ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Thespesia populnea leaf extract-based biogenic synthesis of Ag-decorated cobalt ferrite nanocomposite: antibacterial and catalytic insights

Swati Gubbala, Gayathri Bindu Kurup, Prashanth Goud Banda, and Raghasudha Mucherla

Department of Chemistry, National Institute of Technology Warangal, Warangal, India

E-mail: sg22cyr1p01@student.nitw.ac.in

Received: 16 January 2026  Accepted: 10 April 2026

Abstract:

A green hydrothermal route was employed to synthesize silver-decorated cobalt ferrite (Ag–CoFe₂O₄) nanoparticles (NPs) using Thespesia populnea leaf extract (TPE) as a natural bio-reductant and stabilizing agent, while alkaline conditions maintained by NaOH facilitate controlled ferrite nucleation and phase formation. This tropical Malvaceae species served as an eco-friendly and cost-effective medium for green synthesis. The resulting Ag–CoFe₂O₄ NPs were comprehensively characterized using FTIR, XRD, FESEM, EDX, XPS, HR-TEM, UV–visible spectroscopy, and VSM, confirming their structural integrity, morphology, surface chemistry, and magnetic properties. Catalytic studies demonstrated their high efficiency in the reduction of 4-nitrophenol (4-NP) at room temperature in the presence of NaBH₄. Further showcasing their multifunctional behavior, the NPs displayed excellent visible-light-driven photocatalytic activity, achieving 87% degradation of crystal violet (CV) dye within 60 min in the presence of H₂O₂, enabled by enhanced light absorption, efficient charge separation, and hydroxyl-radical generation. The NPs exhibited preliminary concentration-dependent antibacterial activity against multiple pathogenic strains. Owing to their strong magnetic response, the NPs could be readily separated using an external magnet and reused with minimal loss of activity. Overall, the Ag–CoFe₂O₄ NPs demonstrate promising multifunctionality as recyclable antibacterial, catalytic, and photocatalytic agents for environmental remediation and biomedical applications.

Graphical abstract

Keywords: Silver-decorated cobalt ferrite; Thespesia populnea; Hydrothermal; Antibacterial; Catalytic reduction; Photocatalytic degradation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04905-3

Chemical Papers 80 (8) 8675–8695 (2026)