POLYMER
·
2017
·
IF 3.684
Yanzhi Zhao,Juying Zhou,Fuhou Lei,Haitang Xu,Jianfang Lu,Zaiying Huang,Qin Huang,Pengfei Li
In this work, amphiphilic acrylicpimaric acid polyglycol ester (APAPG) was synthesized by steglich esterification method. The structure transformation and aggregation behaviors of APAPG in water were investigated by Rayleigh light scattering (RLS) technique in a heating and cooling cycle. For concentration above critical micelle concentration (CMC), a reversible transition from micelle to aggregation was observed. The structure transformation process involved irreversible aggregation and disaggregation processes at low temperature and a reversible aggregation process at high temperature when the concentration closed to CMC. Accordingly, the information about each structure transformation behavior in the concentration far below CMC during heating process including individual unimers, aggregation and disaggregation were thoroughly revealed. However, the structure transformation behavior is irreversible in the cooling process. The structure transformation and aggregation behaviors were assessed by dynamic light scattering (DLS), microcalorimetry and scanning electron microscopy (SEM) techniques. The results indicate that the RLS technique can provide detailed information about structural evolution at molecular level of polymer chains.
研究领域:
高分子化学
·
胶体与界面化学
·
药物递送系统
·
生物材料
·
纳米医学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 27
·14278-14285
·
IF 8.867
Haibo Tang,Xinlong Tian,Junming Luo,Jianhuang Zeng,Yingwei Li,Huiyu Song,Shijun Liao
Transition metal nitrides have recently attracted significant interest as electrocatalysts for the oxygen reduction reaction (ORR) owing to their low electrical resistance and good corrosion resistance. In this paper, we describe the preparation of a Nb-based binary nitride material with a porous nanogrid morphology/structure. The catalyst exhibited good catalytic activity and high stability towards oxygen reduction. We also intensively investigated the effect that doping with a second transition metal had on the performance of the catalyst. We found that the ORR activity of NbN could be enhanced significantly by enriching the d electrons of Nb through doping with a second transition metal, and that doping with cobalt resulted in the best improvement. Our optimal catalyst, Nb0.95Co0.05N, had an ORR activity ∼4.6 times that of NbN (current density @ 0.6 V vs. the RHE). XPS results revealed that Co doping increased the proportion of Nb in a low-valence state, which may be one of the most important reasons for the enhanced performance. Another important reason is the high surface area resulting from the porous nanogrid morphology. As transition metal doping is an attractive way to enhance the activity of nitride catalysts, our work may provide an effective pathway to achieve this.
研究领域:
材料科学
·
电化学
·
纳米科技
·
催化化学
·
能源材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·Vol. 45
·期 8
·10633-10639
·
IF 3.45
Guorong Hu,Zhichen Xue,Zhongyuan Luo,Zhongdong Peng,Yanbing Cao,Weigang Wang,Yuexi Zeng,Yong Huang,Yong Tao,Tianfan Li,Zhiyong Zhang,Ke Du
The Li-rich cathode material for long cycle performance and long-term storage performance is a challenge for next-generation lithium-ion batteries due to the rapid capacity degradation over cycling and the formation of residual lithium on the surface during long-term storage. Herein, an elevated performance of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 materials via CeO 2 inlay is reported, which was prepared from Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 by sol-gel inlay with CeO 2 . It was proved by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy that cerium oxide cladding not only covered the surface of the material but also diffused into the interior of the material change crystal structure. Cerium oxide on the cladding not only reduces the material's contact with water and carbon dioxide in the air, but also prevents the material from being corroded by electrolyte during electrochemical test. The position of the transition metal atom is replaced Ce atoms, which increases the unit cell volume and the stability of the Li-rich material during the cycling. The results show that the storage property and the electrochemical cycling property of the material have been improved obviously. The CeO 2 inlaid lithium rich material discharged 204.6 mAh/g for the first time at the current of 1C, and 164.4 mAh/g after 150 charge and discharge cycles with corresponding capacity retention rate of 80.35%, compared with the retention rate of 57.26% for pristine Li-rich material capacity. After being stored in humid air for 40 days, the CeO 2 inlaid lithium-rich material showed better electrochemical performance than the pristine one. It is powerfully demonstrated that the CeO 2 inlay strategy here holds huge promise for surface modification of electrode materials for lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
锂离子电池
·
能源存储
·
无机非金属材料
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 26
·2310387
·
IF 13
Wei Luo,Yanli Yu,Yucheng Wu,Wenbin Wang,Yimin Jiang,Wei Shen,Rongxing He,Wei Su,Ming Li
Rational design of heterostructure catalysts through phase engineering strategy plays a critical role in heightening the electrocatalytic performance of catalysts. Herein, a novel amorphous/crystalline (a/c) heterostructure (a-CoS/Ni 3 S 2 ) is manufactured by a facile hydrothermal sulfurization method. Strikingly, the interface coupling between amorphous phase (a-CoS) and crystalline phase (Ni 3 S 2 ) in a-CoS/Ni 3 S 2 is much stronger than that between crystalline phase (c-CoS) and crystalline phase (Ni 3 S 2 ) in crystalline/crystalline (c/c) heterostructure (c-CoS/Ni 3 S 2 ) as control sample, which makes the meta-stable amorphous structure more stable. Meanwhile, a-CoS/Ni 3 S 2 has more S vacancies (S v ) than c-CoS/Ni 3 S 2 because of the presence of an amorphous phase. Eventually, for the oxygen evolution reaction (OER), the a-CoS/Ni 3 S 2 exhibits a significantly lower overpotential of 192 mV at 10 mA cm −2 compared to the c-CoS/Ni 3 S 2 (242 mV). An exceptionally low cell voltage of 1.51 V is required to achieve a current density of 50 mA cm −2 for overall water splitting in the assembled cell (a-CoS/Ni 3 S 2 || Pt/C). Theoretical calculations reveal that more charges transfer from a-CoS to Ni 3 S 2 in a-CoS/Ni 3 S 2 than in c-CoS/Ni 3 S 2 , which promotes the enhancement of OER activity. This work will bring into play a fabrication strategy of a/c catalysts and the understanding of the catalytic mechanism of a/c heterostructures.
研究领域:
材料科学
·
电化学
·
催化化学
·
纳米材料
·
能源材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 23
·12429-12437
·
IF 14.511
Shuang Li,Yunxiang Hou,Di Li,Bo Zou,Qingtang Zhang,Yang Cao,Guodong Tang
SnSe is considered one of the most intriguing new thermoelectric materials. Polycrystalline SnSe offers a wide range of thermoelectric applications due to its facile synthetic processing and machinability. Herein, we have achieved a high average ZT of 0.8 as well as a high peak ZT of 1.86 in solution-synthesized porous Zn and Ga codoped SnSe nanosheets, generating a maximum energy conversion efficiency of 13.3%. High-density micro/nanopores are induced in the SnSe matrix, which are more effective for scattering phonons and reducing the thermal conductivity. The high density of micro/nanopores, nanosheet structure and dislocations contribute to an ultralow lattice thermal conductivity (0.157 W m−1 K−1 at 873 K). Meanwhile, Ga incorporation can induce band convergence and create resonance levels, producing a large Seebeck coefficient. Ga and Zn codoping contributes to a sharp increase in carrier concentration and an obviously increased electrical conductivity. The enhanced Seebeck coefficient and increased carrier concentration help in achieving a significant enhancement of the power factor over a wide temperature range in the porous Zn and Ga codoped SnSe nanosheets. Consequently, high thermoelectric performance is realized over a wide temperature range via the decoupling of electron–phonon transport in SnSe. This work opens up a great opportunity for designing prospective materials for thermoelectric applications with the aid of the solution synthesis route.
研究领域:
材料科学
·
凝聚态物理
·
纳米科技
·
能源材料
·
半导体物理
·
热电转换
·
无机功能材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 9
·4604-4609
·
IF 2.936
Lei Lü,Hongming Lou,Yinglin Xiao,Guangzhao Zhang,Chaoyang Wang,Yonghong Deng
Triblock copolymer polydopamine-polyacrylic-polyoxyethylene (PDA-PAA-PEO) with excellent performance as a binder for silicon anodes was synthesized. Its structure was confirmed by 1H-NMR, FTIR and UV-vis spectroscopy. Results of electrochemical measurements indicated that a silicon anode based on PDA-PAA-PEO binder exhibited excellent cycle performance with a reversible capacity of 1597 mA h g−1 after 200 cycles at a current density of 0.5 C, much better than that of an electrode based on a polyvinylidene-fluoride binder. Improvement of the cycle performance and reversible capacity for silicon anodes could be attributed to the strong adhesive and high ion conductivity of PDA-PAA-PEO.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
纳米材料
·
电池技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 14
·11204-11210
·
IF 3.289
Yawei Sun,Yaopeng Zhang,Jingjing Liu,Fuqiang Nie
In this work, hydrogel photonic crystal beads with inverse opal structure are generated on a well-controlled microfluidic chip device. An online droplet drying method and templating technique are integrated into the producing process. This process results in the silica nanoparticles in the droplets self-assembled into spherical photonic crystals with narrow stop bands and identical structural colours, which is the ideal template for fabricating inverse opal hydrogel beads. The effects of acrylic acid (AA) concentration, water dosage and buffer pH on the equilibrium swelling of inverse opal hydrogel are discussed. In the concentration of AA (3%) and water (31%), the inverse opal hydrogel beads show wide sensing range and rapid response (less than 30 s) to pH variation. Overall, the inverse opal hydrogels as pH sensors show homogeneous structural colour changes due to the spherical 3D structure. The present characterization of quite mechanically robust and good reproducibility for the spherical pH sensor may have promise application in advanced optical devices.
研究领域:
生物医学工程
·
材料科学
·
分析化学
·
微纳制造
·
传感技术
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2020
·
IF 4.652
Jianlong Chai,Yabin Zhu,Zhiguang Wang,Tielong Shen,Yiwen Liu,Lijuan Niu,Shufen Li,Cunfeng Yao,Minghuan Cui,Chao Liu
Al 2 O 3 –ZrO 2 (3Y)–SiC ceramic composites were prepared by spark plasma sintering in vacuum under 40 MPa of uniaxial compression between 1300 °C and 1400 °C. The effect of nano-size SiC and sintering temperature on the microstructure and mechanical properties of ceramic composites were investigated. The results showed that SiC particles was uniformly distributed in the composite, mainly within the matrix grains. Sintering temperature and SiC particles caused the shape of alumina grains to be columnar. The flexural strength of 22.3 vol% Al 2 O 3 -57.7 vol% ZrO 2 -20 vol% SiC sintered at 1350 °C composites was 1081 MPa, fracture toughness was 15.18 MPa m 1/2 and hardness was 16.42 GPa. The addition of SiC particles leads to grain boundary strengthening, and the change of fracture mode and cracks deflection and bridging are considered to be the main reasons for the increase in material fracture toughness.
研究领域:
材料科学
·
陶瓷学
·
复合材料
·
固态物理
·
结构材料
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Naseem Akhtar,Hongyuan Shao,Fei Ai,Yuepeng Guan,Qifan Peng,Hao Zhang,Weikun Wang,Anbang Wang,Bingyin Jiang,Yaqin Huang
Lithium-sulfur (Li-S) batteries with high specific capacity are expected to be a new generation of energy storage devices. However, the shuttle effect of lithium polysulfide makes it difficult to commercialize stable Li-S batteries. In this work, we designed a gelatin-polyethylenimine composite (GPC) as functional binder for Li-S batteries to improve the stability of electrode during discharge-charge process. GPC binder combines the dispersion and adhesion ability of gelatin, which keeps cathode homogeneous and stable during electrochemical reaction , and adsorption capability of PEI for polysulfide , which suppresses the “shuttling effect”. The result shows that GPC used as a binder remarkably enhanced cyclic performance of Li-S battery with good capacity retention of about 100% at current density of 1C (sulfur loading 1.5 mg cm −2 ) after 100 cycles. We believe that GPC would be a promising binder for highly stable Li-S batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
纳米复合材料
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2016
·Vol. 24
·期 2
·863-870
·
IF 3.195
Chen Haizhen,Chen Jing,Teng Na,Na Haining,Zhu Jin
Residual ethanol was used as an activation agent to control the status of corn cellulose (CN cellulose) solution and thereby the morphology of CN cellulose fibers after electrospinning. A suitable amount of ethanol could combine with the CN cellulose chains to reduce their ionic absorbance, improving the migration ability of ions in the cellulose– N , N -dimethylacetamide (DMAc)/LiCl–ethanol system. As a result, the entanglement of the molecular chains of CN cellulose in solution was reduced. Excess ethanol reduced the migration ability of ions and enhanced the strong entanglement of CN cellulose in solution. By thus adjusting the status of the CN cellulose solution, the fiber morphology and diameter distribution after electrospinning could be controlled. Based on the experimental results, this approach represents an important and effective approach using ethanol as an activation and adjusting agent for CN cellulose to achieve formation of high-quality electrospun fibers.
研究领域:
高分子科学
·
材料科学
·
纤维工程
·
生物材料
·
纳米技术
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·Vol. 42
·期 4
·2045-2053
·
IF 3.205
Jing-Jia Zhang,Xu-Lei Sui,Lei Zhao,Li-Mei Zhang,Da-Ming Gu,Zhen-Bo Wang
Molybdenum trioxide (MoO 3 ) has been considered an advanced auxiliary support for Pt nanoparticle anchorage due to its excellent activity and stability. Nevertheless, its non-conductivity property still impedes its applications in electrocatalytic fields. Thus, the MoO 3 and carbon composite of a nanostructure is synthesized through sintering process and served as an efficient co-support for Pt-based anode catalyst in this paper. The electrochemical measurements demonstrate that Pt/MoO 3 -C catalyst shows higher catalytic activity and stability than the as-prepared Pt/C. Significantly, it exhibits 1.95 times higher activity and 2.36 times better durability for methanol oxidation when compared with commercial Pt/C. The remarkably enhanced performance of this novel Pt/MoO 3 -C catalyst for methanol electrooxidation can be ascribed to the abundant Pt nucleation active sites, uniformly dispersed Pt nanoparticles and the strong metal-support interaction between Pt and MoO 3 -C. These outstanding properties suggest Pt/MoO 3 -C a promising catalyst for practical application of fuel cell.
研究领域:
电催化
·
纳米材料
·
能源化学
·
燃料电池
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Qing Cen,Qiaoyuan Gao,Chenlu Zhang,Yingqi Liu,Qi Wang,Qi Wang
In this study, visible-light-active iron tungstosilicate (FeSiW) was fabricated via solvothermal method . Fe 3+ was applied as counter ion to precipitate with silicotungstic acid (H 4 SiW 12 O 40 ) in methanol solution. It can be observed from FT-IR spectra that the Keggin structure of SiW 12 O 40 4− was well maintained in FeSiW. Besides, the effect of different initial molar ratios of Fe 3+ to H 4 SiW 12 O 40 was investigated (from 4:1 to 4:4). By photoelectrochemical characterizations, such as photocurrent response and Mott-Schottky (M-S) plots, easiest generation of electron-hole pairs and lowest charge transfer resistance can be observed on FeSiW with initial molar ratio of 4:3. Moreover, FeSiW with 4:3 ratio also displayed highest activity for photocatalytic reduction of Cr(VI), despite of the largest band gap (ca. 2.71 eV). The lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) of the optimized FeSiW were estimated to be +0.03 V and 2.74 V vs NHE, respectively, which were thermodynamically feasible for Cr(VI) reduction and H 2 O oxidation . Even under acidic condition (pH 3), the optimized photocatalyst displayed good stability in cyclic runs. Therefore, the present study opens a new way for heterogeneous polyoxometalates as efficient photocatalyst for environmental application.
研究领域:
环境化学
·
材料科学
·
光催化
·
无机化学
·
污染治理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）