Environmental risks of textile dyes and photocatalytic materials for sustainable treatment: current status and future directions

This review highlights the critical issue of water pollution caused by synthetic dyes and dissolved organic matter, focusing on their persistence, complex chemistry, and adverse effects on human health and aquatic ecosystems. It examines their sources, environmental fate, and ecological impacts, including disruptions to microbial communities and marine biodiversity. Emphasis is placed on advanced photocatalytic remediation strategies, especially those employing metal oxide-based nanomaterials. The review outlines key factors that influence photocatalyst performance, including band gap tuning, surface area, morphology, charge separation efficiency, and light absorption. Strategies like doping, heterojunction formation, and nanocomposite design are discussed to enhance photocatalytic efficiency. The novelty of this work lies in its integrated discussion on the toxicity of dyes, dissolved organics, and metal oxide-based heterostructures, providing a clear synthesis of current advances. This review aims to support future research and the development of sustainable solutions for dye-contaminated wastewater treatment.