Titanium dioxide (TiO 2 ) is a widely studied photocatalyst due to its exceptional chemical stability, low cost, and non-toxicity, making it a promising material for environmental and energy applications. However, its wide bandgap and limited visible light absorption necessitate advanced synthesis and modification strategies to enhance its photocatalytic performance. This review provides a comprehensive analysis of TiO 2 -based photocatalysts, focusing on innovative synthesis approaches and their impact on photocatalytic applications. Various synthesis techniques, including sol–gel, hydrothermal, flame spray pyrolysis, electrochemical, and green synthesis, are explored, highlighting their influence on particle size, morphology, crystallinity, and efficiency. Additionally, the review discusses modification strategies such as metal and non-metal doping, heterojunction formation, and surface functionalization to improve visible-light activity and charge separation. Surface functionalization can enhance dispersion, adsorption, or charge transfer depending on the functional groups introduced. The photocatalytic applications of TiO 2 in environmental remediation, energy conversion, air purification, and self-cleaning surfaces are critically examined, with an emphasis on recent advancements in green synthesis and novel TiO 2 composites. The review also addresses challenges related to scalability, cost effectiveness, and long-term stability, underscoring the need for continued innovation in TiO 2 -based photocatalysis to drive sustainable environmental and energy solutions.
Getaneh et al. (2026) studied this question.