Improved Photocatalytic Activity of Porous In2O3 by co-Modifying Nanosized CuO and Ag with Synergistic Effects

Charge separation and oxygen activation are two crucial factors in the photocatalytic oxidation of pollutants, and it is meaningful to simultaneously enhance charge separation and promote O2 activation. Herein, it is demonstrated that the photocatalytic activity of porous In2O3 is greatly improved after co-modifying nanosized CuO and Ag for oxidizing 2,4-dichlorophenol(2,4-DCP) and CO compared with that of individual In2O3. Based on the surface photovoltage spectroscopy, O2 temperature-programmed desorption, electron paramagnetic resonance spectroscopy and electrochemical results, the improved photoactivity is mainly attributed to the synergistic effects of enhancing photogenerated charge separation and promoting oxygen activation by respectively coupled nanosized CuO and Ag. It is confirmed that the produced ·O2− radicals are dominant to induce the photocatalytic oxidation of 2,4-DCP. This work offers an effective way to develop high-activity In2O3-based nanophotocatalysts for oxidizing pollutants.