Influence of various transition metals incorporated into tellurium used as antimicrobial agent and textile dye degrader

Abstract

Textile dye industry is known to release large amounts of undesirable effluents into industrial wastewater resulting in severe contamination. In this study, novel nanostructured materials were synthesized to treat such polluted water. Transition metals (e.g., vanadium—V, niobium—Nb, and tantalum—Ta) were incorporated individually into tellurium (Te) by adopting the solid-state technique. The compounds were synthesized with fixed dopant-to-host stoichiometric ratios (V:Te, Nb:Te, Ta:Te) while various characterization techniques were used to compare the characteristics of the synthesized products. Specifically, dye aqueous solution degraded with NaBH4 in the presence of tellurites of transition metal oxides acting as catalyst was studied. XRD analysis confirmed the formation of orthorhombic phase compounds in V and Ta and monoclinic compounds within Nb. Full-width at half-maximum (FWHM) data were extracted from the most intense peak in the XRD spectrum to measure the crystallite size using the Debye–Scherrer method. FESEM was used to investigate the surface morphology of the prepared compounds, which showed agglomerated particles that possessed an irregular shape. HR-TEM was employed to gain a detailed insight into the material’s crystal structure. Optical properties, functional group and chemical composition were recorded using UV–Vis, FTIR spectroscopy and EDS analysis, respectively. Raman spectroscopy was carried out to confirm the stretching vibrations and modes of the synthesized products. Thermal stability of the compounds was confirmed at high temperature with DSC/TGA. Moreover, the antimicrobial activity of these binary systems was tested against Escherichia coli (gram-ive) and Staphylococcus aureus (gram + ive) bacterial strains. It was observed that bactericidal potential was the highest at maximum concentrations of the dopant.