Boosting Photocatalytic Conversion of Glucose by Constructing Oxygen Vacancies in TiO2-x

Abstract

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 O₂ as an oxidant in pure water under natural sunlight irradiation. The C₁−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 TiO₂ without oxygen vacancies, thereby opening new avenues for developing efficient photocatalytic systems for sustainable biomass valorization.