Self-assembly of porphyrin nanofibers on CeO 2 nanoparticles: an enhanced photocatalyst for organic pollutant degradation under visible light irradiation

This study investigates the synthesis and photocatalytic performance of CeO ₂ /porphyrin nanocomposites, created by self-assembling porphyrin monomers onto CeO ₂ nanoparticles, which were green-synthesized using Cleistocalyx operculatus leaf extract. The resulting CeO ₂ /porphyrin composite showed enhanced photocatalytic efficiency for degrading organic pollutants, such as methylene blue and rhodamine B, compared to individual CeO ₂ nanoparticles and free porphyrin aggregates. CeO ₂ nanoparticles were characterized by SEM, XRD, FTIR, EDX, and UV-Vis, confirming successful synthesis and their crystalline integrity. The porphyrin TCPP (Tetrakis(4-carboxyphenyl)porphyrin) was integrated via a reprecipitation method, and SEM and XRD analysis verified the uniform incorporation of TCPP onto CeO ₂ nanoparticles, preserving the nanofiber morphology and a crystalline structure with an average size of 9 nm. The CeO ₂ /TCPP composite exhibited extended visible light absorption, as shown in UV-Vis diffuse reflectance spectra, indicating its potential for photocatalytic applications under visible light. Photocatalytic tests under simulated sunlight demonstrated a significant improvement in performance, with a 95.9% degradation of Rhodamine B after 120 minutes, particularly at a CeO ₂ :TCPP ratio of 10:1. This research highlights the effective synergy between CeO ₂ and porphyrin materials, providing a novel approach for developing efficient, green-synthesized nanocomposites for environmental remediation under visible light, marking a significant contribution to photocatalytic technology.