WS2 Nanosheets with Highly-Enhanced Electrochemical Activity by Facile Control of Sulfur Vacancies

Zhu, Qing1; Chen, Wenzhou1; Cheng, Hua2; Lu, Zhouguang2; Pan, Hui1,3

2019-06-06

10.1002/cctc.201900341

ChemCatChem   影响因子和分区

1867-3880

1867-3899

Tungsten disulfide (WS2) is a promising and low-cost material for electrochemical hydrogen evolution reaction (HER) and has been extensively studied due to its excellent performance. However, the development of a facile and controllable defect-engineering to activate its basal planes is still crucial to improve its HER activity. Here, we put forward an annealing strategy to create controllable sulfur vacancies (S-vacancies) in ultrathin WS2 nanosheets, which can result in the increase of active sites and enhanced electrocatalytic activity accordingly. Our density-functional-theory (DFT) calculations reveal that the Gibbs free energy of hydrogen adsorption (Delta G(H*)) can be tuned to near zero by controlling the density of S-vacancies, leading to thermal-neutral HER performance. We find that optimal HER performance can be achieved by tuning the density of S-vacancies in WS2 through annealing in the mixture of Ar and H-2 (5 %). The WS2 nanosheets with the optimal density of S-vacancies show lower overpotential by 116 mV at 10 mA/cm(2) and smaller Tafel slope by 37.9 mV/dec than as-prepared counterpart, and super-excellent stability in acid. Additionally, the WS2 with optimal S-vacancies also shows the best HER activity in alkaline solution. Our findings present a facile and general strategy to design electrocatalysts with more active sites, which is applicable to other materials for the improvement of their catalytic activities.

WS2 nanosheets sulfur vacancy electrocatalyst hydrogen evolution reaction annealing DFT calculation

SCI ; EI

英语

其他

Shenzhen Peacock Plan[KQTD2016022620054656]

Chemistry

Chemistry, Physical

WOS:000470937300013

WILEY-V C H VERLAG GMBH

20192106965141

Annealing ; Catalyst activity ; Density functional theory ; Design for testability ; Electrocatalysts ; Free energy ; Gas adsorption ; Gibbs free energy ; Nanosheets ; Slope stability ; Sulfur ; Sulfur compounds

Roads and Streets:406.2 ; Heat Treatment Processes:537.1 ; Thermodynamics:641.1 ; Nanotechnology:761 ; Chemical Operations:802.3 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804 ; Probability Theory:922.1 ; Solid State Physics:933

Web of Science

1.Univ Macau, Inst Appl Phys & Mat Engn, Minist Educ, Joint Key Lab, Macau 999078, Sar, Peoples R China
2.Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Guangdong, Peoples R China
3.Univ Macau, Fac Sci & Technol, Dept Phys & Chem, Macau 999078, Sar, Peoples R China

Zhu, Qing,Chen, Wenzhou,Cheng, Hua,et al. WS2 Nanosheets with Highly-Enhanced Electrochemical Activity by Facile Control of Sulfur Vacancies[J]. ChemCatChem,2019,11(11):2667-2675.

Zhu, Qing,Chen, Wenzhou,Cheng, Hua,Lu, Zhouguang,&Pan, Hui.(2019).WS2 Nanosheets with Highly-Enhanced Electrochemical Activity by Facile Control of Sulfur Vacancies.ChemCatChem,11(11),2667-2675.

Zhu, Qing,et al."WS2 Nanosheets with Highly-Enhanced Electrochemical Activity by Facile Control of Sulfur Vacancies".ChemCatChem 11.11(2019):2667-2675.