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

An enhanced solar driven photodegradation of methylene blue and antibacterial activity by Ag doped CeO₂ nanocatalyst

Rekha Pachaiappan, Sarojini Devi Nagesh, Ashish Kumar Nayak, María Janet Arenas-Herrera, Balu Vinayagamurthi, and Lorena Cornejo-Ponce

Energy Center, FCFM, University of Chile, Santiago, Chile

E-mail: rekha.ap@gmail.com

Received: 6 August 2025  Accepted: 17 November 2025

Abstract:

Water contamination poses a significant environmental challenge worldwide, especially in developing nations where industrial effluents and urbanization have led to severe pollution of water resources. In this study, cerium oxide (CeO₂) and silver-doped cerium oxide (CeO₂/Ag) nanocomposites were synthesized via a facile co-precipitation method using sodium hydroxide as the reducing and precipitating agent. The structural, optical, and morphological characteristics of the materials were analyzed using XRD, FT-IR, Raman spectroscopy, UV–Vis DRS, SEM–EDX, and HR-TEM. The Ag doping effectively reduced the band gap from 2.79 eV (CeO₂) to 2.43 eV, enhancing visible-light absorption and charge separation. Under solar irradiation, the CeO₂/Ag nanocomposite achieved ~ 84% degradation of methylene blue within 70 min, outperforming pristine CeO₂. Additionally, the nanocomposite exhibited strong antibacterial activity against both Gram-positive and Gram-negative bacterial strains, confirming its multifunctional potential for wastewater treatment. The synergistic effect of Ag incorporation improved photocatalytic efficiency and antimicrobial activity, making CeO₂/Ag a promising candidate for sustainable environmental remediation applications.

Keywords: Cerium oxide nanoparticles; Silver doping; Photocatalyst; Methylene blue dye; Solar light; Antibacterial activity

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04528-0

Chemical Papers 80 (3) 2509–2528 (2026)