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Chinese Journal of Catalysis 37 (2016) 2079–2085 催化学报 2016年 第37卷 第12期 | available at journal homepage: Article Electro‐polymerization fabrication of PANI@GF electrode and its energy‐effective electrocatalytic performance in electro‐Fenton process Jinli Yu a, Tianfu Liu b, Haiyue Liu b, Yi Wang b,* a The Key Lab of Low‐Carbon Chemistry & Energy Conservation of Guangdong Province, School of Materials Science and Engineering, Sun Yat‐sen University, Guangzhou 510275, Guangdong, China b School of Chemical Engineering and Technology, Sun Yat‐sen University, Zhuhai 519082, Guangdong, China ARTICLE INFO ABSTRACT Article history: Received 18 August 2016 Accepted 8 September 2016 Published 5 December 2016 An energy‐effective polyaniline coated graphite felt (PANI@GF) composite cathode for the elec‐tro‐Fenton (E‐Fenton) process was synthesized through an electro‐polymerization method. The electrocatalytic activity of the cathode for the 2e− ORR process was investigated and dimethyl phthalate (DMP) was used as a model substrate to evaluate its performance in the E‐Fenton process. The as‐prepared PANI@GF composite possessed a three‐dimensional porous structure, which is favorable for O2 diffusion, while the large amount of N atoms in the conductive polyaniline (PANI) enhanced 2e− ORR reactivity. The DMP degradation of the E‐Fenton system using PANI@GF was significantly enhanced owing to the improvement in ORR performance. The apparent kinetic con‐stant for DMP degradation was 0.0753 min–1, five times larger than that of GF. The optimal carboni‐zation temperature and polymerization time for the preparation of the PANI@GF composite cath‐ode was found to be 900 °C and 1 h, respectively. Measurement conditions are a crucial factor for proper evaluation of cathode electrocatalytic performance. Accordingly, the O2 flow rate, Fe2+ con‐centration, and pH for DMP degradation were optimized at 0.4 L/min, 1.0 mmol/L, and 3.0, respec‐tively. These results indicate that the present PANI@GF composite cathode is energy‐effective and promising for potential use as an E‐Fenton system cathode for the removal of organic pollutants in wastewater. © 2016, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.Published by Elsevier B.V. All rights reserved.Keywords: Electrocatalysis Oxygen reduction reaction Electro‐polymerization Electro‐Fenton Dimethyl phthalate degradation 1. Introduction The electro‐Fenton process (E‐Fenton) [1–4], one of the ad‐vanced oxidation processes (AOPs), has been shown to be a promising technology for degrading refractory pollutants in wastewater [5–10]. The process is a simple electrochemical reaction process. First, H2O2 is generated from the reduction of O2 through a 2e− process without additional acquisition, ship‐ment, or storage (Eq. 1). Subsequently, Fe2+ is added to the sys‐tem to react with the H2O2 to generate hydroxyl radicals (•OH) (Eq. 2). The hydroxyl radicals, which have a high electrode po‐tential (2.8 V vs. standard hydrogen electrode (SHE)), can rap‐idly non‐selectively destroy refractory pollutants [11–13]. O2 + 2H+ + 2e− H2O2 0.695 V (vs. SHE) (1) * Corresponding author. Tel: +86‐20‐84110930; Fax: +86‐20‐84113253; E‐mail: wangyi76@mail.sysu.edu.cn This work was supported by the Sino‐Greek Science and Technology Cooperation Project (2013DFG62590), the National Natural Science Foundation of China (21575299, 21576300, 21276290), Guangdong Province Nature Science Foundation (2014A030313150), and Guangzhou Science and Technology Plan Project (201607010104). DOI: 10.1016/S1872‐2067(16)62525‐1 | | Chin. J. Catal., Vol. 37, No. 12, December 2016 2080 Jinli Yu et al. / Chinese Journal of Catalysis 37 (2016) 2079–2085 Fe2+ + H2O2 •OH + OH− + Fe3+ (2) In the E‐Fenton process, H2O2 is first generated at the cath‐ode through the 2e− oxygen reduction reaction (ORR) process [14,15]. So, improvement of the efficiency of ORR for H2O2 production is crucial for E‐Fenton systems [16]. The cathode material can greatly influence the mechanism and kinetics of ORR [17,18]. At present, carbonaceous materials have been widely investigated for their excellent ORR reactivity, with ad‐vantages such as high overpotential for hydrogen evolution, non‐toxicity, low cost, and good stability. Carbonaceous mate‐rials such as graphite, carbon felt, graphite felt, carbon sponge, activated carbon fiber, and carbon‐polytetrafluoroethylene (PTFE) composite electrodes are widely used in E‐Fenton sys‐tems [19–25]. Among them, graphite felt (GF), already a com‐mercialized cathode material, shows promising advantages such as a 3D interconnected structure that provides abundant active sites and rapid mass‐transfer, outstanding anti‐corrosion resistance, mechanical integrity in flexible electrodes, and ease of manufacture for large‐scale applications [21]. Accordingl