Facile microwave-assisted synthesis of In2O3 nanocubes and their application in photocatalytic degradation of tetracycline

Novel In2O3 nanocube photocatalysts were successfully prepared by a facile microwave-assisted synthesis method. The obtained products are nano-sized with square corners and high crystallinity. The In2O3 nanocubes possessed high efficiency of electron-hole separation, resulting in high photocatalytic activities for the degradation of tetracycline under both visible light (λ > 420 nm) and full-range light irradiation (360-760 nm), the ratios of which are 39.3% and 61.0%, respectively. Moreover, the calculated positions of the CB and VB under our experimental conditions at the point of zero for In2O3 nanocubes are -0.60 V and +2.17 V, respectively. Note that the redox potentials of [O2/·O2 -] and [·OH/OH-] are -0.33 V and +2.38 V, respectively, which means that the irradiated In2O3 nanocubes can reduce O2 into ·O2 - without oxidizing OH- into ·OH. It can be concluded that ·O2 - and h+ are the main active species of In2O3 in aqueous solution under visible light irradiation and full-range light irradiation.