Sustainable remediation of dye pollutants using ash-based photocatalytic nanocomposites: A Comprehensive Review

Rapid industrialization and human activities have resulted in severe issues with organic pollutants, particularly dyes, that increase challenges in the management of wastewater. This review focuses on the sustainability and cost-effectiveness of ash-based photocatalytic nanocomposites in the removal of dyes from wastewater. Ash is the most abundant by-product derived from industrial and agricultural practices. Due to its remarkable adsorption capacity and interesting physicochemical properties, ash has emerged as one of the promising support materials for photocatalysts. The nanocomposites show enhanced degradation efficiency for various dyes by exploiting the synergistic effects of ash's adsorption capabilities and the photocatalytic activity of semiconductor materials. This review discusses synthesis methods, characterization techniques, and photocatalytic performance of ash-based nanocomposites in detail and discusses the challenges associated with stability, reusability, and practical implementation in industrial applications. Highlighting the "waste to wealth" strategy, the review underscores the dual benefits of mitigating environmental issues associated with ash disposal and advancing sustainable wastewater treatment solutions. Future research directions are proposed to optimize performance and scalability.