Preparation of <scp> TiO ₂ </scp> _{‐ <i>x</i>} Via Inorganic Chemical Reduction Method and its Applications in Solar‐Driven Photothermal Water Evaporation: Progress and Prospects

Global water scarcity and pollution present critical challenges for human society. Solar‐driven wastewater treatments, such as photocatalytic degradation of organic pollutants and photothermal conversion water evaporation, offer promising solutions. TiO 2 has garnered extensive attention in these fields, but its large bandgap limits light absorption, affecting its performance and broader applications in energy and environmental fields. Consequently, modifying TiO 2 to improve its photocatalytic and photothermal conversion performance has become a research hotspot. Among various modification strategies, self‐doping with Ti 3+ and oxygen vacancies can reduce the bandgap of TiO 2 , improve sunlight utilization, and increase the separation efficiency of photogenerated electron–hole pairs, thereby significantly enhancing the photocatalytic and photothermal conversion performance. This review focuses on the inorganic chemical reduction methods for preparing Ti 3+ /oxygen vacancies self‐doped TiO 2 and their current applications in solar‐driven photothermal conversion water evaporation. It highlights the challenges faced during synthesis and application while offering insights into future development prospects. This review is expected to provide a valuable reference for further research on the preparation and application of Ti 3+ /oxygen vacancies self‐doped TiO 2 .