Few-layered WSe2 nanoflowers anchored on graphene nanosheets: a highly efficient and stable electrocatalyst for hydrogen evolution

Tungsten selenide (WSe2) has emerged as a promising electrocatalyst for hydrogen evolution reaction (HER), and its HER performance strongly depends on its conductivity and exposed edge sites. Herein, a RGO/WSe2 hybrid network constructed with few-layered WSe2 nanoflowers anchored on graphene nanosheets has been synthesized through a facile one-pot solvothermal method. Compared with bare WSe2 nanoflowers with relatively poor HER performance, the RGO/WSe2 hybrid demonstrates a highly effective and stable electrocatalytic performance: it delivers a small Tafel slope of 57.6 mV dec(-1), a remarkably low onset potential of similar to 150 mV, a high current density of 38.43 mA cm(-2) at 300 mV vs RHE and excellent long-term stability. The superior HER performance of RGO/WSe2 hybrid is attributed to the unique WSe2-anchored-on-graphene structure, which ensures the robust contact between the fewlayered WSe2-nanoflowers catalyst and the highly conductive graphene matrix, leading to enhance the charge transfer kinetics between the catalytic edge sites and the graphene nanosheets. Therefore, the RGO/WSe2 hybrid is promising as high-performance catalysts for hydrogen evolution applications. (C) 2016 Elsevier Ltd. All rights reserved.