Study On Synthesis Condition Optimization And Performances Of Bismuth Molybdate

There is a large amount of organic waste water in the burgeoning industry,textile and chemical industries production.The organic waste water poses a great potential threat to people's life and health.The performance of semiconductor photocatalytic materials is the key factor to determine the photocatalytic efficiency.In view of the large band gap energy of traditional photocatalysts such as TiO₂ and has no response in visible light,which restricts their application process in industrial practice.it is necessary to improve the absorption of visible light by catalysts to increase the utilization rate of light.Bi₂MoO₆ has a narrow band gap and can absorb visible light,which greatly attracts researchers.What's more,its dielectric,ionic conductivity and catalytic properties have obvious advantages in bismuth semiconductor.At present,the main disadvantage of Bi₂MoO₆ photocatalyst is that photogenerated electrons and holes are easy to compound,resulting in low quantum yield of photocatalysis,which greatly restrains the application of Bi₂MoO₆ photocatalyst in practice.Therefore,doping modification of Bi₂MoO₆ carries out in this paper to hinder the combination of photogenerated electrons and holes,and improve the photocatalytic activity of Bi₂MoO₆.Bi₂MoO₆ was prepared by continuous optimization of preparing conditions by precipitation and hydrothermal methods,the configuration and performance were measured through XRD,SEM and other testing technologies.Rhodamine B?RhB?was taken as the target degradation compound to study the visible light catalytic activity of the products.Finally,the stability of Bi₂MoO₆ prepared by different preparation methods was explored through testing and comparison.The degradation rate of RhB with Bi₂MoO₆ catalyst prepared by precipitation method was 99%at 1 h under visible light irradiation,while the rate of RhB with Bi₂MoO₆ prepared by hydrothermal method under the same conditions was only 64%.After setting one month,the photocatalytic performance of Bi₂MoO₆ prepared by precipitation method decreased by 19%,while that of the hydrothermal method decreased by only 1%.It indicates that the aging stability of Bi₂MoO₆ prepared by hydrothermal method is significantly enhanced.Bi?NO₃?₃?5H₂O,?NH₄?₆Mo₇O₂₄?4H₂O and?NH₂?₂CS were used as bismuth source,molybdenum source and sulfur source respectively,and S doped Bi₂MoO₆ was obtained by one step hydrothermal method.The results have shown that S enters into the lattice of Bi₂MoO₆ and causes lattice expansion.1%S doped Bi₂MoO₆ has high catalytic degradation performance for rhodamine B under visible light.The degradation rate of RhB is 97%after 1 h of visible light irradiation.The high photocatalysis is attributed to that S doping improves the light absorption performance of Bi₂MoO₆,which enables the effective separation of photogenerated electron-hole pairs.The capture experiment analysis shows that the main active groups of 1%S doped Bi₂MoO₆ in the photocatalytic reaction system are the superoxide radical polymer?O₂^-and hole h⁺.Electrochemical test shows that 1%S doped Bi₂MoO₆ has good photoelectrochemical properties.