Synergistic reduction of U(VI) and selective oxidation of benzyl alcohol to prepare benzaldehyde via WOx/g-C3N4

In the photoreduction of U(VI), protective gases and additional sacrificial agents are still the major obstacles. Herein, we developed an oxygen-deficient WO x /g-C 3 N 4 catalyst for the simultaneous reduction of U(VI) and preparation of benzaldehyde by selective oxidation of benzyl alcohol without protective gases and sacrificial agents. The removal of U(VI) by WO x /g-C 3 N 4 could reach 98.5% and the conversion of benzyl alcohol was nearly 32% with a selectivity close to 100%. Compared with single g-C 3 N 4 and defect-free WO 3 , the photoreduction activity of WO x /g-C 3 N 4 was 10.4 and 7 times higher, respectively. Besides, the role of oxygen and oxygen defects was explored. Owing to oxygen defects in the catalyst, oxygen was adsorbed on the oxidation end (WO x ) of the catalyst and activated without entering the reduction end to interfere with the photoreduction of U(VI), while favoring the generation of •O 2 - to improve the selectivity of benzaldehyde. Finally, a new mechanism was proposed.