ZnO-embedded cellulose acetate butyrate/plant extract membranes for catalytic reduction of organic pollutants: role of anthocyanins as structural agents, catalytic promoters, and by-product indicators.

This study presents a novel bio-based catalytic membrane for efficient water remediation, combining a cellulose acetate butyrate (CAB) matrix with ZnO nanoparticles and anthocyanin extract (ACy). The integration of ACy into the hybrid membrane not only enhances structural and mechanical stability but also plays a critical role in catalytic performance. The CAB/ACy/ZnO membrane fabricated using the solution casting technique exhibits improved elasticity and hardness due to synergistic interactions between the polymer, inorganic nanoparticles, and bioactive ACy molecules. The catalytic activity was investigated for the reduction of azo dye Direct Red 16 and other persistent organic pollutants, using NaBH4 as a reducing agent. The hybrid membrane demonstrated rapid and highly efficient dye degradation, achieving up to 98.5% removal within 8 min. The incorporation of ACy promoted the formation of a porous structure within the membrane, increasing the accessible surface area and the number of active catalytic sites. The membrane also exhibited excellent recyclability and chemical stability over multiple cycles and under a range of mineral salt samples. This work highlights the multifunctional role of ACy in enhancing catalytic efficiency, facilitating real-time monitoring, and supporting sustainable water treatment, providing a promising strategy for the degradation of organic pollutants in industrial effluents.