Wettability control in electrocatalyst: A mini review

Electrocatalysis, as a typical heterogeneous catalysis, generally occurs in the di- or tri-phase interfaces. Wettability is an important property for describing the balance of a gas-liquid-solid system. Therefore, the wettability of reaction interface, especially hydrophilicity/hydrophobicity, plays an important role in the adsorption/desorption process of gas bubbles on the surface of the solid electrode. Herein, we present a comprehensive review of the wettability control of the electrode materials applied in electrocatalysis reactions, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR). Firstly, the basic theories of wettability as well as the impact on electrocatalysis were introduced in this review. Secondly, the overview of modifying methods of the wettability from electrocatalyst microstructure (structural modification, surface coating, introducing hydrophilic groups) and system design (electrode, device) were suggested. At last, the deficiencies and problems in the application of wettability control are discussed, and deeper and broader application prospects are proposed.