Recyclable Sn-TiO2/polythiophene nanohybrid material for degradation of organic pollutants under visible-light irradiation

Abstract

A Sn-doped TiO2/polythiophene nanohybrid (SPNH) was synthesized by a modified sol–gel process at low temperature. The prepared catalyst was characterized by X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV−Vis) diffuse reflectance spectrophotometry (UV-DRS), and Brunauer-Emmett-Teller surface area analysis. The XRD results confirmed that polythiophene (PTh) had no effect on the crystal structure of TiO2. IR spectra and UV-DRS indicated that an interaction occurs between the interface of PTh and metal oxide in SPNH, and doped metal oxide nanoparticles were incorporated into PTh to form a core-shell structure. XPS analysis confirmed the presence of Sn4+ and respective elements of PTh and TiO2 in SPNH. SPNH displayed higher adsorption capacities for pollutants than Sn-doped TiO2 nanoparticles (STN). In addition, SPNH exhibited higher photocatalytic activity and stability than STN towards the degradation of organic pollutants nitrobenzene (NB) and malachite green (MG) under visible-light irradiation. Because of the presence of PTh on STN, there was an increase in the adsorption of NB (24%) and MG (21%) on the surface of SPNH, which led to a higher photocatalytic yield. The recyclability of the photocatalytic activity for the photocatalyst was examined by about five runs and not found any depletion or degradation of PTh under visible light irradiation. The high photocatalytic activity of SPNH makes it an attractive candidate as a photocatalyst for industrial water purification.