Application of Mg-doped TiO2 coated buoyant clay hollow-spheres for photodegradation of organic pollutants in wastewater

Abstract

The present work attempt to demonstrate a sustainable wastewater treatment process which is cost-effective, durable and employs light-weight functional material. Specifically, the study reveals the preparation of photocatalyst (Mg@TiO2) decorated on natural floatable spheres for photo-oxidation of organic pollutants under sunlight irradiation. About 10–15 mm diameter spheres were prepared mainly using clay and activated carbon. Mg@TiO2 photocatalytic particles were decorated on the surface of clay spheres and sintered at 550 °C temperature. The as-prepared photocatalyst decorated spheres were characterized by powder XRD, FTIR, SEM-EDX, and BET. The characterization results indicated well crystalline structures, adequate porosity and enough surface area, high stability and high photocatalytic activity which apparently enhanced photocatalysis. Treatment efficiency in terms of Chemical oxygen Demand (COD) was evaluated under different light sources using real-time industrial wastewater samples. The results showed about 80–90% removal of organic pollutants in textile and pharmaceutical industrial effluents within 24 h under sunlight. In addition, the recovery, recyclability, and reproducibility of the proposed photocatalyst were appreciable. The catalyst remained active and exhibited fair degradation efficiency up to 10–15 cycles. The spherical shape and buoyant nature influenced treatment efficiency by continuous spinning that made the illumination of decorated photocatalysts to photon and thereby inducing the intimate contact between pollutants and catalyst.