Constructing Oxygen Vacancies on Bi2MoO6 Nanosheets by Aqueous Ammonia Etching with Enhanced Photocatalytic NO Oxidation Performance

Photocatalytic technology is deemed as an ideal strategy to deal with nitrogen oxides. Constructing oxygen vacancies (OVs) on semiconductors can greatly promote photogenerated charge separation efficiency, molecular activation, and photocatalytic activity. However, a novel method for OVs introduction under moderate conditions is still lacking. In the present work, a {001} facet exposed Bi2MoO6 (BMO) nanosheet is treated in aqueous ammonia under mild conditions. In this procedure, OVs are successfully introduced into BMO via etching of the {MoO4}2– layer by aqueous ammonia, and a OVs-rich BMO-OH catalyst is prepared. Photocatalytic performance tests convey that a NO removal ratio of 47% is obtained on the BMO-OH catalyst, which is about 2.2 times higher than that of pristine BMO material. The enhanced photoactivity is attributed to high reactant adsorption and ROS generation properties of BMO-OH caused by the introduced OVs. These findings provide new insights into OVs construction and photocatalytic technology.