Visible light-excited surface plasmon resonance charge transfer significantly improves the photocatalytic activities ofZnOsemiconductor for pollutants degradation

To effectively address environmental pollution, we synthesized Au-loaded ZnO nanocomposites and applied for the photocatalytic degradation of 2-chlorophenol (2-CP) under visible light irradiation. The as-prepared nanophotocatalysts delivered much improved photocatalytic degradation activities as compared to the bare ZnO nanoparticles and 32% of the pollutant was degraded with 2AuZnO in 1 hr. These improved photoactivities are attributed to the extended visible light absorption due to the surface plasmon resonance property of the loaded Au nanoparticles. Moreover, Au nanoparticles played important role in charge separation by inducting excited electrons to the conduction band of ZnO photocatalyst and surface catalysis as confirmed from photoluminescence spectra and amount of the generated hydroxyl radicals. The trapping experiments confirmed that positive holes were the major degrading species during the photocatalytic degradation of 2-CP. This work provides a feasible way to improve the photocatalysis by introducing a proper amount of noble metals over the surface of semiconductor photocatalysts.