Wang Jinling, Tsai Meng-Che, Lu Zhenying, Li You, Huang Guangtuan, Wang Hualin, Liu Honglai, Liao Xiaoyong, Hwang Bing-Joe, Neumann Anke, Yang Xuejing
National Engineering Laboratory for Industrial Wastewater Treatment and State Key Laboratory of Chemical Engineering, East China University of Science and Technology (ECUST), Shanghai 200237, China.
NanoElectrochemistry Laboratory, Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
ACS Omega. 2019 Dec 9;4(26):21945-21953. doi: 10.1021/acsomega.9b03008. eCollection 2019 Dec 24.
In this study, we prepared polyaniline-intercalated iron oxychloride (FeOCl-PANI) by aqueous intercalation method to use it as a Fenton-like catalyst that was then assessed in terms of behavior of intercalation, structural evolution, Fenton-like activity, and catalytic mechanism. Gel-permeation chromatography demonstrated that the molecular weight (polymerization extent) of polyaniline fragment gradually increased with the increase of intercalation time. Interestingly, the polyaniline-intercalated materials with varying intercalation times exhibited distinctly different Fenton-like activity trends under acidic (pH 4) and neutral (pH 7) conditions. Specifically, Fenton-like degradation is favored with a shorter intercalation time under acidic conditions, while it is preferred with a longer intercalation time under neutral pH values. We propose that an additional pH-dependent charging of FeOCl-PANI with different polymerization extents of the intercalated polyaniline promotes a switch in the contaminant degradation pathway, leading to opposite trends in observable activity at different pH values. As a class of typical layered metal chalcogenohalides (MeAX, A = O, S, Se, X = Cl, Br, I), FeOCl-PANI is expected to provide new insights into the development of other similar materials. This work could be useful to further understand the HO heterogeneous activation behavior, which is of significance to the application of iron-based heterogeneous Fenton oxidation.
在本研究中，我们通过水相插层法制备了聚苯胺插层的氯氧化铁（FeOCl-PANI），并将其用作类芬顿催化剂，随后从插层行为、结构演变、类芬顿活性和催化机理等方面对其进行了评估。凝胶渗透色谱表明，聚苯胺片段的分子量（聚合程度）随着插层时间的增加而逐渐增大。有趣的是，在酸性（pH 4）和中性（pH 7）条件下，不同插层时间的聚苯胺插层材料表现出明显不同的类芬顿活性趋势。具体而言，在酸性条件下，较短的插层时间有利于类芬顿降解，而在中性pH值下，较长的插层时间更有利于降解。我们认为，插层聚苯胺聚合程度不同的FeOCl-PANI额外的pH依赖性电荷促进了污染物降解途径的转变，导致在不同pH值下观察到的活性呈现相反趋势。作为一类典型的层状金属卤化物（MeAX，A = O、S、Se，X = Cl、Br、I），FeOCl-PANI有望为其他类似材料的开发提供新的见解。这项工作有助于进一步理解羟基自由基的非均相活化行为，这对铁基非均相芬顿氧化的应用具有重要意义。
