Enhanced photocatalytic degradation of methylene blue and adsorption of metal ions by SDS-TiP nanocomposite

Abstract

Abstract: In this paper, a facile and highly efficient nanocomposite sodium dodecyl sulphate-based titanium(IV) phosphate (SDS-TiP) was successfully synthesized by sol–gel method. The surface morphology, crystalline structure, and optical properties were characterized by FTIR, XRD, TGA-DTA, SEM, TEM and UV–Vis diffuse reflectance spectroscopy (DRS). The physiochemical properties such as pH titration, elution behavior and chemical stability of SDS-TiP were studied. The ion exchange capacity of SDS-TP was found to be higher (1.6 meq g−1) for Na+ ion as compared to their non-SDS material (1.1 meq g−1). For optimal adsorption of metal ions, sorption studies were performed in different solvent systems showing higher distribution coefficient (Kd) values. The SDS-TiP nanocomposite is active as a catalyst under visible light having optical absorption wavelength below 600 nm and the band gap obtained was 3.2 eV indicating that the material is behaving as a semiconductor. The higher photocatalytic activity of SDS-TiP is attributed due to the structure of the catalyst, optimal amount of SDS-TiP (5 g/dm3) and the initial concentration of methylene blue (MB) was found to be 20 ppm. It was observed that 90% of MB dye was removed after exposure to solar radiation for short duration. SDS-TiP can be effectively used as a highly efficient photocatalyst for the decomposition of MB dye as well for the removal of metal ions. Graphic abstract: [Figure not available: see fulltext.].