Towards high-efficiency photocatalytic TiO₂ nanosheets: mechanisms, modifications, and breakthroughs

As a green and sustainable technology, solar driven photocatalytic processes for renewable energy generation have garnered increasing attention to address the imminent energy and environmental crises. Consequently, extensive research has been conducted on photochemical principles, particularly the photocatalysis of titanium dioxide (TiO₂), through various surface science methodologies. Among them, two-dimensional (2D) TiO₂ nanosheets characterized by their large specific surface area, unique structural flexibility, and tunable electronic properties compared to bulk counterparts have demonstrated significant potential for achieving high-efficiency photocatalytic performance. However, a comprehensive summary elucidating the fundamental photocatalytic mechanisms and applications of TiO₂ nanosheets remains lacking. This perspective provides the first systematic overview of phase structures, electronic configurations, photocatalytic mechanisms, performance enhancement strategies, and applications across diverse TiO₂ nanosheet variants. Furthermore, it highlights key challenges and future directions, emphasizing the integration of advanced computational methods with experimental insights to guide the rational design of TiO₂ nanosheet based photocatalytic systems for sustainable energy conversion.