Effects of manganese-doping on the enhanced solar photocatalytic properties of AgBr catalyst: Mechanism and DFT modeling

Abstract

Manganese ion doping engineering, is promising in the field of photocatalysis, but its effect on simple structure semiconductor is not clear. In this work, high-efficiency manganese doped AgBr photocatalysts were manufactured via an ice bath deposition process and were systematically characterized. Under simulated sunlight irradiation, Mn2+ doped AgBr possessed good degradation activity to rhodamine B (RhB) and Ciprofloxacin (CIP). Notably, the optimal sample AM-2 (the mole ratio of Mn element in the whole sample is 0.014 %) can degrade RhB at a reaction rate constant of 0.10334 min-1, which was 7.72 times that of pure AgBr. In light of density functional theory (DFT), the improvement of photocatalytic performance was due to the incorporation of Mn ions that induced lattice strain, affected the charge distribution, and generated an intermediate Mn 3d-Br 2p two-dimensional energy level in the AgBr band gap. Photoelectrochemical experiments verified that Mn2+ doping promoted the separation and transfer of photogenerated carriers and enhanced light absorption. In addition, the practical application ability of photocatalyst was investigated, and a reliable photocatalytic mechanism was proposed. This study may provide enlightening significance for the general application of doping engineering.