ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
M.Y. Gao,C. Yang,Q.B. Zhang,Y.W. Yu,Y.X. Hua,Y. Li,P. Dong
Porous Ni-Cu alloy films composed of nanosheets are directly fabricated on Cu substrate using a facile potentiostatic electrodeposition approach from a 1:2 choline chloride-ethylene glycol eutectic solvent (ethaline) containing nickel chloride and copper chloride. Electrochemical co-deposition of Ni-Cu alloy in ethaline is found to be thermodynamically favorable in comparison to conventional aqueous solutions. The deposition process occurs via an instantaneous nucleation and growth of nanoparticles at the initial stage and develops vertically to form nanoporous structures arrayed with nanosheets over deposition time . The as-prepared porous Ni-Cu alloy nanosheet arrays exhibit enhanced electrocatalytic activity for the hydrogen evolution reaction (HER) in alkaline media , which displays a small Tafel slope of 57.2 mV dec −1 with a low onset potential of −48 mV vs. RHE at an optimal condition. It requires small overpotentials of −128 and −150 mV to drive catalytic current densities of 10 and 20 mA cm −2 , respectively. This facile electrodeposition method performed in ethaline provides an efficient way to fabricate porous Ni-based alloy nanosheets directly on a current collector, which is a promising technology for the synthesis of earth-abundant HER electrocatalysts .
研究领域:
电催化
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材料科学
·
能源化学
·
纳米材料
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2018
·Vol. 5
·期 15
·1800515
·
IF 4.834
Lingxia Zheng,Wangwang Hu,Xuwei Shu,Huajun Zheng,Xiaosheng Fang
Cobalt phosphides based materials are considered as promising electrocatalysts for the hydrogen evolution reaction (HER). The catalytic performance can be further enhanced by improving the intrinsic catalytic activity, exposing more active sites and coupling with conductive support. Herein, a novel electrocatalyst based on nitrogen doped reduced graphene oxides decorates with uniformly distributed CoP x nanoparticles with a suitable P/Co ratio ( x = 1.7) via a facile and mild condition. The optimized composite (CoP x /N-rGO) exhibits superior electrocatalytic HER activities with a low overpotential of 104 mV (at 10 mA cm −2 ), a small Tafel slope of 65 mV dec −1 , and long-term stability in the alkaline media, comparable to the performance of other HER electrocatalysts. The remarkable HER performance can be ascribed to the good electrical conductivity of rGO and extra active sites created by nitrogen doping. In addition, the ultrafine nanostructure (average particle size ≈4 nm) and well-dispersed CoP x nanoparticles also help expose more active sites for electrocatalytic reactions, largely hindering the agglomeration and exfoliation. This work provides a versatile route on the design of multifunctional composite materials for renewable energy research with low cost and high activity.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Mingyuan Chen,Yaxin Lv,Peilin Wu,Liuyan Dong,Xingquan He,Lili Cui
To obtain highly active electrocatalyst for the whole electrochemical water splitting is of importance to generate hydrogen. Co(OH) 2 is used as electrocatalyst towards OER, however, the performance can be improved further. Usually, to construct the interface and adjust the electronic environment of electrocatalysts are regarded as powerful ways to improve the activity. Herein, CeO 2 -Co(OH) 2 sheets supported on copper foam (CF) are fabricated by electrodeposition method. The morphology and the electron structure of metals are adjusted by changing the molar ratio of Co to Ce, thus, resulting in different electrocatalytic activity. The optimal hybrids of CeO 2 -Co(OH) 2 exhibits lower overpotentials of 188, 269 mV to reach 10 mA cm −2 towards HER and OER, respectively, and good stability. Notably, it is found that the electroactivity is extremely superior to that of bare CF as well as the counterparts in the literature. Also, we try to employ M(OH) 2 (M = Fe, Ni) to substitute Co(OH) 2 to investigate the effect of species of hydroxides on the electron interaction between CeO 2 and hydroxides, the XPS results indicate that Ce and Co shows stronger electron interaction compared to other two control hydroxides. As electrocatalysts for alkaline full water splitting, CeO 2 -Co(OH) 2 requires a cell voltage of 1.62 V to drive 10 mA cm −2 . Experimental results prove the advantages of the electron engineering and morphology control.
研究领域:
材料科学
·
电化学
·
能源化学
·
纳米材料
·
催化化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
K. Huang,K. Bi,J.C. Xu,C. Liang,S. Lin,W.J. Wang,T.Z. Yang,Y.X. Du,R. Zhang,H.J. Yang,D.Y. Fan,Y.G. Wang,M. Lei
Novel nanocomposites of spherical graphite-carbon encased tungsten carbide (GC-WC) are synthesized by solid state reaction with melamine and WO 3 as precursors under N 2 atmosphere. The diameters of the GC-WC composites range from 50 to 200 nm and the WC nanoparticles inside with an average size of ca. 15 nm distribute uniformly. The characterization results indicate that the GC-WC is composed of few layers of graphite carbon and WC nanoparticles with high crystallization and purity. Moreover, the electrocatalytic performance of GC-WC for the oxygen reduction reaction (ORR) in alkaline medium is further investigated by cyclic voltammetry (CV), rotating disk electrode (RDE) and chronoamperometry test with or without 3 M methanol. The results show that GC-WC has a considerable performance for ORR in the view of activity, stability and methanol tolerance, which may further used as proper supports for noble-metal based ORR catalysts in alkaline fuel cell . The synergetic interaction between the carbide nanoparticles and graphite carbon, which means that the surface graphite carbon layers are activated by WC nanoparticles for ORR and in turn protect inner WC from highly oxidizing environments has also been verified.
研究领域:
材料科学
·
纳米科技
·
电化学
·
能源材料
·
催化化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Xiaozhen Chen,Ji Qi,Pan Wang,Chuang Li,Xiao Chen,Changhai Liang
Herein, PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness are synthesized via a polyvinyl alcohol (PVA) involved approach and used for hydrogen evolution reaction (HER). The average crystallite size of the PVA protected nMo 2 CN nanospheres (6.1 nm) is one third of that of the PVA-Mo 2 C/Mo 2 N without PVA protection (17.9 nm). At 10 mA cm −2 current density, the as-synthesized PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness exhibit HER overpotentials of 132 mV and 142 mV with corresponding Tafel slope of 51.8 mV dec −1 and 50.4 mV dec −1 in acid and alkaline medium, respectively. This high apparent activity can be attributed to the high intrinsic activity originated from the adjacent surface active sites of Mo 2 C and Mo 2 N as well as the large ECSA of PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源化学
·
表面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Kai-Wen Cao,Hao Huang,Fu-Min Li,Hong-Chang Yao,Juan Bai,Pei Chen,Pu-Jun Jin,Zi-Wei Deng,Jing-Hui Zeng,Yu Chen
The reactive and stable catalysts for the oxygen reduction reaction are highly desirable for low temperature fuel cells. The commercial oxygen reduction reaction electrocatalysts generally reply on noble metal based nanomaterials, which suffer from inherent cost and selectivity issues. At present, it still remains challenge for designing efficient non-noble metal-based oxygen reduction reaction electrocatalysts. Herein, we successfully synthesize Co nanoparticles supported on three-dimensionally N-doped holey graphene aerogels hybrids by the high-temperature calcination of the graphene aerogels-polyallylamine-Co II hybrids. The component optimized hybrids show the excellent electrocatalytic activity for oxygen reduction reaction in alkaline media, which is comparable to commercial Pt/C electrocatalyst. Meanwhile, the hybrids also show eminent tolerance for CO and methanol, attributing to their excellent oxygen reduction reaction selectivity. The three-dimensionally interconnected structure of graphene aerogels, N-doping, uniform dispersion and high crystallinity of Co nanoparticles, and holey structure of graphene contribute to the striking oxygen reduction reaction activity of hybrids.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
燃料电池
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）