Se–Se bonds induced highly metallic 1T’ MoSe2.3 nanosheets cocatalysts towards boosted H2O2 photosynthesis over NH2-MIL-125 derived TiO2 nanotablets

Loading non-noble metal cocatalysts is a promising means to inhibit the photogenerated charge recombination and provide more active centers for surface photocatalytic reactions, especially for hydrogen peroxide (H2O2) generation. The H2O2 photosynthesize activity has shown to be seriously limited by secondary decomposition of synthesized H2O2, owing to the presence of metal-based active centers. Herein, highly metallic MoSe2.3 nanosheet with dominated 1T and 1T' phase were in-situ loaded onto the NH2-MIL-125(Ti) derived TiO2 nanotablets via a one-step hydrothermal method to form a TiO2/MoSe2.3 composite for enhancing photocatalytic H2O2 production activity. The abundant edge Se–Se bonds, along with the high content of 1T and 1T' phase endowed MoSe2.3 nanosheets with highly metallic property to function as an efficient cocatalyst to accelerate the carrier separation. Besides that, Se–Se bonds could offer more active centers for O2 adsorption for boosting the generation of H2O2. As a result, the optimal TiO2/MoSe2.3 composite photocatalyst (TM-5) displayed a much enhanced H2O2 production performance of 891 µmol L–1 h−1 in isopropanol solution (IPA, 10 vol%) under monochrome LED-(365 nm) light irradiation, 2.3 times higher than pure NH2-MIL-125 derived TiO2 nanotablets. This work would provide a feasible method in non-metal cocatalyst design for H2O2 photosynthesize.