Oxygen-Deficient TiO₂ Aerogel for Enhanced Photocatalytic Performance

Low charge-separation efficiency is a major factor limiting the photoelectric conversion performance of TiO₂. In this work, oxygen-vacancy-rich porous TiO₂ gel photocatalyst was successfully fabricated. The as-prepared material exhibits a three-dimensional interconnected hierarchical porous architecture with a specific surface area of 62.9 m² g^-1. EPR and XPS analyses confirmed the presence of Ti³⁺ defects and oxygen vacancies, which effectively increase the electron density and facilitate the separation and migration of photogenerated charge carriers. The results demonstrated excellent photocatalytic activity, with over 85% of RhB degraded within 50 min under light irradiation. In addition, its photocatalytic performance was further investigated by photocatalytic hydrogen evolution, and the hydrogen production rate reached 850.6 μmol·g^-1 h^-1. The enhanced photocatalytic performance can be mainly attributed to the synergistic effect of the hierarchical porous structure and oxygen vacancies. Specifically, the hierarchical porous structure improves mass transfer and provides abundant active sites, while oxygen vacancies modulate the electronic structure and promote charge separation, thereby significantly enhancing the catalytic activity. This work provides an effective strategy for improving the photoelectric conversion performance of TiO₂ and offers theoretical guidance as well as experimental support for the defect engineering and structural design of TiO₂-based photocatalytic materials.