Fabrication of Hollow CoP/TiOx Heterostructures for Enhanced Oxygen Evolution Reaction

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/TiOx heterostructure. The CoP/TiOx heterostructure is fabricated using metal–organic framework nanocrystals as templates, which leads to unique hollow structures and uniformly distributed CoP nanoparticles on TiOx. The strong interactions between CoP and TiOx in the CoP/TiOx heterostructure and the conductive nature of TiOx with Ti3+ sites endow the CoP–TiOx hybrid material with high OER activity comparable to the state‐of‐the‐art IrO2 or RuO2 OER electrocatalysts. In combination with theoretical calculations, this work reveals that the formation of CoP/TiOx heterostructure can generate a pathway for facile electron transport and optimize the water adsorption energy, thus promoting the OER electrocatalysis. Hybrid materials are promising functional materials for energy storage and conversion applications owing to the combined advantages/features and the synergistic effect. Herein, enhanced electrocatalytic oxygen evolution reaction (OER) performance of CoP is achieved by constructing a hybrid CoP/TiOx heterostructure. The synergistic effect between CoP and TiOx for the enhanced electrocatalytic OER performance is explored both experimentally and theoretically.