Tailoring ZnS nanostructures through precipitation-cum-hydrothermal synthesis for enhanced wastewater purification and antibacterial treatment

• Published in: Environmental research Vol. 259; p. 119534
• Main Authors: Kaur, Harpreet, Kumar, Sanjeev, Kumar, Parul, Ghfar, Ayman A., Bouzid, Gassoumi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 15.10.2024
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibacterial activity; antibacterial properties; Chemical Precipitation; crystal structure; crystallites; Degradation; electron microscopy; encapsulation; Hydrothermal method; irradiation; methylene blue; Methylene blue dye; nanoparticles; Nanospheres; Nanostructures - chemistry; photocatalysis; polyvinylpyrrolidone; Povidone - chemistry; PVP-ZnS; Sulfides - chemistry; surface area; transmission electron microscopes; ultraviolet-visible spectroscopy; wastewater; Wastewater - chemistry; Water Purification - methods; X-ray diffraction; Zinc Compounds - chemistry; zinc sulfide; Degradation; Antibacterial activity; Hydrothermal method; Nanospheres; Methylene blue dye; PVP-ZnS
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2024.119534

This study presents a novel blend of synthesis techniques for shape-controlled ZnS nanoparticles. Zinc sulfide (ZnS) nanoparticles with distinct morphologies cauliflower-like microstructures (∼4.5 μm) and uniform nanospheres (200–700 nm) were synthesized through an innovative blend of precipitation and hydrothermal techniques. Capping with polyvinylpyrrolidone (PVP) significantly decreased crystallite size (3.93 nm–2.36 nm), modulated the band gap (3.57 eV–3.71 eV), and dramatically influenced morphology, highlighting the novelty of shape-controlled synthesis and its impact on optoelectronic and functional properties. X-ray diffraction confirmed crystallinity and revealed the size-controlling influence of PVP. UV–vis spectroscopy suggested potential tuning of optical properties due to band gap widening upon PVP capping. Field-emission scanning electron microscopy (FESEM) unveiled distinct morphologies: cauliflower-like microstructures for ZnS and uniform nanospheres (200–700 nm) for PVP-ZnS. Both structures were composed of smaller spherical nanoparticles, demonstrating the role of PVP in promoting controlled growth and preventing agglomeration. High-resolution transmission electron microscope (HRTEM) images depicted that the majority of nanoparticles maintain a spherical shape, though slight deviations from perfect sphericity can be discerned. Fourier-transform infrared (FTIR) spectroscopy confirmed that successful PVP encapsulation is crucial for shaping nanospheres and minimizing aggregation through steric hindrance. Photocatalytic activity evaluation using methylene blue (MB) dye degradation revealed significantly faster degradation by PVP-ZnS under ultraviolet (UV) irradiation (within 60 min as compared to 120 min for ZnS), showcasing its superior performance. This improvement can be attributed to the smaller size, higher surface area, and potentially optimized band gap of PVP-ZnS. Additionally, PVP-ZnS exhibited promising antibacterial activity against S. aureus and P. aeruginosa, with increased activity at higher nanoparticle concentrations. •A novel synthesis approach for the formation of ZnS nanoparticles with controlled shapes.•Development of cauliflower-like ZnS and PVP capped ZnS nanospheres.•Evaluation of the antibacterial and photocatalytic efficiency of ZnS and PVP capped ZnS.