Ultrathin WS2 nanosheets vertically aligned on TiO2 nanobelts as efficient alkaline hydrogen evolution electrocatalyst

Highly efficient and durable non-noble metal-based hydrogen evolution electrocatalysts are critical to advance the production of hydrogen energy via alkaline water electrolysis . Herein, we prepared a novel TiO 2 @WS 2 hybrid via a facile and scalable two-step hydrothermal strategy combined with selective etching. Benefited from acid-etched TiO 2 nanobelts with rough surface as substrate, ultrathin WS 2 nanosheets nucleated and vertically grew into few layers in the confined configuration with more exposed active edges. Furthermore, the partial incorporation of oxygen in WS 2 inherited from the remaining O–W bonds of tungsten precursor enhanced the electrical conductivity of the hybrid. Therefore, TiO 2 @WS 2 hybrid was proved to be efficient and durable electrocatalyst for hydrogen evolution in alkaline medium . Upon optimal conditions, the hybrid only required a small onset overpotential of 95 mV and a low overpotential of 142 mV at 10 mA cm −2 , superior to pristine WS 2 and TiO 2 . In addition, better cycling stability during the alkaline HER process was also obtained, indicating its capability in future practical application. The synthesis strategy presents a cost-effective approach to produce efficient WS 2 -based HER electrocatalyst for electrochemical water splitting.