Preparation And Photocatalytic Properties Of Bi₂MoO₆ Nanomaterials

In recent years,with the progress and development of social industry,the problem of energy storage and environmental pollution has become a hot topic in the world.Semiconductor photocatalyst is a promising and widely used material,which can use ultraviolet light in the sun to convert ultraviolet light energy into chemical energy to decompose water into hydrogen and organic pollutants into harmless water and carbon dioxide.At present,photocatalytic materials are mainly used in three aspects:water light is decomposed into hydrogen and oxygen to solve energy problems;Reducing carbon dioxide to methane organic fuel to solve greenhouse effect;And the degradation of organic pollutants into pollution-free water and carbon dioxide to solve the problem of environmental pollution.Therefore,photocatalyst is a promising functional material.At present,however,most photocatalysts only use ultraviolet light,which accounts for only 5%of the sunlight,so the photocatalytic efficiency is very low,which is far from enough to meet the industrial demand.Therefore,it is necessary to find new and efficient photocatalysts.Semiconductor photocatalysis,with its advantages of low cost,simplicity and efficiency,is an effective,green and potential method to degrade many toxic organic pollutants in water system.The industrial application of this technology relies on the development of efficient and stable visible light driven photocatalysts.The research of photocatalyst has made great progress,and the photocatalyst has a broad application prospect in the use of sunlight to degrade organic pollutants in industrial wastewater.Many bandgap photocatalysts limit their availability to irradiated light.Therefore,it is necessary to develop semiconductor photocatalysts driven by visible light to effectively utilize the solar spectrum.At present,according to the research and progress of bismuth molybdate photocatalytic very substantial,the preparation of nanoscale Bi₂MoO₆,photocatalytic mechanism and influence factors were summarized,points out that the system of light type and light intensity,reaction temperature and the p H of the system and so on are the main factors influencing the Bi₂MoO₆ catalytic efficiency and speed,on the basis of summed up the method to improve nanometer Bi₂MoO₆ photocatalytic activity,and surface modification of doped semiconductor material two kinds of main mode has carried on the induction,this paper introduces the Bi₂MoO₆ as photocatalyst in application in the field of environment and the service life,The development trend of Bi₂MoO₆ as photocatalyst was proposed.In this paper,Bi₂MoO₆ was used as the research object to change the photocatalytic properties of bismuth molybdate under the same conditions by different surfactants,and the photocatalytic properties of bismuth molybdate were improved by different metal doping.The following research results are mainly obtained:(1)Bi₂MoO₆was prepared by solvent heating method,and the morphology of bismuth molybdate was changed by adding different surfactants to produce different photocatalytic effect of bismuth molybdate.The effect of different surfactant types on the morphology and structure of Bi₂MoO₆ was studied.The product was characterized by XRD,SEM and FTIR.The results showed that the thickness of the prepared nano-sheet was only 10?20 nm when cetyltrimethylammonium bromide(CTAB)was used as the surfactant in hydrother-mal synthesis.This bismuth molybdate nanometer sheet has better photocatalytic activity than ordinary bismuth molybdate nanometer powder.The degradation rate of the target pollutant rhodamine(Rh B)can reach 95%after 120 min of visible light irradiation,and the visible light catalytic efficiency is improved by 2?4 times.The morphology and photocatal-ytic effect of bismuth molybdate were also influenced by different surfactants.(2)the best photocatalytic effect of Co-Bi₂MoO₆ doped with bismuth molybdate was prepared by solvent thermal method.As the doping amount of Co increased from 0 to0.4%,a flower microsphere composed of Bi₂MoO₆ nanometer plate of orthogonal crystal system was presented.Among these co-doped samples,0.1%Co-Bi₂MoO₆ samples showed that under the irradiation of visible light within 120 min,the degradation efficiency of Rh B was 99.7%,higher than that of pure Bi₂MoO₆ and Co doped Bi₂MoO₆ microspheres.The0.1%Co-Bi₂MoO₆ microspheres with high photocatalytic performance are promising photocatalytic materials.(3)Bi₂MoO₆ was prepared from bismuth molybdate by solvent heating method.Then Bi₂MoO₆ doped with Ni²⁺and Ti⁴⁺ions was prepared by initial wet impregnation and calcination.The effects of co-doping of Ni²⁺and Ti⁴⁺with different concentrations on Bi₂MoO₆ crystal,morphology and optical properties were studied.Under visible light irradiation,the effect of Ni²⁺and Ti⁴⁺surface co-doping on Bi₂MoO₆ photocatalytic activity was proved by degradation of Rh B,and the results showed that Ni²⁺and Ti⁴⁺co-doping can significantly improve the visible light absorption of Bi₂MoO₆ and promote the separation of photogenerated charge carriers.Ni/Ti/Bi₂MoO₆-3 showed the best photocatalytic activity and stability in degradation of rhodamine(Rh B)by co-doping the best Ni²⁺and Ti⁴⁺.