Dual application of ZnSe QDs: Lead ions detection via off-fluorescence sensing and Fe₃O₄/MWCNT/ZnSe nanocomposites for water treatment

چکیده مقاله

The advancement of nanotechnology offers effective strategies to tackle environmental issues such as water contamination by toxic heavy metals and organic dyes. In this study, ZnSe quantum dots (QDs) were utilized as a simple, rapid, and on-site off-fluorescence sensor for detecting lead ions in water. The sensor demonstrated high selectivity with a detection limit (LOD) of 3.33 nM for Pb²⁺ ions. Furthermore, Fe₃O₄/MWCNT/ZnSe nanocomposites were synthesized via a hydrothermal method. Their structural, morphological, and electrochemical properties were systematically characterized using XRD, Raman, EDS, FESEM, TEM, CV, ECSA, VSM, FT-IR, and EIS analyses. The successful formation of Fe₃O₄/MWCNT/ZnSe nanocomposites was confirmed by XRD, Raman, VSM, EDS, and FT-IR analysis. Also, FESEM and TEM analysis showed spherical growth of ZnSe and Fe₃O₄ nanoparticles on multi-walled carbon nanotubes. The synthesized Fe₃O₄/MWCNT/ZnSe nanocomposite was then applied for the removal of crystal violet dye from water. Experimental results showed that Fe₃O₄/MWCNT/ZnSe nanocomposite degraded crystal violet dyes from the media in one minute only. Overall, ZnSe QDs and Fe₃O₄/MWCNT/ZnSe nanocomposites show strong potential as fluorescence sensors for lead ion detection and as efficient catalysts for wastewater treatment. © 2025 Elsevier B.V.