Application of Structured Sol-Gel Nb₂O₅ Catalyst in Photocatalytic Continuous Process Prototype for Ibuprofen Degradation

Three distinct sol-gel synthesis methodologies were employed to fabricate niobium catalysts supported on stainless steel meshes via the dip-coating technique, with the objective of their utilization in layered configurations for water purification applications. The structured catalysts were subjected to calcination at three varying temperatures: no calcination, calcination at 823 K, and calcination at 1173 K. Ibuprofen, selected as the model pollutant due to its emerging contaminant profile, was utilized for evaluation. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) images, in conjunction with adhesion assessments, elucidated that thermally treated catalysts exhibited nearly 80% retention of Nb₂O₅ nanoparticles adhered uniformly to the support surface. In batch reactor experiments, the catalyst derived from the NbCl₅ precursor and polyacrylonitrile (PAN) exhibited the most promising performance, achieving a 90% degradation of the contaminant within a 120 min timeframe. This catalyst, exhibiting superior efficacy, was subsequently employed in tests utilizing photocatalytic bench reactors, where it demonstrated analogous performance to that observed in the batch reactor setup. Upon upscaling to a high-capacity photocatalytic prototype, the degradation efficiency was sustained above that observed in photolytic testing, even after four utilization cycles.