Growth of nano Ag@AgCl on (111) facets of Cu2O microcrystals with an enhanced photocatalytic activity

Abstract

Single crystalline Cu₂O nanoparticles were synthesized under mild conditions. A Ag@AgCl/Cu₂O photocatalyst was prepared by directly growing Ag@AgCl nanoparticles (NPs) on (111) facets of octahedral Cu₂O via a facile precipitation in situ photoreduction method. The results indicate that Ag@AgCl nanoparticles have a narrow size distribution ranging from 10 to 50 nm and are uniformly distributed on the surface of Cu₂O nanoparticles. The surface area of the composite reached up to 19.736 m² g⁻¹. The photocatalytic performance of the Ag@AgCl/Cu₂O composite for the degradation of methylene blue (MB) was evaluated under visible light irradiation. The Ag@AgCl/Cu₂O composite with 30 wt% Ag@AgCl showed the highest photocatalytic activity, degrading 93.61% MB after 2 h irradiation. The high photocatalytic activity of the Ag@AgCl/Cu₂O composite can be attributed to its high surface area, the crystal effect of Cu₂O and the surface plasmon resonance of the Ag NPs. In addition, the Ag@AgCl/Cu₂O composite can be used as a photocatalyst for the degradation of phenol. Based on these experimental results, a photocatalytic mechanism for the degradation of hazardous chemical effluents over Ag@AgCl/Cu₂O photocatalysts was proposed. The free radicals and holes act as the main reactive species during the degradation.