Natural gum-based nanocomposite materials for the photocatalytic degradation of dye pollutants in wastewater: a review of recent advances, technology readiness levels, environmental threats, innovative pathways, and AI integration.

Photocatalytic degradation-oriented technology remains at the forefront of advanced oxidation processes for the removal of water pollutants like dyes. In the search for a cheap, green, eco-sustainable photocatalysts, natural gum-based nanomaterials (NGBNs) have garnered considerable attention. Thus, this review aims to present a critical analysis of the latest research findings and advances in the application of NGBNs for the photocatalytic degradation of dye pollutants in simulated wastewater. Notably, the study findings revealed that various NGBNs show a consistent trend of excellent degradation efficiency at a residence time of 1-760 minutes, a dose of 0.5-1000 mg, and a light intensity of 8-500 W. This remarkable efficiency was due to a narrow band gap and an abundance of oxygenated functional groups imparted to NGBNs by natural gums. Reusability and photostability analyses showed that NGBNs can be reused 3-7 times while still delivering ≥85% efficiency without seriously compromising the architectural morphology. Besides evaluating the efficiency of NGBNs for dye degradation, this review presents the ecotoxicity and ecological structure-activity relationships and identifies the strengths, weaknesses, opportunities, and threats that can serve as future directions to advance the research beyond grade 4 of the technology readiness level towards actual implementation in wastewater treatment systems.