Construction of TiO 2 /SrTiO 3 Heterojunction Derived from Monolayer Ti 3 C 2 MXene for Efficient Photocatalytic Overall Water Splitting.

Construction of heterojunction at the atomic scale to ensure efficient charge separation for improvement of photocatalytic water splitting is challenging. Herein, a facile hydrothermal method has been applied for the in situ fabrication of TiO /SrTiO heterojunction, using the monolayer Ti C MXene as the template and reactant. It is found that the sample with the hydrothermal reaction time of 60 min exhibits the highest H evolution rate with the sacrificial reagent, due to the efficient charge separation of TiO /SrTiO heterojunction as Ti C derivative. In addition, the sample shows the best overall water splitting performance at a hydrothermal reaction time of 120 min, where TiO is nearly converted to SrTiO , due to the fast kinetic process and low structural defects of SrTiO . This work not only provides a simple strategy for the fabrication of heterojunction photocatalysts but also demonstrates the difference in optimization of half-reaction and overall water splitting reaction.