Metallic Pt and PtO2 Dual-Cocatalyst-Loaded Binary Composite RGO-CNx for the Photocatalytic Production of Hydrogen and Hydrogen Peroxide

Photocatalytic overall water splitting is considered as an ideal solution to the energy crisis by converting inexhaustible solar energy into hydrogen energy. However, the practical application of photocatalytic overall water splitting is hindered by the challenges including unfavorable four-electron/hole kinetics and H2/O2 separation. Here, the binary composite of reduced graphene oxide and graphitic carbon nitride decorated by the double cocatalyst (Pt and PtO2) is reported to achieve excellent photocatalytic water reforming performance for H2 and H2O2 production via the two-electron pathway. In addition, a unique structure with Pt and PtO2 as active sites for reduction and oxidation, respectively, is further proposed. This unique structure promotes the separation of photogenerated carriers and holes, extends the light absorption, and thus significantly improves photocatalytic activity with the highest H2 evolution rate of 5.7 μmol·h–1. What's more, the addition of reduced graphene oxide can improve the photocatalytic stability of the catalyst by reinforcing the chemical connection between graphitic carbon nitride and PtOx (Pt, PtO2). This work highlights the important role of using graphitic carbon nitride for heterogeneous catalysis and reveals the possibility of designing multiple components to realize an efficient photocatalytic water reforming.