摘要
为了研究氧化铟及不同Bi^(3+)掺杂量的氧化铟改性材料的光催化性能,采用溶剂热法制备了氧化铟和掺杂不同比例Bi^(3+)的氧化铟光催化剂,并通过X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线电子能谱(EDS)、比表面积(BET)分析等方法对其结构及性质进行了表征。结果表明,当Bi^(3+)掺杂量小于或等于10%(摩尔分数)时,Bi^(3+)的掺杂对氧化铟纳米球的晶型结构和结晶度基本不产生影响;而当掺杂量大于10%时,晶体结构发生变化;Bi^(3+)的掺杂进一步增大了氧化铟纳米球的比表面积和孔容,掺杂后氧化铟纳米球的N2吸附-脱附等温线为典型的IUPAC(国际纯粹与应用化学联合会)IV型等温线。以紫外灯(波长λ=254 nm)为光源,以直接大红为目标降解物,考察了不同Bi^(3+)掺杂量的氧化铟的光催化性能。结果表明:Bi^(3+)掺杂量为8%时,氧化铟对直接大红废水去除效果最佳,去除率高达94.3%,光催化剂活性最高;光催化降解直接大红的过程完全符合一级反应动力学方程;同时,活性物种捕获试验证明了加入10 m L异丙醇,反应中光降解率只有很小的下降,表明羟基自由基(·OH)不是光催化体系中的主要活性物种,而空穴(h+)才是光催化氧化直接大红过程中的主要活性物种。研究表明,通过元素掺杂可以很好地改变氧化物的光催化性能。
The paper is to present a new approach to Bi doped modification of indium oxide through synthesis of indium oxide and Bi-series doped indium oxide photocatalysts with the solvothermal method, and their corresponding structure and photoeata- lytic properties have been studied by using XRD, SEM, EDS and BET. As is known, toxic harmful materials in water can be oxidized to CO2, H2O and other nontoxic organics via photocatalytic technology through efficient oxidation. The characterization results we have gained show that, the doping of Bi3＋ has no obvious effect on the crystal structure or the crystalline of In2O3 nano-sphere as the doping content is less than or just equal to 10% , whereas doping more content tends to lead to the variations of the crystal structure. What is more, the diameter of Bi - lnNSs - 8 solid nanospheres is slightly less than that of IntO3 nanosphere, whereas the doping of Bi3 ＋ is likely to increase the specific surface and the pore volume of In203nanosphere ulteriorly. Moreover, the nitrogen adsorption-desorption isotherm tends to exhibit a type IV adsorption isotherm. Therefore, in our experiments, we have chosen Congo red as the objective pollutant so as to assess the photo- catalytic performance of In2 O3 in different doping contents under UV irradiation （λ=254 nm）. The experimental results we have gained show that： when the doping content is 8%, it would be possible for Congo red to gain the optimal degradation perform- ance, with the degradation rate being possible to reach 94. 3%. Meanwhile, the process of Congo red photocatalytic degradation can be well in accord with the first-order kinetics equation, whereas the photocatalytic activity of 8% can be said greatest as compared with other catalysts prepared in the experiment. Thus, adding 10 mL of isopropanol has been found leading to a slightly reduced degradation rate of Congo red through the active species capture experiment, which can further indicate less effect of ·OH radicals on the process of its photocatalytic oxi
作者
赵平歌
张格红
周孝德
汪文博
ZHAO Ping-ge ZHANG Ge-hong ZHOU Xiao-de WANG Wen-bo(Institute of Water Resources and Hydro-electric Engineering, Xi＇an University of Technology, Xi＇an 710045, China School of Civil ＆ Architecture Engineering, Xi＇an Technological Univer- sity, Xi＇an 710021 , China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第6期224-228,共5页
Journal of Safety and Environment
基金
陕西省教育厅科研计划项目(15JK1369)
关键词
环境工程学
掺杂
氧化铟
直接大红
活性物种
environmental engineering
doping
indium oxide
Congo red
active species
