Understanding the Enhanced Electrocatalytic Hydrogen Evolution via Integrating Electrochemically Inactive g‑C3N4: The Effect of Interfacial Engineering

Electrocatalytic water splitting is a very promising hydrogen generation technology, and nonprecious electrocatalysts with outstanding performance are highly desired for future applications. Interfacial engineering, creating abundant interfaces with active sites when combining different materials, is of critical importance to not only modify the local structure of the electrocatalysts but also modulate the catalytic kinetics during the electrocatalytic reaction, thus offering a promising route toward unexpected electrocatalytic activity. Herein, graphitic carbon nitride (g-CN), which is electrochemically inert, is decorated onto the molybdenum disulphide (MoS2) surface to construct a MoS2/g-CN heterogeneous structure via a simple hydrothermal method. After integrating g-CN, an enlarged surface area, interfacial charge redistribution, and moderate surface-hydrogen adsorption are achieved without affecting the MoS2 morphology. Consequently, the MoS2/g-CN heterostructure exhibits a comparable electrocatalytic activity: a Tafel slope of 57 mV dec–1 and an overpotential of 141 mV at 10 mA cm–2. This work indicates the importance of interfacial engineering as an effective strategy for the rational design of electrocatalysts.