摘要
Seeking more economical alternative electrocatalysts without sacrificing much in performance to replace precious metal Pt is one of the major research topics in hydrogen evolution reactions (HER). Tungsten disulfide (WS 2 ) has been recognized as a promising substitute for Pt owing to its high efficiency and low-cost. Since most existing works adopt solution-synthesized WS 2 crystallites for HER, direct growth of WS 2 layered materials on conducting substrates should offer new opportunities. The growth of WS 2 by the thermolysis of ammonium tetrathiotungstate (NH 4 ) 2 WS 4 was examined under various gaseous environments. Structural analysis and electrochemical studies show that the H 2 S environment leads to the WS 2 catalysts with superior HER performance with an extremely low overpotential (η10 = 184 mV).