In-situ synthesis of heterojunction TiO2/MnO2 nanostructure with excellent performance in vacuum ultraviolet photocatalytic oxidation of toluene

A series of TiO2/MnO2 heterojunction catalysts were fabricated through an in-situ hydrothermal method, and for the first time, catalysts with this heterojunction structure were used for VUV-PCO toluene degradation. After the MnO2 coating, the TiO2/MnO2 catalysts performed excellently for both VOCs degradation and residual ozone decomposition with removal efficiency reaching 96.0% and 99.9%, respectively. The enhanced photocatalytic activity towards toluene degradation could be attributed to the heterojunction structure of TiO2/MnO2, which provides excellent contact between MnO2 and TiO2, and suppresses the recombination of photogenerated electron-hole pairs. Moreover, benefiting from the MnO2, the ozone generated in the system could be efficiently utilized and eliminated during the VUV-PCO process. The photocatalytic mechanism of TiO2/MnO2 for the toluene degradation and ozone decomposition was proposed.