Photoelectrocatalytic degradation of 4-chlorophenol at Bi2WO6 nanoflake film electrode under visible light irradiation
Photoelectrocatalytic degradation of 4-chlorophenol at Bi2WO6 nanoflake film electrode under visible light irradiation
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DOI：
10.1016/j.apcatb.2006.10.006
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发表时间：
2007-03
影响因子：
22.1
通讯作者：
Xu Zhao;Tongguang Xu;W. Yao;Chuang Zhang;Yongfa Zhu
中科院分区：
文献类型：
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作者：
Xu Zhao;Tongguang Xu;W. Yao;Chuang Zhang;Yongfa Zhu
为了有效利用太阳光并改进废水净化的光氧化技术，通过静电自组装沉积将一种新型光电极——可见光响应Bi2WO6纳米片薄膜覆盖在氧化铟锡玻璃基板上。研究并比较了可见光照射（λ>400nm）下薄膜电极对水溶液中4-氯苯酚（4-CP）的光催化氧化、电氧化和光电催化（PEC）氧化。实验结果表明，在可见光照射或施加大于0.8V的偏压电位下，4-CP可以被纳米片薄膜降解。根据电化学反应后电极的X射线光电子能谱（XPS）分析，表明电氧化过程中发生了电聚合。此外，电氧化和光催化相结合大大提高了4-CP的降解效率。并且，在偏置电位2.0V时最大。还通过电化学阻抗谱（EIS）研究了4-CP的PEC降解特性。 EIS 表明，PEC 降解似乎是电极表面上的一种简单反应，表明电极过程中只涉及一个电荷转移步骤。总有机碳分析表明4-CP在PEC过程中可以被有效矿化。
To efficiently utilize the solar light and improve the photooxidation technique for wastewater purification, a new type of photoelectrode, visible light responsive Bi2WO6nanoflake film, was covered onto the indium–tin oxide glass substrate via the electrostatic self-assembly deposition. The photocatalytic oxidation, electro-oxidation, and photoelectrocatalytic (PEC) oxidation of 4-chlorophenol (4-CP) in aqueous solution using the film electrode were investigated and compared under visible light irradiation (λ>400nm). The experimental results demonstrated that 4-CP could be degraded by the nanoflake film under visible light irradiation or by applying a bias potential greater than 0.8V. Based on X-ray photoelectron spectra (XPS) analysis of the electrode after electrochemical reaction, the electropolymerization was suggested to occur in the electro-oxidation process. Furthermore, degradation efficiency of 4-CP was largely increased by combined electro-oxidation and photocatalysis. And, it is the largest at the bias potential of 2.0V. The characteristics of the PEC degradation of 4-CP were also investigated by electrochemical impedance spectroscopy (EIS). It is shown from the EIS that the PEC degradation appears to be a simple reaction on the electrode surface, suggesting that only one step of charge transfer is involved in the electrode process. The total organic carbon analysis indicated that 4-CP could be efficiently mineralized during the PEC process.