高级氧化和可见光照射协同作用下Bi2WO6对有机污染物降解的催化活性增强
Enhanced Catalytic Activity of Bi2WO6 for Organic Pollutants Degradation under the Synergism between Advanced Oxidative Processes and Visible Light Irradiation
汪园青 1潘育松 1朱红梧 1向妍蕾 1韩蓉 1黄润 1杜超 1潘成岭1
作者信息
- 1. 安徽理工大学材料科学与工程学院,安徽 淮南 232001
- 折叠
摘要
随着工业化社会的不断发展,环境问题日益严重.尤其是工业废水问题一直是催化降解领域的研究热点.光催化与高级氧化工艺(AOPs)耦合技术因为具有高效、无选择性、处理条件温和等特点,被认为是一种高效的有机污染物降解技术.本文以十六烷基三甲基溴化铵(CTAB)表面活性剂作为模板,采用简单的水热法制备了钨酸铋(Bi2WO6)纳米花.通过X射线衍射(XRD)、傅里叶红外光谱(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见漫反射光谱(DRS)技术对其微观形貌、晶相、表面化学元素状态和光学性质进行了表征.为了研究钨酸铋(Bi2WO6)纳米花的催化性能,在不同催化体系下降解有机污染物罗丹明B(RhB),实验发现,于vis/过硫酸盐(PMS)/Bi2WO6体系下,40 min内对RhB的去除率高达96.39%,明显优于PMS/Bi2WO6(40 min内去除率为38.77%)和vis/Bi2WO6(40 min内去除率为31.82%)体系,表明可见光照射和PMS的协同作用加速了Bi2WO6对RhB降解的催化活性.此外,还研究了催化剂剂量、PMS浓度、pH值和离子浓度等环境参数对催化体系催化性能的影响.结果表明,环境参数对vis/PMS/Bi2WO6系统中RhB的去除率影响不大,RhB的去除率也高达90%.相反,环境参数对vis/PMS/Bi2WO6体系下催化降解率(K)有明显影响,K值会随着催化剂剂量和PMS浓度的增加而增大.在pH不同环境下,K值会随着催化体系中pH值的升高,先增大后减小.当催化体系中的pH = 7时,催化降解率达到最大值(0.1502 min-1).有趣的是,体系中Cl-的存在有利于提高催化降解效率.相反,体系中CO32-的存在会明显抑制催化降解效率.循环实验的结果也验证了催化剂在降解有机染料方面具有良好的稳定性.此外,淬灭实验和EPR测试结果表明,超氧自由基(·O-2)和单线态氧(1O2)对有机污染物的降解起着重要作用.Bi2WO6在vis/PMS协同催化体系中的优异催化活性得益于其显著的可见光响应下光催化活性和铋离子对PMS的超强活化能力.
Abstract
Environmental problems have become more and more serious with the continuous development of industrialized society.Especially,the problem of industrial wastewater has been a hot research issue in the field of catalytic degradation.Coupling photocatalysis and advanced oxidation processes(AOPs)is considered to be an efficient organic pollutant degradation technology due to its high efficiency,non-selectivity,and mild treatment conditions.In this article,the authors focused on the synthesis and characterization of Bismuth tungstate(Bi2WO6)nanoflowers,which were prepared using a straightforward hydrothermal method in the presence of cetyltrimethylammonium bromide(CTAB)surfactant.To investigate the micro-morphology,crystal phase,surface chemical element states,and optical characteristics of the Bi2WO6 nanoflowers,various methods such as X-ray diffraction(XRD),Fourier transform infrared(FTIR),scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),and diffuse reflection spectroscopy(DRS)were used.The catalytic performance of the Bi2WO6 nanoflowers was then investigated for degrading organic pollutants under different catalytic systems.The removal efficiency of Rhodamine B(RhB)was up to 96.39%within 40 min under vis/potassium monopersulfate triple salt(PMS)/Bi2WO6 system,which is obviously superior to that in both PMS/Bi2WO6(38.77%in 40 min)and vis/Bi2WO6(31.82%in 40 min)systems,indicating that synergistic effects between visible-light irradiation and PMS accelerated the catalytic activity of Bi2WO6 on the RhB degradation.The researchers also investigated the effect of ambient conditions on the catalytic performance of the systems,such as catalyst dosage,PMS concentration,pH value,and ion concentration.Interestingly,the vis/PMS/Bi2WO6 system demonstrated high removal efficiency(up to 90%)despite changes in these parameters.However,the catalytic degradation rate(k)was influenced by these parameters in this system.Conversely,the environmental parameters have obvious influence on the catalytic degradation rate(k)under vis/PMS/Bi2WO6 system.The results showed that when the catalyst dosage and PMS concentration increased,so did the K value.On the other hand,the K value increased firstly and then decreased with the rise of pH value in the catalytic system.And the catalytic degradation rate reached its maximum value(0.1502 min-1)at pH = 7 in the catalytic system.Interestingly,the presence of Cl-in the system would be beneficial for promoting the catalytic degradation efficiency.Conversely,the existence of CO32-in the system would obviously inhibit the catalytic degradation efficiency.The result of the cycling experiments also verified that the catalyst possessed excellent stability for the degradation of organic dyes.Furthermore,the researchers conducted quenching experiments and EPR(electron paramagnetic resonance)tests,which revealed the crucial roles of superoxide radicals(·O-2)and singlet oxygen(1O2)in the degradation of organic pollutants.Overall,the excellent catalytic activity of Bi2WO6 in the vis/PMS synergistic catalytic system was attributed to its outstanding visible-light-response photocatalysis activity and the superior ability of bismuth ions in activating PMS.
关键词
光催化/高级氧化过程/Bi2WO6/过硫酸盐/罗丹明BKey words
Photocatalysis/Advanced oxidation processes/Bi2WO6/Peroxymonosulfate/Rhodamine B引用本文复制引用
基金项目
安徽省自然科学基金(2108085MB44)
安徽理工大学研究生创新基金(2022)(2022CX2101)
出版年
2024
国家科技期刊平台
NSTL
万方数据