Electrochemically Inert g‐C3N4 Promotes Water Oxidation Catalysis

Abstract

AbstractElectrode surface wettability is critically important for heterogeneous electrochemical reactions taking place in aqueous and nonaqueous media. Herein, electrochemically inert g‐C3N4 (GCN) is successfully demonstrated to significantly enhance water oxidation by constructing a superhydrophilic catalyst surface and promoting substantial exposure of active sites. As a proof‐of‐concept application, superhydrophilic GCN/Ni(OH)2 (GCNN) hybrids with monodispersed Ni(OH)2 nanoplates strongly anchored on GCN are synthesized for enhanced water oxidation catalysis. Owing to the superhydrophilicity of functionalized GCN, the surface wettability of GCNN (contact angle 0°) is substantially improved as compared with bare Ni(OH)2 (contact angle 21°). Besides, GCN nanosheets can effectively suppress Ni(OH)2 aggregation to help expose more active sites. Benefiting from the well‐defined catalyst surface, the optimal GCNN hybrid shows significantly enhanced electrochemical performance over bare Ni(OH)2 nanosheets, although GCN is electrochemically inert. In addition, similar catalytic performance promotion resulting from wettability improvement induced by incorporation of hydrophilic GCN is also successfully demonstrated on Co(OH)2. The present results demonstrate that, in addition to developing new catalysts, building efficient surface chemistry is also vital to achieve extraordinary water oxidation performance.