In-situ establishment of binary composites α-Fe2O3/Bi12O17Cl2 with both photocatalytic and photo-Fenton features

Abstract

A set of binary composites α-Fe₂O₃/Bi₁₂O₁₇Cl₂ were established through an in-situ deposition route and these samples were systematically characterized by a collection of analytical techniques. Scanning electron microscopy, UV-vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy proved the coexistence of expected two components. High resolution transmission electron microscopy and selected-area electron diffraction indicated the formation of heterojunction domains with the intimate contact of both semiconductors. The degradation behavior of as-synthesized samples was evaluated under visible-light irradiation and the enhanced outcome was observed over dye methyl orange (MO) and colorless 2,4-dichlorophenol (2,4-DCP), mainly attributing to favorable optical and morphological merits, and a suitable well-aligned band structure in these binary composites with a suitable phase composition as well. In addition, these composites showed an obvious photo-Fenton feature that significantly improved the catalytic degradation efficiency over 2,4-DCP when the reagent H₂O₂ was introduced, indicating the destruction efficiency was controlled by a synergtic effect from both photocatalytic and photo-Fenton degradation routes. Based upon the detection of reactive radical species, a primary synergistic mechanism was eventually speculated.

Keywords: Bi(12)O(17)Cl(2); Binary composites; Mechanism; Photo-Fenton; Photocatalytic; α-Fe(2)O(3).