Sandwich composites of bismuth sulfide nanoparticles decorated with cobalt ferrite oxide for waste water treatment

To detect cadmium (Cd2+) ions, electrochemical and calorimetric studies have been performed due to their high sensitivity and selectivity. Heterogeneous photocatalysts have been used to degrade and decolorize azo dyes because they are adaptable, cause less secondary pollution, and are cost-effective. In this study, synthesized Bi2S3 nanoparticles adorned on CoFe2O4 (BiSNPs@CFO) substrates by using chemical methods. The primary source of Cd2+ ions in digested detergent samples was detected and coded as samples A, B, and C. Laundry wastewater was denoted as sample D. Both photoluminescence spectroscopy (PL) and cyclic voltammetry techniques (CV) were employed to detect the presence of cadmium ion in the selected samples. Pollution assessment risk index values indicated that samples B and C contributed to Cd2+ ions pollution more compared with sample A. The Igeo (geo-accumulation) values were 4.08 (sample B), 3 (sample C), and 13.5 (sample D), which indicated a high pollution level. Then, the methylene blue (MB) dye was periodically degraded at a fixed concentration and pH, and the efficiency reached 83%, with the apparent rate constant of 0.0106/min with a high R2 value of approximately 0.9015. In this study, the two pathogens were isolated from laundry wastewater, namely, Aspergillus sp. and Trichoderma sp, and their growth and biomass production were examined. The antifungal activity of BiSNPs@CFO composites was studied using the standard fluconazole. The nanocomposites can be used as a probe to detect the presence of Cd2+ ions and degrade azo dyes and Aspergillus sp. and Trichoderma sp. predominantly grown in laundry wastewater. [Display omitted] •BiSNPs@CFO is a heterojunction catalyst effectively engineered using simple chemical methods.•The surface morphology of the as-prepared composites plays a vital role in the detection and degradation process.•The prepared composites are used as a probe to Turn On the sensor to Cd2+ ions in the selected chemical samples•The BiSNPs@CFO substrate is used to hinder the degradation of MB dye molecules under visible light irradiation.•The application is extended to antifungal activity against Aspergillus sp. and Trichoderma sp.