The Research Of Preparation And Properties Of BiVO₄/HNTs Composite Photocatalytic Materials

It is difficult,when the period of coexistence energy crisis and serious environmental pollution,how to use the less energy to deal with pollution.Bismuth vanadate is a semiconductor that could response the visible light.Since it proposed,haven attracting a lot of scholar.But the problem of bismuth vanadate that have to solve,it is too small to settle down and resuse.Now,the most effective method is attach the catalyst to the mineral materials.The halloysite been wideiy used because of it cheap price and good excellent performance.But the halloysite is associated associated mine,so it must been purified.The halloysite is natural mineral with nanotubular structure.It is treated as the succedaneum of CNT,because of the special shape and the cheap price.Besides HNTs has lots of active factors and high specific surface area.So HNTs has the strong adsorption performance and high loading capacity.So the HNTs has the big the application of space because of those advantages.In this article,first of all HNTs has been purified,then utilized the purified HNTs as the carrier to prepare the BiVO₄/HNTs,finally the optimization scheme has been trying.Though some detection means like whiteness,SEM,XRD,BET to verify the HNTs.The results indicate,the purity of HNTs has been increased.The whiteness of HNTs increased from 47.2 to 70.3 after acid leaching at concentration acid of 30%,the temperature of 70 ℃ and time of 120 min.Moreover,the specific surface area of halloysite increased from 47.37m2/g to 127.40m2/g.The content of Fe2O3 decreased from 2.56% to 0.25%.In this paper,two different method has been tried.From the results,the Gel-Sol has some advantages low temperature of calcination and high crystallinity.The degradation rate is 97% when the concentration of MB is 25mg/L.The precipitation method could get the higher the catalytic efficiency of BiVO₄/HNTs.The degradation rate is 100% when the concentration of MB is 25mg/L.In addition,the paper ues zhe g-C₃N₄ composite and assist reaction to improve the effective of catalyst.Then added the g-C₃N₄ and capturing agent to composite BiVO₄/HNTs to increasing the photocatalytic efficiency.The results indicate,when the 60% quantity of g-C₃N₄ composited with BiVO₄/HNTs has the most efficient.The degradation rate increased from 42.8% to 51.3%,as the same condition.When the electron capture agent was joined,the degradation rate increased from 44% to 81.4%,as the same condition,and the hole trapping agent increased from 44% to 82.3%.So both the semiconductor composite and the capturing agent joined could increase the degradation rate of photocatalytic.