Zhangyang Li,Chunling Wang,Daoping He,Fangming Jin
Photocatalytic biomass valorization toward multicarbon chemicals holds promise for sustainable energy solutions. Nevertheless, this approach suffers from dual challenges: inherent instability of polyhydroxy intermediates and inefficient formic acid production under ambient conditions. Here, we demonstrated that a TiO 2-x photocatalyst with oxygen vacancies can effectively catalyze the transformation of glucose into arabinose, erythrose, and formic acid using O 2 as an oxidant in pure water under natural sunlight irradiation. The C 1 −OH group of glucose adsorbed on the oxygen vacancies of TiO 2-x undergoes photo-induced hole oxidation, leading to the formation of gluconolactone-TiO 2-x as a new motif. Subsequent cleavage of bonds by ·OOH radicals generated from oxygen reduction produces arabinose, erythrose, and formic acid. The oxygen vacancy strategy achieves a remarkable 53.9% yield for glucose oxidation, which exhibits 10.8-fold enhancement compared to that of conventional TiO 2 without oxygen vacancies, thereby opening new avenues for developing efficient photocatalytic systems for sustainable biomass valorization.
TiO 2 (B) nanosheets/GO (graphene oxide) hybrids are considered to be outstanding performance photocatalysts for high efficiency of H 2 evolution. However, they still suffer severe challenges during the synthetic processes, such as a large amount of the capping agents adhering on the surface and easy occurrence of aggregation. To figure out these obstacles, Ar plasma treatment as a modified method in this study not only enable the TiO 2 (B) nanosheets distributed uniformly on the GO sheets but also engineer defects within TiO 2 (B) nanosheets to significantly improve the photocatalytic activity for the water splitting. The hydrogen evolution rate of the TiO 2- x (B)/GO sheets is 1.4 times higher compared with that of original TiO 2 (B)/GO sheets without Ar plasma treatment. The improved photocatalytic properties were owing to the synergetic effects of oxygen vacancies and the heterojunction between GO and TiO 2 (B), which can promote the visible light utilization and accelerate separation and transportation of photogenerated electron-holes. This study can provide a facile pathway to prepare the two-dimensional hybrid photocatalysts with high photocatalytic H 2 activity.