研究报告

  • 徐秋鹏,张力琳,李佳汶,李瑞桢,王成端,肖琳川.CuFeO2耦合过硫酸盐可见光催化降解过程及机理研究[J].环境科学学报,2018,38(6):2350-2359

  • CuFeO2耦合过硫酸盐可见光催化降解过程及机理研究
  • Studies on the visible-light photocatalytic degradation process and mechanism by using CuFeO2 coupling persulfate
  • 基金项目:国家自然科学基金(No.61601313);四川省教育厅重点项目(No.16ZA0261);四川理工学院人才引进项目(No.2015RC02);过程装备与控制工程四川省高校重点实验室项目(No.GK201611)
  • 作者
  • 单位
  • 徐秋鹏
  • 1. 四川理工学院化学与环境工程学院, 自贡 643000;2. 四川理工学院化学工程学院, 自贡 643000
  • 张力琳
  • 四川理工学院化学与环境工程学院, 自贡 643000
  • 李佳汶
  • 四川理工学院化学与环境工程学院, 自贡 643000
  • 李瑞桢
  • 四川理工学院化学与环境工程学院, 自贡 643000
  • 王成端
  • 四川文理学院化学化工学院, 达州 635000
  • 肖琳川
  • 信息产业电子第十一设计研究院科技工程股份有限公司, 成都 610000
  • 摘要:采用水热合成法制备了CuFeO2催化剂,并采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、X射线能谱仪(EDS)、比表面分析仪和紫外可见漫反射光谱(DRS)对CuFeO2催化剂的晶体结构、表面形貌、组成元素、比表面积及禁带宽度等特性进行了表征分析.同时,以CuFeO2为催化剂,加入过硫酸盐(PS),以模拟印染废水中的亚甲基蓝为目标污染物,在可见光照射下,耦合光催化技术与高级氧化技术,构建了CuFeO2/PS/可见光(Vis)体系,并将其应用于降解亚甲基蓝染料废水.结果表明,与Cu2O/PS/Vis、Fe2O3/PS/Vis体系相比,CuFeO2/PS/Vis体系在同等条件下具有更好的降解效果.为探究该体系的最佳操作条件和适用的pH范围,系统地考察了催化剂投加量、PS投加量、pH值等因素对亚甲基蓝降解效果的影响.总有机碳含量(TOC)和重复实验表明,CuFeO2可重复使用4次,该体系的降解效果基本不变,但矿化程度降低8.2%.电感耦合等离子体质谱(ICP-MS)实验结果表明,反应结束后溶液中残存1.7 mg·L-1 Cu(占CuFeO2投加总量的0.34%)和24.9 μg·L-1 Fe(占CuFeO2投加总量的0.05‰),推测其来自于CuFeO2中金属离子的溶出.此外,对反应后的CuFeO2进行XRD和SEM表征发现,其物相组成和形貌未明显变化,表明少量的金属溶解对材料稳定性的影响较小.结合自由基掩蔽实验和CuFeO2能带结构分析发现,该体系良好的降解效果首先得益于耦合反应过程中产生的SO4-·,其次是·OH,另外,还有CuFeO2受光激发产生的光生空穴及其表面键合的Cu(I)/Cu(Ⅱ)和Fe(Ⅱ)/Fe(Ⅲ)氧化还原对的协同作用.
  • Abstract:CuFeO2 was synthesized by hydrothermal method. The properties including crystalline structure, morphology, composition element, specific surface area and band gap of CuFeO2 were characterized by using X-ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), specific surface area analyzer and UV-Vis diffuse reflectance spectroscopy (DRS), respectively. Methylene blue (MB) was selected as the target contaminant. CuFeO2 was used as the catalyst and for activating persulfate (PS). The MB was successfully degraded by CuFeO2/PS/Visible-light (Vis) system which was attributed to the coupling of photocatalytic technology and advanced oxidation technology. Compared with Cu2O/PS/Vis and Fe2O3/PS/Vis system, the CuFeO2/PS/Vis system has better degradation efficiency of MB under the same conditions. In order to explored the optimum operating conditions and pH range of this system, the effects of the dosage of catalyst, the dosage of PS and the pH value on the degradation of MB were systematically investigated. The total organic carbon content (TOC) and the results of reuse experiment showed that the CuFeO2 can be re-collected and employed again for next use. After four cycles reuse, the degradation efficiency of MB did not changed, but the mineralization efficiency of MB was reduced by 8.2%. According to the results of the inductively coupled plasma mass spectrometries (ICP-MS), there were 1.7 mg·L-1 Cu and 24.9 μg·L-1 Fe in the reaction solution after degradation experiment, which are only 0.34% and 0.05‰ of the total amount of CuFeO2, respectively. It was presumed that Cu and Fe elements may be leached from CuFeO2. However, from the results of XRD and SEM, the composition and morphology of CuFeO2 were not changed obviously after four cycles reuse, indicating the leaching of small amounts of metal cation has little effect on the stability of CuFeO2. On the basis of the quenching experiment and the analysis of energy band structure of CuFeO2, the high degradation efficiency of MB in the CuFeO2/PS/Vis system can be firstly attributed to·SO4- generated in the coupling reaction process, then·OH, as well as the photogenerated holes and synergistic effect of Cu (I)/Cu (Ⅱ) and Fe (Ⅱ)/Fe (Ⅲ) redox pairs on the surface of CuFeO2.

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