Fabrication of Ti3C2/TiO2/SrTiO3 ternary heterojunction photocatalyst with efficient charge separation for enhanced hydrogen evolution

In this work, a ternary Ti 3 C 2 /TiO 2 /SrTiO 3 composite with heterogeneous network structure was prepared by two-step in situ hydrothermal synthesis method, which mainly involved the growth of TiO 2 nanosheets and fibrous SrTiO 3 sequentially on the Ti 3 C 2 substrate using the Ti source inherent in Ti 3 C 2 as the reaction site. The Ti 3 C 2 /TiO 2 /SrTiO 3 heterojunction exhibited enhanced photocatalytic hydrogen evolution activity. When the doping amount of SrTiO 3 was 5 wt%, the hydrogen evolution rate of 5MTS under full solar irradiation reached 14322.6 μmol·g −1 ·h −1 , which was 10.6 times the rate of the Ti 3 C 2 /TiO 2 composite without modified SrTiO 3 . Meanwhile, the 5MTS composites showed good stability in the photocatalytic hydrogen evolution cycle test. The enhanced activity and recyclability are mainly attributed to the strong light absorption ability, fast separation of photogenerated electron-hole pairs, and abundant catalytic active sites. In addition, the synthesis method utilizing an intrinsic Ti source also enhances the interfacial contact between Ti 3 C 2 , TiO 2 , and SrTiO 3 . This study provides an effective reference for the construction of perovskite-based or Ti 3 C 2 co-catalyzed heterostructures and their application for the conversion of solar power to hydrogen energy .