Green Synthesis of SnO₂ Nanomaterials: Photocatalytic Degradation of Methylene Blue and DFT-Based Investigation of Nonlinear Optical Properties

Muhammad Amir Abbas; Jamaluddin Mahar; Nasir Ali; Muhammad Junaid; Muhammad Shahid Rasool

doi:10.5281/zenodo.19693725

Authors

Muhammad Amir Abbas Institute of Chemistry, the Islamia University of Bahawalpur, Bahawalpur, Pakistan Author
Jamaluddin Mahar Department of Chemistry, Quaid-E-Azam University Islamabad, Islamabad, Pakistan Author
Nasir Ali Departments of Physics, Government Degree College Saleh Pat, Sukkur, Pakistan Author
Muhammad Junaid Institute of Chemistry, the Islamia University of Bahawalpur, Bahawalpur, Pakistan Author
Muhammad Shahid Rasool Departments of Chemistry, University of Karachi, Karachi, Pakistan Author

DOI:

https://doi.org/10.5281/zenodo.19693725

Keywords:

SnO₂ nanoparticles; green synthesis; Moringa oleifera; photocatalytic degradation; NLO; DFT

Abstract

Environmental pollution by synthetic dyes and industrial effluent is a serious threat to ecosystems and human health; therefore, the development of effective and sustainable remediation technologies is an urgent priority. This work reports the successful synthesis of SnO₂ nanomaterials through a green synthesizing route using an aqueous extract of Moringa oleifera leaves as a reducing and stabilizing agent. Various structural and morphological studies were performed to confirm the formation of highly crystalline cassiterite SnO₂ with mesoporous, quasi-spherical nanoparticles of high specific surface area. The optical studies indicated a wide bandgap and strong light absorption, suitable for photocatalytic applications. Green-synthesized SnO₂ nanoparticles demonstrated excellent photocatalytic performance with 96% degradation of methylene blue upon visible-light irradiation at a high pseudo-first-order rate constant k = 0.4661 min⁻¹, along with good thermal stability and reusability. DFT calculations were conducted to illustrate the degradation mechanism. The decrease in the HOMO-LUMO energy gap in the case of SnO₂@MB system reflected an increased possibility of charge transfer. Global quantum reactivity descriptors indicated an increased softness and electrophilicity while molecular electrostatic potential, NCI-RDG, and QTAIM analyses demonstrated strong interfacial interactions with partial covalent character. The perfect agreement between experimental and computational results underlines the potentials of green synthesized SnO₂ nanomaterials for efficient dye degradation and advanced optoelectronic applications.

Author Biographies

Muhammad Amir Abbas, Institute of Chemistry, the Islamia University of Bahawalpur, Bahawalpur, Pakistan

Institute of Chemistry, the Islamia University of Bahawalpur, Bahawalpur, Pakistan
Jamaluddin Mahar, Department of Chemistry, Quaid-E-Azam University Islamabad, Islamabad, Pakistan

Department of Chemistry, Quaid-E-Azam University Islamabad, Islamabad, Pakistan
Nasir Ali, Departments of Physics, Government Degree College Saleh Pat, Sukkur, Pakistan

Departments of Physics, Government Degree College Saleh Pat, Sukkur, Pakistan
Muhammad Junaid, Institute of Chemistry, the Islamia University of Bahawalpur, Bahawalpur, Pakistan

Institute of Chemistry, the Islamia University of Bahawalpur, Bahawalpur, Pakistan
Muhammad Shahid Rasool, Departments of Chemistry, University of Karachi, Karachi, Pakistan

Departments of Chemistry, University of Karachi, Karachi, Pakistan

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