Adsorption and photocatalytic degradation of gaseous benzene using TiO2@MIL-101(Cr) synthesized via in-situ method

The photocatalytic efficiency of titanium dioxide(TiO2) is easy to restrict by rapid recombination of carriers, narrow spectrum response range, and low specific surface area. Constructing heterojunctions has been widely acknowledged as a viable strategy to enhance the photocatalytic performance of TiO2. Here, TiO2@MIL-101(Cr) heterojunction was synthesized via the in-situ method and applied to adsorbing and photocatalytic degrading of gaseous benzene. The findings demonstrate 40TM exhibited the best adsorption(1157.03 μgC6H6/(g·h)) and photocatalytic(817.80 μgC6H6/(g·h)) performance, which were 2.05 and 5.21 times of TiO2, respectively. The enhancement of adsorption performance probably resulted from the higher specific surface area(637.33 m2/g) and the micro-mesoporous structure. The excellent photocatalytic performance might stem from the extended wavelength response range(400–700 nm) and the Z-scheme heterojunction formation. The possible mechanism is that electrons in MIL-101(Cr) and holes in TiO2 could participate in redox reactions to generate radicals, with superoxide radicals(∙O2−) and hydroxyl radicals(∙OH) being identified as the primary active species for benzene degradation. Overall, this investigation offers a valuable reference for the application of heterojunction catalysts in the field of adsorption-photocatalytic degradation of volatile organic compounds (VOCs).