Factors Influencing TiO2-based Composites for Water Decolorization: A Systematic Review

Abstract

The widespread use of synthetic dyes and their release into aquatic environments poses significant risks to human health and ecosystems. As a process for dye removal that is environmentally benign and green, photocatalysis has gained a lot of interest. Composites made of TiO2 have demonstrated potential as photocatalytic materials for water decolorization. In this study, we used key phrase analysis, keyword co-occurrence, and bibliographic couplings to examine 131 articles from the Scopus database (2017–2023). We investigated how TiO2-based composites—including doped TiO2, mixed metal oxides and supporting substrates—could be categorized based on composition. We studied various factors, such as pH, temperature, coexisting compounds, reaction time, light intensity, and initial dye concentration. These factors were found to influence the performance and stability of TiO2-based composites in water decolorization. It was discovered that doping is a method for improving light absorption of TiO2 by reducing its bandgap. The relationships between these variables also imply that the ideal photocatalytic conditions may differ based on the particular composite, dye, and environmental conditions used. Consequently, optimizing these parameters is crucial for obtaining the best photocatalytic activity.