Preparation And Photocatalytic Properties Of BiOi

TiO₂ has been extensively investigated for solar energy conversion and the deco mposition of organic pollutants owing to its stability,low cost,non toxicity and high p hotocatalytic activity.However,the large band gap made TiO₂?3.0eV for rutile TiO₂and 3.2eV for anatase TiO₂?only absorb UV light?3–5%of solar light?,can not absorb visible light?45%of solar energy?for such functionalities.The utilization rate of solar light is very low.In addition,the light produced by the light is easy to be composite,which leads to the decrease of the quantum efficiency of TiO₂,which makes the visible light activity decreased.In order to develope visible-light-driven photocatalysts,research innumerous laboratories has focused on non-TiO₂catalysts?Following the discovery of bismuth-based ternary metaloxide photocatalysts BiOI have lately been found to exhibit remarkable photocatalytic activity under UV andvisible light irradiation.BiOI is an important IV–V–VI ternary semiconductor compound because of their optical properties.In the past years,BiOX havebeen reported as efficient photocatalysts to decompose pollutantsinto non-toxic molecules for environmental remediation.And more and more researchers have been studying the photocatalytic performance of BiOI under sunlight irradiation.BiOI was the current research hotspot.But currently most of the BiOI synthesis requires expensive chemicals,high temperature and high pressure conditions.Patchy structure of the synthetic samples were irregular or larger size,limiting photocatalytic activity of BiOI.In this paper,Bismuth nitrate pentahydrate?Bi?NO₃?₃·5H₂O?and potassium iodide?KI?were chosen as the Bi and I sources,respectively.BiOI were preparedviaadding ethylenediamine tetraacetic acid disodium,sodium dodecyl sulfate and sodium dihydrogen phosphate.The samples were characterized by X-ray diffraction,infrared spectroscopy,scanning electron microscopy,transmission electron microscopy,UV-visible diffuse reflectance spectroscopy,X-ray photoelectron spectroscopy and X-ray absorption near edge structure?XANES?.BiOI with adding ethylenediamine tetraacetic acid disodium,sodium dodecyl sulfate and sodium dihydrogen phosphate studied about its crystal phase composition,morphology,optical properties and its microstructure.Furthermore,the visible light catalytic activity was tested by using methyl orange and rhodamine B as simulate pollutants and xenon lamp with power of 300W and a wavelength of 420⁸00nmas a light source.The results as follows:1?Added samples of ethylene diamine tetraacetic acid disodium,XRD analysis shows that the sample for pure BiOI,With the increasing amount of samples,the sample gradually changed from flake to flower.When the addition is 10%,flower-like structures are destroyed,becoming irregular microspheres;BET analysis shows that,with increased of added,specific surface area first increased and then decreased.In addition to the amount of 8%,the maximum of surface area is 14.512 m²g^-1;XPS and EDX showed that samples only have Bi,O,and I.XPS shows that samples have no Bi₂O₃ and metal Bi,which consistented with XRD results;Photocatalytic performance indicates that the sample of adding amount of 10%shows the best photocatalytic activity,and in the light for 240mindegradation rate of methyl orange up to 79.73%.The sample of adding amount of 8%shows the best photocatalytic activity,and in the light for40mindegradation rate of rhodamine B up to 95.63%.2?Added samples of sodium lauryl sulfate,XRD analysis shows that the sample for pure BiOI;with the addition of increasing amounts,the sheet-like structure gradually becomes smaller,when added to 10%,the particle size is the smallest,which consistentedwith the XRD results.BET analysis shows that,with the increase of adding,specific surface area first increased and then decreased.In addition to the amount of 10%,The maximum of surface area is 23.844m²g^-1;photocatalysis research has shown that,with the increasing amount of samples,the degradation rate first increased and then decreased,when the addition is 10%,the degradation of methyl orange is the best,the degradation rate is 94.28%in the 120min.3?Added sodium dihydrogen phosphate,XRD analysis shows that the sample for pure BiOI,with the increasing amount of samples,the sample gradually changed from flake to flower.When the addition is 6%,flower-like structures are destroyed,be coming irregular microspheres;BET analysis shows that,with the increase of added,specific surface area first increased and then decreased.When the addition is 4%,surface area maximum is 14.493 m²g^-1;XPS and EDX showed that samples only have Bi,O,I and P,XPS showed that samples have no Bi₂O₃ and metal Bi,P may be attached to the surface of BiOI;Photocatalytic performance shows that the 4%P–BiOI showed the best photocatalytic activity,and in the light for180mindegradation rate of methyl orange up to 82.81%,and in the light for 40 mindegradation rate of rhodamine B up to 95.53%.Photocatalytic mechanism shows that·O^2-generation and h⁺dyedegra dation has a significant role,the role of·O^2-is greater than h⁺.