Visible Light Assisted Heterogeneous Fenton-Like Degradation of Organic Pollutant via α‑FeOOH/Mesoporous Carbon Composites

• Published in: Environmental science & technology 2017-04, Vol.51 (7), p.3993-4000
• Main Authors: Qian, Xufang, Ren, Meng, Zhu, Yao, Yue, Dongting, Han, Yu, Jia, Jinping, Zhao, Yixin
• Format: Article
• Language: English
• Subjects: Active sites; Carbon; Catalysis; Catalysts; Composite materials; Crystallization; Efficiency; Environmental degradation; Environmental Pollutants - chemistry; Ferric Compounds; Ferric hydroxide; Ferric ions; Hydrogen Peroxide; In situ leaching; Iron; Irradiation; Leaching; Light; Light irradiation; Microcrystals; Mineralization; Nanocrystals; Oxidation; Phenols; Photocatalysis; Photodegradation; Pollutants; Synergistic effect; α Radiation
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.6b06429

A novel α-FeOOH/mesoporous carbon (α-FeOOH/MesoC) composite prepared by in situ crystallization of adsorbed ferric ions within carboxyl functionalized mesoporous carbon was developed as a novel visible light assisted heterogeneous Fenton-like catalyst. The visible light active α-FeOOH nanocrystals were encapsulated in the mesoporous frameworks accompanying with surface attached large α-FeOOH microcrystals via C–O–Fe bonding. Assisting with visible light irradiation on α-FeOOH/MesoC, the mineralization efficiency increased owing to the photocatalytic promoted catalyzing H2O2 beyond the photothermal effect. The synergistic effect between α-FeOOH and MesoC in α-FeOOH/MesoC composite improved the mineralization efficiency than the mixture catalyst of α-FeOOH and MesoC. The iron leaching is greatly suppressed on the α-FeOOH/MesoC composite. Interestingly, the reused α-FeOOH/MesoC composites showed much higher phenol oxidation and mineralization efficiencies than the fresh catalyst and homogeneous Fenton system (FeSO4/H2O2). The XPS, XRD, FTIR, and textural property results reveal that the great enhancement comes from the interfacial emerged oxygen containing groups between α-FeOOH and MesoC after the first heterogeneous Fenton-like reaction. In summary, visible light induced photocatalysis assisted heterogeneous Fenton-like process in the α-FeOOH/MesoC composite system improved the HO• production efficiency and Fe­(III)/Fe­(II) cycle and further activated the interfacial catalytic sites, which finally realize an extraordinary higher degradation and mineralization efficiency.