Photo-Fenton synergistic degradation of carbamazepine and Cr (VI) over ZnIn2S4/Fe-POMs with inner-generate H2O2 and wide pH response

The photo-Fenton system degrades pollutants, which can not only take the advantages of photocatalysis and Fenton reaction, but also avoid the drawbacks of each. However, removing pollutants without the addition of hydrogen peroxide (H2O2) in photo-Fenton systems is still a challenge. Therefore, it is an outstanding strategy that inner-generate H2O2 can provide more hydroxyl radicals to enhance the degradation of pollutants. This study reports a ZnIn2S4/Fe-POMs photo-Fenton system capable of degrading environmental pollutants due to the reaction between inner-generate H2O2 (0.0248 mM in 15 min) and the stable circulation of Fe3+/Fe2+. As a result, the photodegradation efficiency of carbamazepine by ZnIn2S4/Fe-POMs can reach 93.92% within 60 min simulated solar irradiation even under neutral conditions. In addition, ZnIn2S4/Fe-POMs can remove Cr (VI) completely within 10 min under visible light irradiation. This work not only experimentally verifies the inner-generate H2O2 can accelerate the Fe3+/Fe2+ conversion, but also broadens the initial pH range (pH=3-9) for constructing efficient photo-Fenton systems.