Controllable preparation of hierarchical MnCo bimetallic photocatalyst and the effect of atomic ratio on its photocatalytic activity

In recent years, bimetal has become an important branch of catalysis because of its unique interatomic synergistic activity. In this study, the effects of different preparation temperatures and atomic ratios on the activities of manganese-cobalt bimetallic photocatalysts and their catalytic mechanisms were investigated. Specifically, a series of hierarchical MnCo bimetals were prepared at 180 ∼ 200 ℃ with Mn:Co ratios of 2:1, 1:1 and 1:2 by a simple “hydrothermal/reduction” method. The results of the photoelectrochemical tests and density functional theory (DFT) show that the light absorption range, photocurrent, photovoltage and energy density of the materials are greatly affected by the preparation temperature and atomic ratio. The degradation rate of the representative MnCo2-190 bimetal to norfloxacin (NOR) reached 98.91% within 65 min. In addition to the characteristics of CoMn2 and MnCo, MnCo2 excites local surface plasmon resonance (LSPR) under light irradiation, resulting in strongest catalytic activity through Landau damping effect.