Interfacial synergistic effect of Ru nanoparticles embedded onto amorphous/crystalline WO3 nanorods on boosting the pH-universal hydrogen evolution reaction

The development of high-efficiency pH-universal electrocatalyst is of great significance for hydrogen evolution reaction (HER). In this work, a rod-like Ru/WO3-VO electrocatalyst was constructed for HER via a solid-phase reaction strategy. Due to the restriction of atomic migration at solid phase interface, plenty of oxygen vacancies (VO) and structure distortions were generated in amorphous/crystalline WO3 phase (WO3-VO). The optimized Ru/WO3-VO annealed at 450 oC with 2.2 wt% Ru achieves outstanding intrinsic activity with low overpotential and Tafel slope in a 0-14 pH range. A turnover frequency value 7.2 higher than that of commercial Pt/C is abtaind on Ru/WO3-VO at overpotential of 100 mV. Density functional theory calculations reveal that H* adsorption and desorption balanced by tuning the interface electronic structure contributes synergistic effect to the pH-universal HER activity of Ru/WO3-VO. The crystalline/amorphous semiconductor-metal heterointerface is crucial to designing and synthesizing electrocatalysts for optimal HER activity.