Synergistic Effect of Y Doping and Reduction of TiO2 on the Improvement of Photocatalytic Performance

Pure TiO2 and 3% Y-doped TiO2 (3% Y-TiO2) were prepared by a one-step hydrothermal method. Reduced TiO2 (TiO2-H-2) and 3% Y-TiO2 (3% Y-TiO2-H-2) were obtained through the thermal conversion treatment of Ar-H-2 atmosphere at 500 & DEG;C for 3 h. By systematically comparing the crystalline phase, structure, morphological features, and photocatalytic properties of 3% Y-TiO2-H-2 with pure TiO2, 3% Y-TiO2, and TiO2-H-2, the synergistic effect of Y doping and reduction of TiO2 was obtained. All samples show the single anatase phase, and no diffraction peak shift is observed. Compared with single-doped TiO2 and single-reduced TiO2, 3% Y-TiO2-H-2 exhibits the best photocatalytic performance for the degradation of RhB, which can be totally degraded in 20 min. The improvement of photocatalytic performance was attributed to the synergistic effect of Y doping and reduction treatment. Y doping broadened the range of light absorption and reduced the charge recombination rates, and the reduction treatment caused TiO2 to be enveloped by disordered shells. The remarkable feature of reduced TiO2 by H-2 is its disordered shell filled with a limited amount of oxygen vacancies (O(V)s) or Ti3+, which significantly reduces the E-g of TiO2 and remarkably increases the absorption of visible light. The synergistic effect of Y doping, Ti3+ species, and O(V)s play an important role in the improvement of photocatalytic performances. The discovery of this work provides a new perspective for the improvement of other photocatalysts by combining doping and reduction to modify traditional photocatalytic materials and further improve their performance.

Automated summary

Pure TiO2 and 3% Y-doped TiO2 were prepared through hydrothermal method, and then reduced TiO2 and 3% Y-TiO2 were obtained by thermal conversion treatment. The synergistic effect of Y doping and TiO2 reduction was observed, leading to enhanced photocatalytic performance. The improvement was attributed to expanded light absorption range and reduced charge recombination rates caused by Y doping, as well as the disordered shells filled with oxygen vacancies and Ti3+ resulting from reduction treatment. This discovery provides a new perspective for modifying photocatalytic materials and improving their performance.