Enhanced photocatalytic degradation performance of In2O3/g-C3N4 composites by coupling with H2O2.

ABSTRACT

Environmental pollution by organic pollutants poses a great threat to the ecosystem and human development. Solar-powered catalytic oxidation technology can solve the existing energy and pollution crisis. Hence, in this work, cubic nano-In2O3 modified g-C3N4 composite was synthesized by in situ calcination, then it was coupled with hydrogen peroxide for the degradation of antibiotic under visible light. The results of SEM and XPS showed that In2O3 and g-C3N4 were closely combined. The catalytic oxidation efficiency of the antibiotic doxycycline was greatly improved when the as-prepared compound was coupled with hydrogen peroxide, and 88.2% of doxycycline was degraded within 80 min. By designing the active species inhibition test, it was found that a large number of hydroxyl radicals were generated in the system after adding hydrogen peroxide, which accelerated the degradation of the target. Hydrogen peroxide not only acts as a source of hydroxyl radical, but also as an active electron acceptor, which promotes the separation of photogenerated electron-hole pairs in the composite photocatalyst. Therefore, the double oxidation system formed by In2O3/g-C3N4 coupled with hydrogen peroxide can degrade the target at a higher rate. This work provided a research basis for the synthesis of In2O3 with regular morphology and simplified synthesis of In2O3/g-C3N4, and explored the practicability of the coupling method of double advanced oxidation for pollutant degradation.