Enhanced Photocatalytic Production of H2O2through Regulation of Spatial Charge Transfer and Light Absorption over a MnIn2S4/WO3 (Yb, Tm) Z-Scheme System

The photocatalytic production of hydrogen peroxide (H2O2)from H2O and O2is a promising approach, owing to its advantage ofutilization of green solar energy without addition of organic sacrificialagents. However, the H2O2productivity is still far from satisfactory, due toinefficient sunlight absorption and the low photogenerated charge mobilityof photocatalysts. Herein, a Z-scheme photocatalytic system is constructedby combining MnIn2S4with Yb3+and Tm3+WO3(WO3(Yb, Tm))semiconductors. The Z-scheme interface heterojunction can inhibit therecombination of photogenerated carriers and retain photogeneratedelectrons and holes with high redox potentials. Particularly, the co-dopedYb3+and Tm3+can harvest near-infrared (NIR) excitation energy and thengeneratefluorescence emission with shorter wavelengths, which is beneficialto expand the optical response range of the photocatalytic system. With thesynergy of the promoted photogenerated charge separation and enhanced optical absorption, the proposed photocatalytic system ofMnIn2S4/WO3(Yb, Tm) exhibits a H2O2production rate of 1188 mu mol h-1g-1in pure water, which is 37.2 and 8.8 times that ofWO3and MnIn2S4, respectively. This work offers a new avenue for the design and improvement of photocatalytic systems for H2O2production.

Automated summary

This study successfully improves the efficiency of producing H2O2 from H2O and O2 by constructing a Z-scheme photocatalytic system. The MnIn2S4/WO3(Yb, Tm) photocatalytic system designed in this research shows high productivity of H2O2 and excellent light absorption capability.