Oxygen-vacancy-rich Ag/Bi5O7Br nanosheets enable improved photocatalytic NO removal and oxygen evolution under visible light exposure

Photocatalytic NO removal is a green and sustainable alternative to the conventional thermocatalysis in the conversion of NO to nitrates. However, the efficiency of photocatalytic NO removal is restricted by weak NO adsorption and high charge recombination on photocatalyst. Herein, we report on one-step synthesis of Ag/Bi₅O₇Br nanosheets with rich oxygen vacancies (OVs) by a facile liquid phase reduction method. Under visible light irradiation on oxygen-vacancy-rich Ag/Bi₅O₇Br for 50 min the photocatalytic NO removal ratio is up to 64.65%, which is about 1.6 times higher than that by using pristine Bi₅O₇Br. The average oxygen production rate is 823 μmol·g^?1·h^?1, which is nearly 10 times higher than that of Bi₅O₇Br. Density functional theory (DFT) calculations reveal that OVs incorporation and plasmonic Ag can synergistically strengthen NO adsorption on Bi₅O₇Br. This work highlights the great potential of defects and plasmonic metals on synergistic enhancement in photocatalytic NO removal and oxygen evolution.