Fabrication of Hollow CoP/TiO<i>_x</i> Heterostructures for Enhanced Oxygen Evolution Reaction

Abstract

Abstract Transition‐metal phosphides have flourished as promising candidates for oxygen evolution reaction (OER) electrocatalysts. Herein, it is demonstrated that the electrocatalytic OER performance of CoP can be greatly improved by constructing a hybrid CoP/TiO x heterostructure. The CoP/TiO x heterostructure is fabricated using metal–organic framework nanocrystals as templates, which leads to unique hollow structures and uniformly distributed CoP nanoparticles on TiO x . The strong interactions between CoP and TiO x in the CoP/TiO x heterostructure and the conductive nature of TiO x with Ti 3+ sites endow the CoP–TiO x hybrid material with high OER activity comparable to the state‐of‐the‐art IrO 2 or RuO 2 OER electrocatalysts. In combination with theoretical calculations, this work reveals that the formation of CoP/TiO x heterostructure can generate a pathway for facile electron transport and optimize the water adsorption energy, thus promoting the OER electrocatalysis.