Enhanced photocatalytic activity of β-Ga₂O₃ nanowires by Au nanoparticles decoration

Combining plasmonic noble metals with semiconductor materials has been considered to be an effective way to improve catalyst performance. In the present paper, Au nanoparticles (NPs) were decorated onto CVD-grown β-Ga₂O₃ nanowires (NWs) through a chemical reduction method. Different quantity of HAuCl₄ solution was used to control the size and density of Au NPs. The photocatalytic activity of the Au–Ga₂O₃ NWs is evaluated by degrading rhodamine B (Rh B) under UV and visible light irradiation. It is found that the size and density of the Au NPs had a great influence on the photocatalytic efficiency of β-Ga₂O₃ NWs. And Ga₂O₃ NWs with Au NPs of ~ 5.7 nm size and ~ 420/μm² density shows the best catalytic efficiency. Moreover, Au NPs attachment on the Ga₂O₃ could extend its photocatalytic activity towards the visible light irradiation, which is significant to efficient utilization more solar light. A jointly effect of both the interfacial Schottky potential field between Au NPs and β-Ga₂O₃ NWs and local surface plasma resonance excitation is proposed to contribute the enhancement effects.