Preparation of Activated Carbon Fibers-α-FeOOH as a High-performance Heterogeneous Fenton-like Catalyst for Efficient Removal of Hydrotropic Lignin Model Compound

ACF-alpha-FeOOH composite material was prepared by ultrasound-assisted hydrothermal in-situ synthesis method and evaluated as a highly efficient heterogeneous Fenton-like catalyst. The ACF-alpha-FeOOH composite exhibited much stronger adsorption ability to hydrotropic lignin model pollutant (syringic acid) than that of alpha-FeOOH, which may be due to the higher specific surface area (ACF-alpha-FeOOH: 133.15 m(2) g(-1)>alpha-FeOOH: 18.77 m(2) g(-1)). The composite exhibited excellent heterogeneous Fenton-like catalysis activity, being influenced by the solution pH value and the proportions of alpha-FeOOH and ACF. Under optimal conditions, the ACF-alpha-FeOOH composite yielded fast degradation of syringic acid with an apparent rate constant of 0.151 min(-1), which were 3.97 and 33.56 folds of that achieved by using alpha-FeOOH and the mixture of alpha-FeOOH and ACF, respectively. And syringic acid was finally degraded to small molecules in the above reactive system due to the strong catalytic ability of the composite. The significantly enhanced heterogeneous Fenton-like catalytic properties of the ACF-alpha-FeOOH composite in comparison with that of alpha-FeOOH was attributed to smaller catalyst particle size, much increased adsorption capacity and the mass transfer of radical species between the catalyst and pollutants.