Ionic liquid-assisted fabrication of metal–organic framework-derived indium oxide/bismuth oxyiodide p-n junction photocatalysts for robust photocatalysis against phenolic pollutants

• Published in: Journal of colloid and interface science Vol. 606; pp. 1261 - 1273
• Main Authors: Sun, Meng, Li, Fengli, Zhao, Fulei, Wu, Tingting, Yan, Tao, Du, Bin, Li, Danzhen
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15-01-2022
• Subjects: Heterojunction; In2O3/BiOI; Phenolic pollutants; Photocatalyst; Visible light; Visible light; In2O3/BiOI; Photocatalyst; Phenolic pollutants; Heterojunction
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2021.08.132

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•MOF-derived In2O3/BiOI photocatalysts were fabricated by ionic liquid-assisted method.•The sample shows efficient activity in decomposing OPP and PTBP.•The OPP degradation rate over In2O3/BiOI-2 was 5.67 times higher than that of BiOI.•Promoted charge separation and visible light absorption result in the higher activity.
Constructing a p–n heterojunction is a feasible strategy to manipulate the dynamic behaviors of photogenerated carriers through an internal electric field. Herein, a novel highly efficient indium oxide/bismuth oxyiodide (In2O3/BiOI) p–n junction photocatalyst was fabricated using a facile ionic liquid-assisted precipitation method for the first time. The morphologies were modified by adding different amounts of acetic acid solution. Their hierarchical architecture was beneficial for adsorbing contaminants in wastewater, while the in-situ formed p-n heterojunction between BiOI and In2O3 facilitated interfacial charge transfer and improved the quantum efficiency. Their visible light-responsive photocatalytic activities were systematically investigated by photocatalytic o-phenylphenol (OPP) and 4-tert-butylphenol (PTBP) oxidation. The degradation rate of OPP over In2O3/BiOI-2 was up to 5.67 times higher than that for BiOI. The excellent activity of In2O3/BiOI should be attributed to the rapid interfacial charge transfer, depressed carrier recombination, and proper band potentials. Trapping experiments and electron paramagnetic resonance characterizations confirmed the generation of hydroxyl radicals (•OH) and superoxide radicals (•O2–), which have played a key role in decomposing pollutants. The intermediate products generated during the photocatalytic degradation of OPP were detected and identified by liquid chromatography-mass spectrometry. Meanwhile, their possible molecular structures and degradation pathways have also been inferred.