Defective UiO-66 by metal doping for highly efficient photocatalytic degradation of methyl mercaptan

Abstract

Defective UiO-66 by metal doping exhibits considerable promise in the photocatalytic degradation of environmental contaminants, albeit how different metal doping affect formation of defects and its efficacy in the degradation of methyl mercaptan has yet to be comprehensively explored. In this study, a one-step solvothermal method was employed to successfully synthesize six distinct metal-doped UiO-66 with variations of defects by incorporating Ce, Al, Cu, Cr, Mg, and Fe. A systematic examination of the structural and photochemical attributes of these metal-doped UiO-66 materials was conducted through a series of characterisations. Metal doping creates defects in UiO-66, changes its colour and morphology and increases its specific surface area. Subsequently, the adsorption and photocatalytic degradation characteristics of these nanomaterials concerning methyl mercaptan were investigated. In comparison to pristine UiO-66, all metal-doped UiO-66 variants exhibited enhanced adsorption and photocatalytic degradation capabilities towards methyl mercaptan. Notably, among the prepared materials, FeUiO-66 demonstrated the most exceptional photocatalytic degradation performance, followed by CuUiO-66, AlUiO-66, CeUiO-66, CrUiO-66, and MgUiO-66 in that order. 1.0FeUiO-66 exhibiting the most remarkable performance, achieving a 99 % degradation of methyl mercaptan within 30 min. This represented a degradation rate 36.8 times higher than that of pure UiO-66, attributable to the incorporation of low-valence metals into the UiO-66 framework, resulting in the creation of oxygen vacancy defects. Furthermore, the presence of these metals facilitated electron transport, thereby enhancing the efficiency of photocatalytic degradation. This study underscores the potential of various metals-doped UiO-66 for adsorption and photocatalytic elimination of methyl mercaptan.