hierarchical porous rose-like NiCo2O4/MnCo2O4 composite exhibits outstanding electrochemical performances, which is a promising candidate for the next-generation energy storage electrodes.
Co-reporter:Aihua Li, Liqiang Xu, Chang Ming Li and Yitai Qian
Journal of Materials Chemistry A 2016 - vol. 4(Issue 15) pp:NaN5494-5494
Publication Date(Web):2016/03/10
DOI:10.1039/C6TA01624C
Mesh-like LiZnBO3/C composite was synthesized via a facile polymer pyrolysis method for use as an anode in lithium ion batteries (LIBs), demonstrating high initial capacity (860 mA h g−1) and excellent cycle stability (559 mA h g−1 after 600 cycles at 500 mA g−1 with a capacity retention of 94.47%). Ex situ XRD tests indicate a mixed intercalation–conversion–alloy lithium storage mechanism in the first discharge/charge process of the composite. In addition, the LiZnBO3/C anode was coupled with a commercial LiCoO2 cathode in a full cell, which presented an initial reversible capacity of 658 mA h g−1 at 100 mA g−1 and a capacity of 603 mA h g−1 after 400 cycles with average 0.02% fading in each cycle, which greatly outperforms previously reported compounds; this could be attributed to the unique mesh-like morphology of the composite, which enables high mass transport rate and good conductivity, and the coexistence of LiZnBO3–ZnO–Zn composites that produce a synergistic effect for fast kinetics. This study holds great promise for LIBs with high capacity and good stability.
Co-reporter:Lishan Yang, Hongxiao Yu, Liqiang Xu, Qiang Ma and Yitai Qian
Dalton Transactions 2010 - vol. 39(Issue 11) pp:NaN2860-2860
Publication Date(Web):2010/02/05
DOI:10.1039/B920429F
A series of nitrides (TiN, ZrN, BN, AlN) were prepared by using the corresponding elements (Ti, Zr, B, Al), NaN3 and sulfur as starting materials in a stainless steel autoclave at 250 °C. Sulfur was used to facilitate the exothermic reaction between NaN3 and sulfur (at 250 °C) and the final formation of nitrides. The treatment temperature affected the growth of the nitride crystals, for example, diversified morphologies of TiN nanocrystals were formed in different temperature ranges: grain and truncated octahedron (250 °C), octahedron (>300 °C), and dendrite (>400 °C). Through similar processes, other nitrides (for example, TiN, AlN, Si3N4) could also be produced by employing NaNH2 and additives (such as iodine or N-aminothiourea instead of sulfur) in low temperatures.
Co-reporter:Yanyan He, Liqiang Xu, Yanjun Zhai, Aihua Li and Xiaoxia Chen
Chemical Communications 2015 - vol. 51(Issue 79) pp:NaN14771-14771
Publication Date(Web):2015/08/11
DOI:10.1039/C5CC03801D
A porous hexangular ring–core NiCo2O4 nanosheet/NiO nanoparticle composite has been synthesized using a hydrothermal method followed by an annealing process in air. The as-obtained composite as an anode material exhibits a high initial discharge capacity of 1920.6 mA h g−1 at a current density of 100 mA g−1 and the capacity is retained at 1567.3 mA h g−1 after 50 cycles. When it is utilized as a catalyst for CO oxidation, complete CO conversion is achieved at 115 °C and a catalytic life test demonstrates the good stability of the composite.
Co-reporter:Guangda Li, Liqiang Xu, Yanjun Zhai and Yaping Hou
Journal of Materials Chemistry A 2015 - vol. 3(Issue 27) pp:NaN14306-14306
Publication Date(Web):2015/05/26
DOI:10.1039/C5TA03145A
Uniform hierarchical porous MnCo2O4 and CoMn2O4 microspheres (3–6 μm) were fabricated through a solvothermal process followed by a post-annealing treatment. Fascinatingly, these porous MnCo2O4 and CoMn2O4 microspheres are composed of numerous polyhedral nanoparticles with diameters in the range of 200–500 nm. The porous structure is believed to be beneficial for improving the lithium-storage performance of the products, which can effectively buffer the volume expansion during the Li+ insertion/extraction process and shorten the Li+ diffusion lengths. The polyhedral structure can enhance the electrolyte/electrode contact area and increase the number of Li+ insertion/extraction sites. When used as anode materials for lithium-ion batteries, the porous MnCo2O4 and CoMn2O4 microspheres exhibited excellent long-life cycling performance at high rate density. At a current density of 1000 mA g−1, the MnCo2O4 and CoMn2O4 exhibit an initial capacity of 1034 and 1107 mA h g−1 and the capacity is maintained at 740 and 420 mA h g−1 after 1000 cycles. Furthermore, the growth mechanism of porous microspheres is proposed based on many contrast experiments. The relationship between morphology evolution and annealing time is particularly investigated in detail. It is found that the annealing time plays an important role in obtaining products with different morphologies. Through the controlled annealing time, porous microspheres, yolk–shell microspheres and solid microspheres could be selectively obtained.
Co-reporter:Yuxu Zhang, Liqiang Xu, Bin Tang and Zhiwen Li
Catalysis Science & Technology (2011-Present) 2013 - vol. 3(Issue 1) pp:NaN229-229
Publication Date(Web):2012/08/08
DOI:10.1039/C2CY20122D
Hexagonal boron nitride (h-BN) micromeshes (defined as “BNMM”) of high crystallinity (with diameters of up to 100 μm and pore size of 2.5 μm on average) have been synthesized by using Li2B4O7, Mg and NaN3 in stainless steel autoclaves at 500 °C for 12 h. Through tuning the experimental parameters, BN materials with various morphologies (such as nanospheres or thin films) could also be selectively prepared. The thermal gravimetric analysis (TGA) results of the as-grown BNMM reveal their high thermal stability not only in ambient atmosphere but also in nitrogen atmosphere below 1050 °C. The BNMM were also analyzed by thermomechanical analysis (TMA) in nitrogen atmosphere. The as-obtained BNMM were applied for oxidation of benzyl alcohol and also functionalized by monodispersed Ag particles with potential applications as catalysts for carbon monoxide (CO) oxidation. The results indicate that the BNMM have 37.85% catalytic activity and nearly 100% selectivity in translating benzyl alcohol to benzaldehyde, and the Ag/BNMM composites have catalytic activity for 70.50% of carbon monoxide oxidation.
Co-reporter:Meng Wang, Menghua Li, Liqiang Xu, Liancheng Wang, Zhicheng Ju, Guangda Li and Yiti Qian
Catalysis Science & Technology (2011-Present) 2011 - vol. 1(Issue 7) pp:NaN1165-1165
Publication Date(Web):2011/07/11
DOI:10.1039/C1CY00111F
In this study, hexagonal boron nitride submicro-boxes (BNMB) (0.50–1.4 μm) have been synthesized by using KBH4, NH4F and Zn in a stainless steel autoclave at 450 °C. The formation process was studied by XRD, TEM and EDS, and it is considered that the in situ formed KZnF3 intermediate cubes serve as templates for the formation of BNMB. The as-formed BNMB, with unique structural features, high specific surface area (∼86.9 m2 g−1) and good chemical properties, can be applied as a catalyst support for SnO2. The UV-Vis diffuse reflectance spectrum of SnO2/BNMB shows the absorption edge in the visible region (∼470 nm), making it suitable for photocatalytic application. The experimental result indicates that the SnO2/BNMB exhibited excellent photocatalytic activity on the degradation of methyl orange (MO), which was up to 92% after 30 min of visible-light (λ > 420 nm) irradiation. The good photocatalytic activity was attributed mainly to its suitable band gap energy, strong adsorption ability for MO, and effective charge separation at the SnO2/BNMB photocatalyst interface.
Co-reporter:Liancheng Wang, Changhui Sun, Liqiang Xu and Yitai Qian
Catalysis Science & Technology (2011-Present) 2011 - vol. 1(Issue 7) pp:NaN1123-1123
Publication Date(Web):2011/07/25
DOI:10.1039/C1CY00191D
In this study, gram scale ultrathin (4 nm on average) boron nitride nanosheets (BNNSs) have been prepared through a simple route by using boron oxide, zinc powders and N2H4·2HCl in a stainless steel autoclave at 500 °C. The high thermal stability and high specific surface area (226 m2 g−1) of these BNNSs enable them to be candidates for the high efficiency catalyst support. For example, monodispersed Pt and Au nanoparticles with mean diameters of ∼4.0 and 3.3 nm were successfully loaded on the surfaces of BNNSs, respectively. The Au/BNNSs and Pt/BNNSs would be efficient catalysts in various reactions. It is found that the Pt/BNNSs catalysts towards CO conversion have shown lower full conversion temperature and higher stability. Besides, the gram scale BNNSs might have many other potential applications, such as in polymer composites with high thermal conductivity, electron field emission and the absorbent in gas/water purification.
