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 syn-thesis 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 lmol center dot g-1 center dot 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 syner-gistically 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.(c) 2022 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan.