A systematic evaluation of physiochemical properties and solar-driven photocatalytic activity of nanosized Mn doped CdS on Methylene Blue dye

Abstract

Manganese ions were incorporated into CdS nanosystem using wet chemical protocol at different pH values namely 9.0,10.0 and 11.0 and the same were used for photocatalytic degradation of Methylene blue (MB) dye via adsorption phenomena. Several standard analytical techniques were employed to analyse the synthesized nanocompounds: XRD, scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy, and vibrating-sample magnetometry. The structural analysis revealed the presence of primary cubic zinc blende structure with secondary phases. The morphological studies confirmed the formation of nanostructured particles for all pH values, amongst, pH 10.0 grown particles were showing less agglomeration and better particle stabilization. The TEM analysis confirmed the particle size of 23 nm. The absorption edge and its position shown by UV-Vis absorption analysis exhibited a broad envelope and strong blue shift due to an uneven size distribution and nanodimensional state formation of particles, respectively. The elevation to superparamagnetic state from native diamagnetic state of CdS due to Mn ions incorporation was confirmed by VSM studies. The dual phase composition significantly enhanced the photocatalytic efficiency by improving charge separation and extending light absorption. The MnS phase effectively trapped electrons, reduced recombination rates and facilitated the generation of reactive species. The photocatalytic degradation of methylene blue dye was more efficient (88.87 %) under direct sunlight exposure. Additionally, the enhanced surface properties and adsorption characteristics, as confirmed by the Freundlich isotherm and intraparticle diffusion model, contributed to the superior degradation performance.