Construction of frustrated Lewis pairs on TiO2-x derived from perovskite for enhanced photocatalytic CO2 reduction

• FLPs are successfully constructed on anatase TiO 2-x hierarchical hollow boxes. • FLPs on TiO 2-x exhibit an outstanding ability for adsorption and activation of CO 2 . • CO 2 reduction is carried out in the absence of sacrificial agents and cocatalysts. • TiO 2-x with FLPs exhibits an excellent CO production rate (65.1 μmol g -1 h −1 ). Exploring high-efficiency photocatalysts to promote CO 2 reduction into high value-added products is of great significance. However, the weak adsorption and activation ability for CO 2 hampers the efficiency of photocatalytic CO 2 reduction. Herein, hierarchical hollow TiO 2-x boxes with frustrated Lewis pairs (FLPs) are successfully fabricated by in situ topological transformation of perovskite microcubes. The FLPs on TiO 2-x surface are constructed with the O Vs (Lewis acid sites) and its proximal surface hydroxyls (Lewis base sites). TiO 2-x hollow boxes with FLPs show an excellent CO production rate (65.1 μmol g -1 h −1 ) in pure water without any sacrificial agents or cocatalysts, which is 19.1 times and 36.6 times higher than those of TiO 2 without FLPs and commercial TiO 2 P25, respectively. This work presents a novel strategy to construct FLPs through in situ topological transformation route and also shows great promise for the future design of high-performance CO 2 reduction photocatalysts.