In situ growth of Au nanoparticles on 3D Bi2O2CO3 for surface plasmon enhanced visible light photocatalysis

Abstract

Novel plasmonic photocatalysts were fabricated by the modification of 3D Bi₂O₂CO₃ microspheres with Au nanoparticles (NPs) via a facile one-pot in situ method for the first time. The as-obtained 3D Au/Bi₂O₂CO₃ heterostructures (Au/BOC) were characterized by XRD, XPS, SEM, TEM, EDX, N₂ adsorption–desorption isotherms, UV-vis DRS and PL. The results revealed that the Au NPs were produced by in situ reduction of Au³⁺ by the citrate ions and deposited on the surface of Bi₂O₂CO₃ microspheres. The photocatalytic activity of Au/BOC was evaluated by the removal of NO under visible light with pure Bi₂O₂CO₃ as reference. The pure Bi₂O₂CO₃ microspheres displayed decent photocatalytic activity due to surface scattering and reflecting (SSR) that resulted from their special hierarchical architecture. Au/BOC exhibited highly enhanced visible light photocatalytic performance in comparison with pure BOC because of the co-contribution of the SSR effect, the Schottky barrier and the surface plasmon resonance (SPR) effect endowed with metallic Au NPs. The integration of the SSR effect and SPR effect in one system for enhancing photocatalysis could provide a new scope in the architectural design and mechanistic understanding of other noble metal-based plasmonic photocatalysts.