Preparation of Silver Carbonate and its Application as Visible Light-driven Photocatalyst Without Sacrificial Reagent

Visible light-driven photocatalyst is the current research focus and silver oxyacid salts with p-block elements are the promising candidates. In this research, Ag2 CO3 was prepared by a facile precipitation method and used to degrade the pollutants from waters. The results revealed that the silver carbonate with monoclinic structure quickly decomposed methyl orange and rhodamine B in less than 15 min under visible light irradiation. When it was recycled six times, the degradation of methyl orange still can reach 87% after 30 min. The calculated band gap of Ag2 CO3 was 2.312 eV with Valence band edge potential of 2.685 eV and Conduction band 0.373 eV vs NHE, which endowed the excellent photo-oxidation ability of silver carbonate. Photogenerated holes and ozone anion radicals were the primary active species in the photo-oxidization degradation of dye. The generation of metallic silver resulted from photocorrosion and the consequent reduction in the ozone anion radical amount led to the performance degradation of Ag2 CO3 . The simple preparation method and high photocatalytic performance of Ag2 CO3 increases its prospect of application in future.