Assessment of tailor-made mesoporous metal doped TiO2 monolithic framework as fast responsive visible light photocatalysts for environmental remediation applications

摘要

The article reports on the facile one-pot synthesis of a structurally organized mesoporous crack-free monolithic network of Bi3+ doped TiO2, as a visible light workable photocatalyst materials for environmental remediation. The monolithic photocatalyst efficacy has been investigated using Acid Blue 113, an organic textile dye as the model organic pollutant, thereby rooting its decontamination potential towards dye effluents from textile and dye industries. The controlled stoichiometric surface doping of Bi3+ with the continuous framework of the TiO2 monolithic material not only ensures visible light-induced photocatalysis but also high quantum yield upon light impingement thereby leading a rapid generation of reactive radical species. The monolith structural properties and its morphology are characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED), energy dispersive X-ray spectrometry (EDAX), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PIS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and N-2 adsorption-desorption isotherm analysis. The anatase phase TiO2 monolith offers a high surface area that promotes the voluminous generation of photo-induced e(-)/h(+) pairs that proceed towards the formation of reactive radical intermediates for the fast dissipation of pollutants. To valid the efficiency and effectiveness of the Bi3+ doped TiO2 monolith photocatalyst, a comprehensive study on the physicochemical parameters such as solution pH, dopant stoichiometry, photocatalyst quantity, light intensity, photosensitizers, and reusability, proves crucial. The results reveal that under optimized conditions, the photocatalyst has an ultra-fast response time of <= 0.2 h for complete mineralization, with 0.06 g of monolithic photocatalysts that are recoverable and reusable.