Zr掺杂Bi2O3的共沉淀法制备及光催化性能评价  

PREPARATION OF ZIRCONIUM DOPED BISMUTH BY COPRECIPITATION AND ITS PHOTOCATALYTIC PERFORMANCE EVALUATION

作　　者：马颖[1] 靳晓宁 曾胜 马亚鲁[1] Ma Ying;Jin Xiaoning;Zeng Sheng;Ma Yalu(Institute of Science,Tianjin University,Tianjin 300354,Chin)

机构地区：[1]天津大学理学院

出　　处：《太阳能学报》2018年第7期1900-1907,共8页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(50972103);教育部留学回国人员科研启动基金

摘　　要：以Bi（NO3）3·5H2O、ZrO（NO3）2·2H2O为原料,NH3·H2O为沉淀剂,采用反相滴定化学共沉淀工艺制备Zr掺杂Bi2O3基光催化材料。利用X射线衍射（XRD）、透射电子显微镜（TEM）、紫外-可见漫反射（UV-VIS）等分析方法对样品进行表征,并以甲基橙溶液模拟有机染料废水在可见光下评价其光催化降解能力。实验结果表明：与未掺杂Bi2O3纯相比,Zr掺杂Bi2O3仍为β-Bi2O3相组成,晶粒尺寸减小,颗粒大小约20nm。共沉淀合成使Zr组分均匀进入Bi2O3晶格形成固溶体。随Zr掺杂量增加,晶格畸变使样品紫外-可见吸收峰红移,带隙能减小,光催化性能增强,其中以Zr与Bi物质的量之比为20∶80的样品光催化性能最好。该样品在可见光下照射1h对甲基橙降解率达96%,降解速率为16.74mg/（h·g）,是商品P25型纳米TiO2的41倍。Zr掺杂Bi2O3对甲基橙的降解以光生空穴直接氧化为主,光生电子与氧反应生成·OH的氧化为必要的补充。The undoped and zirconium-doped bismuth oxide photocatalysts were prepared via coprecipitation processwith bismuth nitrate and zirconyl nitrate as raw materials and aqueous ammonia as precipitator.The as-prepared sampleswere characterized by X-ray diffraction（XRD）,transmission electron microscope（TEM）,UV-VIS diffuse reflectancespectra,respectively.And the photocatalytic reaction efficiency was evaluated using methyl orange as simulatedpollutant.The results show that zirconium-doped Bi2O3 particles with a certain concentration Zr^（4＋）solid solution are stillβ-Bi2O3 phase,which is consistent with the phase composition of the undoped bismuth oxide.The doping effects of Zr^（4＋）into Bi2O3 led to the decrease of the particle size to a certain extent.The particle sizes of Zr^（4＋）-doped Bi2O3 are about 20 nm,compared with 27 nm of undoped Bi2O3.The uniform Zr distribution in the particles was achieved by thecoprecipitation process,and Zr^（4＋）ions entered into Bi2O3 lattice structure and formed solid solution.The increasedconcentration of zirconium into Bi2O3 lattice enhances the lattice distortion of Bi2O3 crystal.So the absorption edges of Zrdoped Bi2O3 samples shift to the visible light range,the band gap energy Eg of the samples decrease and thephotocatalytic degradation efficiency increase correspondingly.The results reveal that the sample with Zr∶Bi mole ratio of20∶80 exhibited the best photocatalytic performance.And the total degradation of methyl orange（MO）is up to 96%,the degradation rate is 16.7 mg/（h·g）under visible light irradiation for 1 h,which increase 41 times greater than that oncommercial P25.The photocatalytic degradation mechanism of MO is mainly due to the direct oxidation of light inducedvacancies,actually the light induced electrons react with oxygen to form hydroxyl radical,which is the necessarycomplement for oxidation of MO degradation.

关 键 词：氧化铋 共沉淀 光催化 甲基橙 降解 

分 类 号：O614.53[理学—无机化学] TQ032.41[理学—化学]