Dual-role deep eutectic solvent-assisted electrosynthesis of TiO2/KCC-1 for enhanced visible-light photocatalytic desulfurization

In this work, an innovative TiO2-based photocatalyst was synthesized via a DES-assisted electrosynthesis method, where the DES serves a dual role: acting as both a green electrolyte and a structural stabilizer. This composite, comprising fine TiO2 on dendritic fibrous nanosilica, exhibited significantly improved physicochemical properties due to the formation of strong Si–O–Ti interfacial bonds, uniform TiO2 distribution, and enhanced morphological integrity. Detailed characterizations (XRD, FTIR, TEM, XPS) validated both the structural evolution and successful loading of TiO2 onto the KCC-1 support. Visible light was used to evaluate the photocatalytic performance in the degradation of dibenzothiophene (DBT) which is a model refractory sulfur compound. The optimum 15 wt% TiO2/KCC-1 catalyst achieved a remarkable 97.44% DBT degradation within 180 min, outperforming pristine TiO2 and previously reported systems. More importantly, this catalyst showed excellent reusability for maintaining more than 92% of its initial activity after five cycles with very little structural deterioration. Employing DES greatly enhanced charge carrier separation, active site exposure, and structural stability, which are crucial for visible-light photocatalysis. This work proposes an easy, green method for synthesizing advanced photocatalysts, offering a promising solution for ultra-deep desulfurization of fuels in line with global efforts for clean energy and environmental remediation.