Controlled Doping as a Viable Strategy for Developing Energy Efficient Photocatalyst for Degradation of Multiple Aquatic Pollutants

Abstract

Among all the known conventional photocatalysts, TiO2 has most popularly been used in many industrial applications for the remediation of multiple environmental pollutants via an advanced oxidation process. However, its wide band gap hinders its application as it poorly absorbs visible light. Various strategies have been made to reduce its band gap for utilizing the solar spectrum absorbance in the visible range. For obtaining an effective energy-efficient photocatalytic system, doping with metallic and non-metallic components could be a viable strategy that may also be associated with other scientific benefits. In our present study, multiple metals and non-metals as dopants were used to prepare novel titania-based nano photocatalysts, and their photoexcitation nature and degradation efficacy under solar irradiation were studied. The aim of the study was primarily to understand the effect of the type of dopants on the effectiveness of titania-based photocatalysts for the degradation of multiple pollutants such as azo dyes, phenolic compounds etc. The study was also tested for finding the best dopant and their optimum range of doping for maximum photocatalytic degradation of multiple aquatic pollutants using titanium under sunlight. Confirmation of pollutant degradation was achieved through FTIR analysis, absorption spectroscopy, COD analysis, TOC analysis, and scavenging tests. Various parameters such as the atomic size of the dopant, the dopant concentration, particle size of the photocatalyst, band gap, recombination rate, degradation rate, sunlight exposure time, and photocatalyst dosage were used for designing an optimization model for finding the best combination of a titania-based photocatalyst system. Our study demonstrated that a straightforward approach can be designed for synthesizing metal and non-metal doped nano Titanium dioxide photocatalyst, thus offering a better understanding of the functionalized catalyst to produce cost-effective and energy-efficient solutions for the degradation of multiple aquatic pollutants and thus holding a great promise for environmental remediation.