Heterostructured TiO2@HKUST-1 for the enhanced removal of methylene blue by integrated adsorption and photocatalytic degradation

Abstract

Aiming at exploring an effective photocatalytic adsorbent for organic dye removal, a series of heterostructured TiO₂@HKUST-1 photocatalysts, by incorporating HKUST-1 with different TiO₂ nanoparticles loading, were prepared by single-step hydrothermal method. The morphology and surface characteristics of the as-prepared TiO₂@HKUST-1were analyzed using SEM, HRTEM, XRD, FTIR, UV-vis DRS, and Photoluminescence techniques. The adsorption-photocatalytic degradation of the model dye methylene blue (MB) on the catalysts was investigated. It was indicated that the introduction of a certain amount of TiO₂ on the surface of HKUST-1 could improve the transfer and separation of the photogenerated charge carriers, resulting in the enhanced photocatalytic activity. The optimal 0.02TiO₂@HKUST-1 exhibited the highest MB removal rate with about 4.4 and 19.3 times as high MB removal efficiency as that of HKUST-1 and TiO₂, respectively. Heterostructured TiO₂@HKUST-1 materials for the removal of MB involved the integrated adsorption and visible light photocatalysis. Meanwhile, the composite exhibited good reusability in the process of cyclic experiments. Therefore, this work provides a potential MOF-based photocatalytic adsorbent for organic dye removal.

Keywords: TiO2@HKUST-1; adsorption; methylene blue; photocatalytic degradation.