Spiropyran Functionalized TiO2-Based Hybrid Nanomaterials for Enhanced Photocatalytic Response Under Simulated Solar Conditions

Abstract Carbamazepine (CBZ) is a persistent emerging pollutant that presents a major risk to aquatic ecosystems and public safety. In this work TiO 2 APTES-functionalized spiropyran-based nanoparticles as an efficient catalyst for the removal of CBZ from water were designed. Detailed structural, morphological, optical, chemical and surface area investigations demonstrate the successful functionalization of the material. The highest photocatalytic activity was achieved at an optimal catalyst loading of 0.75 g/L under simulated solar light, following a pseudo-first-order kinetic model with a rate constant of 0.0313 min⁻ 1 (R 2 = 0.999). Radical scavenging tests demonstrate that HO⋅, O 2 ⋅⁻ radicals and h + have a major contribution to the CBZ degradation mechanism. Overall, based on the results, the catalyst containing the organic photosensitizer appears to be a feasible and promising material for the efficient removal of persistent pollutants in water.