TiO2-based photocatalysts for CO2 reduction and solar fuel generation

Solar-driven CO2 reduction is an efficient way to convert sustainable solar energy and massive CO2 to renewable solar fuels, such as CH4, HCOOH, HCHO, and CH3OH, etc. Up to now, significant research efforts have been devoted to exploring the reaction path and developing the photocatalysts. In heterogeneous photocatalysis, among the semiconductor-based photocatalysts, titania (TiO2), as an inexpensive and practically sustainable metal oxides, remains the most extensively studied photocatalyst over the past decades. In this review, we summarize the most recent advances in the solar-driven CO2 reduction using TiO2-based photocatalysts, which include the fabrication of heterojunction, surface functional modification, band structure engineering, and morphology design, aiming to improve the CO2 conversion efficiency and selectivity to the desired product. Additionally, photoelectrochemical and photothermal approaches are introduced and the fundamental principles to activate and enhance the performance of TiO2 for the specific reaction are discussed. The exploration of the solar-driven approaches and discussion on the underlying mechanism allow the comprehensive understanding of CO2 photoreduction, that can lead to a rational design and synthesis of TiO2-based photocatalysts.