Enhanced photocatalytic performance of ZnO nanoparticles functionalized with 5-(4′-carboxyphenyl)-10,15,20-triphenylporphyrin-zinc

ZnO nanoparticles were decorated with 5-(4′-carboxyphenyl)-10,15,20-triphenyl porphyrin-zinc (ZnTPPCO2Na) and used for photocatalytic removal of Rhodamine B dye. The morphology, composition, and structure of the resulting ZnTPPCO2Na/ZnO nanocomposite were characterized by SEM, HRTEM, XRD, EDS, UV–vis, and FTIR spectroscopy. The nanocomposite exhibits spherical nanoparticles of diameter 30–100 nm with an extremely thin organic layer on the surface. The nanomaterial exhibited good photocatalytic degradation of Rhodamine B in aqueous solution, far exceeding the performance of pure ZnO nanoparticles. The thinness of the porphyrin layer aids the synergistic combination between the nanomaterials, significantly increasing the removal rate of RhB up to 99.86 % after 120 min under UV light illumination. The photocatalytic mechanism occurs at the interface between ZnTPPCO2Na, ZnO, and dye and mainly involves O2- and OH, enhancing charge separation via exciton-coupled charge transfer processes. Despite promising results, the UV-specific activity limits the usability, emphasizing the need for visible light-responsive systems for broader applications in environmental remediation.