Synthesis And Visible Light Photocatalytic Performance Of Ag₂O/Zinc Pyrovanadate Composite Catalyst

With the rapid development of the social economy,the ensuing environmental problems have become serious increasingly,and the photocatalytic technology is highly effective and environmentally friendly for water pollution control.It has attracted the attention of researchers gradually.Zinc pyrovanadate has a good development prospect in the field of photocatalysis due to its special spatial structure and suitable energy level.However,due to its narrow light response range,it has low utilization of visible light and low photocatalytic activity.This paper intends to use a narrow bandgap material to reduce its forbidden band gap.Therefore,the narrow-bandgap Ag2O is compounded with zinc pyrovanadate by hydrothermal and precipitation two-step method,and characterized by XRD,SEM,UV vis DRS BET,etc..Using methylene blue as a probe contaminant,the photocatalytic activity of the composite catalyst prepared under different conditions was investigated,and the best preparation conditions were selected.Based on the composite catalyst prepared under the optimal conditions,the factors affecting the degradation of methylene blue and eosin B by the composite catalyst were investigated,and the reuse performance of the composite catalyst was explored.The conclusions of this paper are as follows:(1)When the photocatalyst prepared at the current liquid-repellent pH of 10,the composite ratio of 3:10,the hydrothermal time of 10h,and the hydrothermal temperature of 120?,it has the best photocatalytic activity.After reacting for 60 min under visible light,the decolorization of methylene blue reached 97.9%,which was significantly higher than 17.1%of zinc pyrovanadate alone or 18.7%of Ag2O.(2)The degradation of methylene blue and eosin B was carried out by the composite catalyst prepared under the optimal conditions.The results showed that the adsorption of methylene blue and eosin B by the composite catalyst was small;Under the conditions that the initial concentration of the solution was 20 mg/L,and the pH of the solution was acidic,the decolorization rate of methylene blue and eosin B can reach more than 99%;NaCl has a certain inhibitory effect on the degradation of methylene blue and eosin B by the composite catalyst;the repeated use experiments of the composite catalyst showed that the composite catalyst has good stability.(3)The photocatalytic degradation of methylene blue and eosin B by the composite catalyst accords with the first-order kinetic model.As the initial concentration of the solution increases,the apparent reaction rate constant K decreases continuously.