Preparation And Properties Of Bismuth Based Metal Oxides

In recent years,water pollution due to industrial development has caused great impact on human health,flora and fauna and even the whole ecological environment.Many domestic and foreign scholars have conducted in-depth discussions on the factors affecting the environment,treatment methods,and treatment effects.The emerging treatment methods represented by photocatalytic technology have made a great splash in environmental treatment,and have become the focus of scholars at home and abroad with their advantages of high efficiency and low energy consumption.Photocatalysis has an important application prospect in the field of energy and environment,and has become a popular research topic.Metal oxides have become a hot spot for research because of their tunable and low cost,high structural stability,abundant resources and excellent catalytic activity.To address the drawback of low photocatalytic performance of single compounds,the photocatalytic performance can be improved by constructing semiconductor composites to accelerate the separation of carriers.On this basis,this paper adopts metal ion doping of bismuth metal oxides to prepare a new photocatalyst,so that the bismuth metal oxides have better photocatalytic performance.The specific studies are as follows.（1）Cu²⁺-doped bismuth tungstate photocatalysts were prepared by a one-step hydrothermal method,and the morphology,microstructure and properties of the prepared photocatalytic materials were analyzed by a series of characterization techniques（e.g.SEM,XRD,FT-IR,etc.）.The degradation of the prepared simulated dye wastewater was carried out under visible light irradiation conditions,and the photocatalytic performance of the prepared photocatalytic materials was initially investigated.The degradation efficiency of the Cu²⁺-doped bismuth tungstate composite nanophotocatalyst can reach 95.6%for rhodamine B（Rh B）solution and 98.3%for methyl orange（MO）solution by putting 0.05 g of Cu²⁺-doped bismuth tungstate in 50 m L of simulated dye wastewater at 10 mg/L,which is much higher than that of pure bismuth tungstate.This is due to the doping of copper to bismuth tungstate,which can effectively inhibit its photogenerated electron-hole pair contact and can expand its light absorption capacity to achieve the purpose of improving its photocatalytic the ability of dye itself to degrade.Not only that,but also reproducible experiments conducted on the composite nanophotocatalysts,after 5 cycles of degradation,it can still achieve high efficiency,indicating its high reusability and stability.In the end,,the photocatalytic mechanism of Cu@Bi₂WO₆composite nanomaterials was initially proposed.（2）Cu²⁺-doped bismuth molybdate one-step hydrothermal method is the main method for photocatalyst preparation,SEM and other detection methods to complete the analysis and characterization of the work.The prepared catalysts were subjected to degradation of simulated dye wastewater using visible light as the light source,and their photocatalytic activities were investigated.The effects of different process parameters conditions,such as the feeding ratio of Bi and Cu²⁺,the initial p H of rhodamine B solution,the catalyst dosage and the initial concentration of rhodamine B solution,the prepared catalysts were investigated,and the results showed that the Cu@Bi₂Mo O₆compared with pure Bi₂Mo O₆catalyst,composite nano-photocatalyst has better photocatalytic effect.This may be attributed to the fact that the composite structure formed by Cu doping onto Bi₂Mo O₆as a result,the holes and electron separation in photocatalyst are significantly improved compared with the past.In addition,reusability experiments were conducted on the composite nanophotocatalysts,after 5 cycles of degradation,it can still achieve high efficiency,indicating its high reusability and stability.