Novel CoxSy/WS2 nanosheets supported on carbon cloth as efficient electrocatalyst for hydrogen evolution reaction

To maximum the activity of transition metal sulfides for hydrogen evolution reaction (HER), two strategies usually have been adopted including designing unique nanostructures and integrating other metal element. Herein, CoxSy/WS2 nanosheets supported on carbon cloth (CoxSy/WS2/CC) have been fabricated via a facile hydrothermal process. The cross-linked structures composed of CoxSy/WS2 nanosheets uniformly cover on the surface of CC, which may expose abundant active sites for HER and accelerate charge transfer rate. The molar ratio of CoxSy-incorporating has been investigated in detail. The molar ratio of W/Co = 1/3 (noted as CoxSy/WS2/CC-3) has been proved to have unique spherical CoxSy/WS2 nanostructure, which may further expose more active sites for HER. Electrochemical measurements demonstrate that CoxSy-incorporating can enhance HER activity and conductivity compared with WS2/CC. In addition, CoxSy/WS2/CC-3 exhibits the best HER activity, smallest charge transfer resistance and excellent stability than the counterparts, implying that the degree of CoxSy-incorporating may impact the HER activity of WS2. The mechanisms of CoxSy-incorporating on enhancing HER activity of WS2 have been discussed. It may offer a promising way to design transition metal sulfides-based electrocatalysts for HER by non-precious metal incorporating.