Advances in heterogeneous photocatalytic selective oxidation of toluene

Volatile organic compounds (VOCs), such as toluene, pose significant environmental and health risks, underscoring the need for efficient, sustainable abatement technologies. While complete oxidation mineralizes toluene into CO₂ and H₂O, it lacks economic value and causes greenhouse gas emissions. In contrast, photocatalytic selective oxidation offers a promising alternative approach by converting toluene into high-value chemicals, such as benzaldehyde, under mild conditions, aligning with circular economy principles. This review comprehensively summarizes recent advances in photocatalyst design and modification strategies for the selective oxidation of toluene, including surface/interface regulation, heterojunction construction, elemental doping, and development of novel catalytic systems. Key challenges such as high C(sp³)-H bond activation energy, inefficient charge separation, and over-oxidation are discussed. Future perspectives highlight the importance of more in situ mechanistic studies, rational catalyst design, reactor scalability, and system optimization for practical applications. Through interdisciplinary efforts, the photocatalytic selective oxidation of toluene is poised to become a green, economically viable route for organic synthesis.