Ag quantum dots modified hierarchically porous and defective TiO2 nanoparticles for improved photocatalytic CO2 reduction

Photocatalytic reduction of CO 2 into high added-value chemical products has received special attention. Herein, we designed a novel hierarchically porous and defective TiO 2 modified by Ag quantum dots via a hydrothermal process assisted with organic surfactant and subsequently in-situ photodeposition method. The obtained Ag quantum dots modified TiO 2 (Ag/TiO 2 ) shows excellent and stable photocatalytic activity in CO 2 reduction. In addition, the competing H 2 evolution can be completely suppressed. The super photocatalytic activity can be ascribed to the design of hierarchically porous, the intrinsic defects in TiO 2 , the localized surface plasmon resonance of Ag and the synergetic effect between Ag quantum dots and defective TiO 2 , which jointly improves the CO 2 adsorption performance, enhances visible light absorption capacity and accelerates the separation of photogenerated charges. This work may provide a strategy to design and synthesis defective and hierarchically porous metal oxides for photocatalytic CO 2 reduction.