Enhanced photocatalytic activity of a flower-like In2O3/ZnGa2O4:Cr heterojunction composite with long persisting luminescence

Abstract

The development of new photocatalysts with high photocatalytic efficiency and catalytic stability, and long persisting luminescence is critical for ensuring environmental protection and clean energy production. In this study, we develop a flower-like In₂O₃/ZnGa₂O₄:Cr heterojunction composite with enhanced ultraviolet (UV) photocatalytic activity using a facile two-step hydrothermal method. The spectral response range of the heterojunction composite is widened to the visible-light range owing to the presence of the ZnGa₂O₄:Cr persistent luminescence nanoparticles with sizes of less than 10 nm. The heterojunction composite is dispersed on the flower petals of In₂O₃. The In₂O₃/ZnGa₂O₄:Cr/1:1 composite exhibits photo-degradation performance for rhodamine B degradation that is superior to those of pure In₂O₃, ZnGa₂O₄:Cr, In₂O₃/ZnGa₂O₄:Cr/1:0.5 and In₂O₃/ZnGa₂O₄:Cr/1:2, achieving complete degradation after 80 min under UV light irradiation. Moreover, it exhibits long afterglow luminescence that lasts for more than 72 h. Thus, the In₂O₃/ZnGa₂O₄:Cr/1:1 composite shows great potential for use in round-the-clock photocatalytic applications.