Near-Infrared Light Responsive TiO2 for Efficient Solar Energy Utilization

TiO2, as a benchmark in the field of ultraviolet photocatalysis, is one of the most widely used semiconductor photocatalysts. However, its inherent drawbacks, including wide bandgap and fast recombination of charge carriers, lead to the underutilization of solar light. Increasing the overall solar spectrum utilization of TiO2, especially in the near-infrared region (NIR, approximate to 52%), is the key to efficient solar energy conversion. In this review, the strategies to enhance NIR light capture of TiO2-based photocatalysts, including hybridization with narrow optical gap semiconductors, bandgap engineering, upconversion materials, plasmonic materials, and photosensitizers, are elaborated. The basic mechanisms for NIR light conversion employed by TiO2 and the preparation methods of photoactive materials are summarized. Furthermore, their applications in photocatalytic pollutants purification, hydrogen and oxygen evolution, multifunctional smart windows, nitrogen photofixation, as well as carbon dioxide photoreduction and photocatalytic disinfection are discussed. Finally, this review presents the limitations and perspectives for the future development of efficient NIR solar photon conversion of TiO2-based materials.

Automated summary

TiO2, a widely used semiconductor photocatalyst in the field of ultraviolet photocatalysis, faces challenges like wide bandgap and fast recombination of charge carriers, affecting its solar light utilization. Enhancing the overall solar spectrum utilization of TiO2, especially in the near-infrared region, is crucial for efficient solar energy conversion. Strategies such as hybridization with other semiconductors and bandgap engineering are discussed to improve NIR light capture of TiO2-based photocatalysts in this review, along with their applications in various fields and future development prospects.