Sustainable fabrication of PVAc-coated Nb–ZnO nanocomposites using <i>Aegle marmelos</i> L. extract for enhanced surface activity towards photocatalytic degradation of bisphenol A and bromothymol blue

for the corresponding PVAc-Nb/ZnO NCs. The photocatalytic efficiencies of all the synthesized materials were evaluated for the degradation of BPA and BTB under UV irradiation (9 W Hg lamp). The PVAc-Nb/ZnO NCs achieved remarkable degradation efficiencies, exceeding 92% for BPA and 90% for BTB within 50 minutes. Key operational parameters-including catalyst dosage, pollutant concentration, and irradiation time-were systematically optimized. The degradation kinetics for both pollutants followed a pseudo-first-order model. To elucidate the plausible degradation mechanism and identify intermediate species, radical-quenching experiments and LC-MS analyses were also conducted. Importantly, recyclability studies demonstrated superior structural integrity and catalytic stability of the PVAc-coated samples across six to eight cycles for BPA and seven to nine cycles for BTB. In a nutshell, the PVAc-Nb/ZnO NCs exhibit significantly enhanced photocatalytic performance, making them promising candidates for efficient removal of organic pollutants from contaminated water.