Unveiling the synergistic effect of ionic liquid and metal-organic framework on the efficiency of BiVO4: BiVO4-MIL-100(Fe) as a visible light-induced photocatalyst for Basic Red 46 degradation

Abstract

Here, the effect of three different ionic liquids (IL) on the structural properties and photocatalytic activity of Bismuth Vanadate (BiVO4) was investigated. In this regard, BiVO4 hydrothermally synthesized in the presence of three different ionic liquids, including 2-hydroxyethyl ammonium formate, 1-Ethyl-3-methylimidazolium ethyl sulfate [Emim][EtSO4], and 1-Butyl-3-methylimidazolium methanesulfonate, [C4mim][MeSO3]. Additionally, the effect of calcination temperature was also studied by calcining hydrothermally synthesized BiVO4 at 600 °C, and all results were compared to a pure sample containing no IL. According to the characterization results, monoclinic scheelite-phase BiVO4 was only obtained in the presence of [Emim][EtSO4] and a higher temperature of 600 °C. To improve photocatalytic activity, the hybrid structure of IL-assisted BiVO4 with MIL-100 (Fe) was constructed by the in-situ growing of MIL-100(Fe) on the surface of BiVO4 and employed as a photocatalyst for the degradation of Basic Red 46. The IL-BiVO4-MIL-100(Fe) hybrid material exhibited higher photocatalytic activity than bare BiVO4, degrading more than 88% of Basic Red 46 in 120 min. To identify the photodegradation compounds and to determine the environmental fate of Basic Red 46, gas chromatography-mass spectrometry (GC–MS) was employed, and the possible degradation mechanism was discussed and proposed.