Noble-metal-free tungsten oxide/carbon (WO_x/C) hybrid manowires for highly efficient hydrogen evolution

Developing active, stable, and low-cost electrocatalysts to generate hydrogen is a great challenge in the fields of chemistry and energy. Nonprecious metal catalysts comprised of inexpensive and earth-abundant transition metals are regarded as a promising substitute for noble metal catalysts used in hydrogen evolution reaction (HER), but are still practically unfeasible mainly due to unsatisfactory activity and durability. Here we report a facile two-step preparation method for WO_x nanowires with high concentration of oxygen vacancies (OVs) via calcination of W-polydopamine compound precursors. The resulting hybrid material possesses a uniform and ultralong 1D nanowires structure and a rough and raised surface, which can effectively improve the specific surface area. The products exhibit excellent performance for H₂ generation: the required overpotentials for 1 and 10 mA cm^-2 are 18 and 108 mV, the Tafel slope is 46 mV/decade, and the electrochemically active surface area is estimated to be ∼77.0 m² g^-1. After 1000 cycles, the catalyst works well without significant current density drop. Our experimental results verified metallic transition metal oxides as superior non-Pt electrocatalysts for practical hydrogen evolution reactions.