Role of exposed facets and surface OH groups in the Fenton-like reactivity of lepidocrocite catalyst

Heterogeneous Fe-based Fenton-like reaction is an efficient technology in wastewater treatment. However, few studies reveal the effects of exposed facets and surface OH groups of iron oxides on its reactivity. In this study, two lepidocrocite samples with lath- and rod-like morphologies were synthesized and applied to the adsorption and degradation of Orange G (OG). The OG molecule could be adsorbed vertically on the lath-like sample by the interaction with the mu-OH groups of the (010) facet. The molecule could also be adsorbed laterally on the rod-like sample by the interactions with the mu-OH and mu(3)-OH groups of the (010) and (001) facets. When the data were normalized to the unit surface area, the adsorption capacity of OG, the production efficiency of center dot OH, the degradation rate in dark, and the total degradation rates under visible light irradiation in the lath-like system were 9.625-, 3.34-, 2.75-, and 1.98-fold higher than those in the rod-like system, respectively. (C) 2019 Elsevier Ltd. All rights reserved.