Theoretical Revelation and Experimental Verification Synergistic Electronic Interaction of V-Doped RuNi as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting

As an advanced technology in the preparation of a sustainable and clean hydrogen energy source, electrolysis of water splitting has attracted more and more research attention. Water electrolysis is an important step toward hydrogen economy on account of the high efficiency and environmentally friendly. However, developing bifunctional electrocatalysts possessed with low cost, high activity, and everlasting durability to simultaneously promote bulk water cleavage is imminent. In this work, transition metal oxide (TMOs) HxV2O5 was anchored on the RuNi bimetallic catalyst by hydrothermal method to form a porous granular catalyst, which greatly improved the electron transfer ability. Due to the increased contact surface between RuVONi and electrolyte of this structural catalyst, the amounts of active sites are ferreted out. In-depth experimental results and DFT calculations show optimized molar ratio RuNiVO sample has superior electron transport ability compared with RuNiV, RuNiMoO, and RuNiMo, and exhibits significant electrocatalytic performance at 1.0 M KOH. Under the current density of 10 mA cm–2, RuNiVO electrocatalysts show OER and HER overpotentials of 224 and 136 mV and have superior durability. The density functional theory (DFT) results indicate that the insertion V metal oxide may optimize ΔG with higher charge density intensity, thereby improving its OER and HER activities.