HPA immobilized on the functionalized Ti-MCM-41 nanochannels for photocatalytic degradation of ternary azo dye effluents

Abstract

Solid-state heteropolytungstic acid (HPA) clusters were covalently linked into amino and mercapto functionalized Ti-MCM-41 nanoporous channel by in situ synthesis processes to effectively use as a recyclable photocatalyst for degradation of ternary azo dyes consisting of methyl orange (MeOr), acid orange 10 (AO-10) and acid red 88 (AR88) before and after dying processes. The structure and morphology of as synthesized nanoporous hybrid catalyst (HPA immobilized mercapto and amino functionalized Ti-MCM41) was characterized by means of Fourier transform infrared analysis (FT-IR), Phosphorus-31 Nuclear Magnetic Resonance (31P-NMR) analysis, X-ray diffraction (XRD) analysis, N2 adsorption studies, diffused reflectance studies (DRS) and transmission electron microscope (TEM) measurements. The immobilization of HPA on functionalized Ti-MCM-41 acts as coupled semiconductor with higher specific area and superior active sites for photocatalytic degradation of ternary azo dyes. The hybrid catalyst was found to be very stable and did not lose it activity even after performing three consecutive irradiation experiments with azo dye mixtures; hence it may be reusable for further degradation of dye mixtures.