Oxidized carbon fiber supported vertical WS2 nanosheets arrays as efficient 3 D nanostructure electrocatalyts for hydrogen evolution reaction

Oxidized carbon fiber (oCF) as support successfully realizes the vertical growth of uniform WS 2 nanosheets arrays for efficient hydrogen evolution reaction (HER) via a facile hydrothermal process. Thanks to oxygen functional groups on oCF, vertical WS 2 nanosheets structures have grown more easily on oCF, which can provide better dispersion, short charge transfer distance and more exposed active sites for HER in comparison with bulk WS 2 and WS 2 nanosheets on bare carbon fiber (CF) fabricated at the same condition. The electrochemical measurements confirmed that WS 2 /oCF possesses better HER activity than bulk WS 2 and WS 2 /CF. Especially, the 10-h stability with unchanged vertical WS 2 nanosheets morphology further demonstrate the positive effect of oxygen functional groups on the enhanced vertical structure and close combination between WS 2 and oCF. It may offer a facile way to realize more exposed active sites from stable electrocatalyst hybrids of transition metal sulfides by surface oxidization of carbon supports.