Surface catalytic effect of Ag nanoparticles and influence of dissolved oxygen on photocatalytic reduction of nitrate.

Photocatalytic reduction of nitrate is a promising green strategy to remove nitrogen pollutants from water bodies. However, it is a considerable challenge to directly reduce nitrate using photogenerated electrons. In this work, a g-CN/Ag-nanoparticle composite demonstrating high catalytic activity toward nitrate is constructed using an photodeposition method. Based on photoelectrochemical, ion chromatography and nuclear magnetic resonance characterization, Ag nanoparticles were found to exhibit strong surface catalytic activity for reducing NO to NO , while g-CN/Au-nanoparticles exhibited no photocatalytic reduction activity toward NO . Additionally, the effects of dissolved oxygen on the photocatalysis system of nitrate reduction are analyzed for the first time.