TiO2-based catalysts for photothermal catalysis: Mechanisms, materials and applications

Photothermal catalysis (or thermal-photo catalysis) has emerged as a rapidly growing research topic. In contrast to the conventional photocatalytic process at room temperature, thermal energy is coupled into photocatalysis to assist photocatalytic reactions, which can significantly improve the catalytic activity and modulate the catalytic reaction path and selectivity. This review specifically summarizes the recent developments on TiO 2 -based materials employed in photothermal catalysis. Firstly, the mechanisms and physics accounting for the thermal energy-improved photocatalysis are summarized from different aspects, including light absorption, charge separation and migration, reaction intermediates, thermal kinetics and surface reaction. Then, the characteristics, principles, distinctions and applications of two modes of thermal energy introduction, external heating (bulk heating) or self-heating (local heating), are illustrated, respectively. From the development of materials aspects, the recent progress on TiO 2 -based catalysts investigated in photothermal catalysis is categorized and discussed. Some representative examples in the applications of hydrogen production, carbon dioxide reduction, pollutants degradation, chemical synthesis and conversion and biomass utilization are shown to illustrate the broad applicability of photothermal catalysis. Lastly, we present the challenges and perspectives in this field, as a guide for future development in photothermal catalysis. • The influences of thermal energy on heterogeneous photocatalytic processes are analyzed. • Different heat sources and mechanisms in photothermal catalysis are introduced. • Strategies for modifying TiO 2 -based photothermal catalysts are summarized. • Applications of TiO 2 -based photothermal catalysts are reviewed.