Ag–Pt bimetallic composite supported on defective C3N nanosheets for plasmon hot electron-mediated photocatalytic H2 evolution

Combining the strong localized surface plasmon resonance (LSPR) of metallic Ag and the chemically reactive Pt co-catalyst, the Ag–Pt bimetallic composite was prepared and then coated on the surface of the exfoliated defective graphitic carbon nitride nanosheets (C3Nx NS) for plasmon hot electron-mediated photocatalytic H2 evolution. Under the visible light irradiation, the sample of (1:2) Ag–Pt/C3Nx NS exhibits the highest activity (1.25 mmol g−1 h−1), which is 35.7 and 1.7 times higher than that of Ag/C3Nx NS and Pt/C3Nx NS, respectively. Moreover, the apparent quantum efficiency (AQE) of (1:2) Ag–Pt/C3Nx NS reaches 3.3% at 420 nm. The boosted photocatalytic capacity may be ascribed to the utilization of the advantages of the LSPR effect of Ag particles and the Schottky barrier between Pt and C3Nx NS, resulting in more electrons participate in the reduction reaction to boost the photocatalytic H2 evolution performance.