A comparative analysis of photocatalytic applications using poly[(vanillin-co-pyrrole)]/ZnO and TiO2-based semiconductor under natural sunlight irradiation

This study presents an experimental investigation with a comparative analysis on the photocatalytic activity of two composites, namely poly(vanillin-co-pyrrole)/ZnO and poly(vanillin-co-pyrrole)/TiO2, for the degradation of methylene blue (MB) dye under simulated solar irradiation. Conductive polymers, specifically poly(vanillin-co-pyrrole) (PPHMB) and its derivatives, were employed as photosensitizers to enhance the photocatalytic activity of ZnO and TiO2 under solar irradiation. PPHMB was synthesized using the cationic polycondensation method, while the PPHMB/ZnO and PPHMB/TiO2 composites were prepared through the co-precipitation method. The prepared composites exhibited superior photocatalytic activity compared to bare ZnO and TiO2 under solar irradiation for the degradation of MB dye. Extensive characterization techniques, including Fourier-transform infrared, x-ray diffraction, thermogravimetric analysis, and optical analysis, were employed to investigate the properties of the composites. Various influential operational parameters such as initial dye concentration, irradiation time, and the dosage of PPHMB/ZnO and PPHMB/TiO2 composites were systematically studied to evaluate their effects on photocatalytic degradation. The optical density of dye degradation was quantified using a UV-Visible spectrophotometer, while the repeatability of the photocatalytic activity was rigorously assessed.