Recent advances on TiO2-based photocatalytic CO2 reduction

The sufficient supply of energy remains one of the most important challenges for a sustainable development of our society. In this respect, capturing sunlight energy by photocatalytic reduction of the greenhouse gas CO2 is interesting. In a more general way, the smart use of CO2 as C1-feedstock and its conversion to valuable carbon-based materials and energy sources can be the basis to establish a closed-CO2 cycle. This review summarizes recent advances in photocatalytic utilization of CO2 catalyzed by most prominent TiO2 based systems. The influences of different structures (i.e. crystal phase, morphology, vacancies, and defects), co-catalysts, and reaction conditions onto the catalyst performance are specifically highlighted. Furthermore, the reader attention is drawn to the oxidation counter reaction, which has been often neglected in the past.