Superhydrophilic and Superaerophobic Copper Phosphide Microsheets for Efficient Electrocatalytic Hydrogen and Oxygen Evolution

Bifunctional, binder‐free, and non‐precious‐metal electrocatalysts with superwetting properties are of great significance for high‐performance oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). Herein, the fabrication of copper phosphide (Cu 3 P) microsheets through the phosphidation of CuCl microsheets deposited onto nickel foam, and the effective catalytic activity of the Cu 3 P microsheets in the HER and OER is demonstrated. Due to their hierarchical structure, the Cu 3 P microsheets are superhydrophilic and superaerophobic. A well‐defined superhydrophilic surface enhances the electrolyte–electrode contact, and a superaerophobic surface facilitates bubbles extraction and efficiently minimizes the dead area of the electrode induced by bubble coverage. These two features are beneficial for the high activity and stability of the electrocatalysts during the OER and HER. The superhydrophilic and superaerophobic Cu 3 P microsheets prepared at 450 °C afford a current density of 10 mA cm –2 at an overpotential of 290 mV for the OER and 130 mV for the HER. This work highlights a simple, low‐cost approach that can be easily scaled‐up to construct high‐performance electrocatalysts for the OER and HER.