Hierarchically porous silica as an efficient catalyst carrier for high performance vis-light assisted Fenton degradation

A kind of hierarchically porous silica (HPS) was used as an efficient catalyst carrier to load iron oxide small particles. The obtained Fe2O3/HPS hybrids were characterized by SEM, EDS, XRD, XPS, N-2 adsorption-desorption isotherms, DFT and Hg porosimetry. The catalytic activity of the Fe2O3/HPS was evaluated by the degradation of azo-dye Orange II. The Fe2O3/HPS showed high catalytic activity to the photo-Fenton reaction with vis-light (lambda > 400 nm) irradiation. More than 90% of dye in solution could be degraded. The effects of pH, H2O2 concentration, additive (hydroxylamine hydrochloride), leaching and stability tests were studied. The Fe2O3/HPS could work well in a wider pH range (2.5-8.5) than common homogeneous iron catalyst. Due to the excellent pore structure of HPS, Fe2O3/HPS exhibited much better catalytic ability than normal commercial hematite (Fe2O3) under the same experimental condition. Moreover, Fe2O3/HPS had an ideal stability for the degradation of Orange II after at least ten recycles. (C) 2013 Elsevier Inc. All rights reserved.