Development Strategies in Transition Metal Borides for Electrochemical Water Splitting

Electrochemical water splitting is a feasible method for producing environmental benignity energy of hydrogen, while high price and low availability on the earth of noble electrocatalysts constrain their global‐scale application. Transition metal borides (TMBs) have displayed unique metalloid characteristic and outstanding performance for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in the last few decades. Herein, recent developments of the TMBs for HER and OER are summarized. Initially, the impact factors and relevant evaluation of electrocatalytic performance are described, that is, overpotential, Tafel slope and exchange current density, stability, faradaic efficiency, turnover frequency, mass and specific activities. Moreover, the optimization strategies of borides are emphasized, which principally include coupling with effective substrates, elemental doping, phase modification, interfacial engineering, and morphology control. Finally, in order to reach the goal of application, the remaining challenges and perspectives are given to point out a direction for enhancing the performance of borides.