AUTHOR=Farooq Rehana , Singh Manjeet , Singh Jasminder , Mehta Akansha 

TITLE=Visible-light-driven photocatalytic degradation of toxic insecticide thiamethoxam using Ni-doped PbS nanoparticles under visible light irradiation

JOURNAL=Frontiers in Materials

VOLUME=Volume 12 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2025.1677416

DOI=10.3389/fmats.2025.1677416

ISSN=2296-8016

ABSTRACT=The widespread use of the toxic insecticide Thiamethoxam (TMX) poses significant risks to environmental and human health, necessitating effective remediation methods. This study reports the successful synthesis of novel Nickel-doped Lead Sulfide (Ni-PbS) nanoparticles via a straightforward co-precipitation approach for the visible-light-driven photocatalytic degradation of TMX. Structural analysis confirmed that the Ni-PbS nanoparticles crystallize in a face-centred cubic structure. Morphological examination revealed a flower-like architecture composed of nanosheets. Optical studies showed a narrowed band gap of 2.2 eV, confirming visible-light responsiveness. X-ray photoelectron spectroscopy (XPS) further verified the presence of Pb2+, S2-, and the successful incorporation of Ni2+ into the PbS lattice. The Ni-PbS catalyst demonstrated significantly enhanced photocatalytic activity, achieving 78.93% TMX degradation within 210 min with a rate constant of 0.02225 min−1. Optimal performance was observed at pH 3 and a catalyst loading of 0.5 g/L. The catalyst also exhibited excellent stability and reusability over five consecutive cycles. Scavenger studies revealed that valence band holes (h+) and hydroxyl radicals (•OH) were the dominant reactive species driving the degradation. Overall, this work highlights Ni-PbS as a robust and efficient photocatalyst for the remediation of water contaminated with neonicotinoid insecticides.