ItemArticle

Eco-friendly synthesis of NiO and Ag/NiO nanoparticles: Applications in photocatalytic and antibacterial activities

Title
Eco-friendly synthesis of NiO and Ag/NiO nanoparticles: Applications in photocatalytic and antibacterial activities
Creator
Ravishankar, T.N.; Ananda, A.; Shilpa, B.M.; Adarsh, J.R.
Description
Herein, NiO and Ag/NiO NPs were produced via the solution combustion method using nickel nitrate and silver nitrate as oxidizers and Cocos nucifera water as a fuel at 450C. The study also explores their applications in photocatalytic dye degradation, H 2 production and antibacterial properties. The primary advantage of using C. nucifera water as a green fuel in the solution combustion method is that it serves a dual purpose - both as a fuel and as a solvent. This eliminates the need for additional water to create a homogeneous redox mixture of fuel and oxidant in the experimental procedure. X-ray diffraction confirmed the existence of Ag in the bunsenite form of rhombohedral structure with a simple cubic system, with particles sized at 31-44 nm. Energy-dispersive X-ray spectroscopy revealed Ni, O and Ag weight percentages of 48.2, 44.5 and 7.3%, respectively. X-ray photoelectron spectroscopy confirmed the formation of Ag in NiO nanostructure. UV-visible spectrometry showed reduced band gap energy of Ag/NiO NPs (3.03-2.87 eV) compared to the bare NiO NPs (3.21 eV), red shift of the optical response towards the visible region after doping Ag into the NiO. The 0.3 wt% Ag/NiO NPs showed the highest quantum efficiency (0.781) among the other synthesized NPs. Fourier-transform infrared spectroscopy revealed absorption bands in the range of 460-900 cm -1 stretching vibrations of Ni-O and Ag-O. Photoluminescence spectroscopy indicated that a doping concentration of 0.3 wt% Ag effectively introduces donor levels, defect levels and surface trap states within the NiO nanocrystalline structure, enhancing charge carrier separation and reducing recombination. Scanning electron microscopy revealed a voluminous, porous surface morphology characterized by numerous voids, resulting from the release of various combustible gases during the combustion process. Transmission electron microscopy images showed that most particles were spherical, irregular in size and well-distributed, with minimal aggregation with an average particle size of 25.8 nm. BET analysis of both NiO and 0.3 wt% Ag/NiO NPs exhibited type IV adsorption isotherms, indicating mesoporous structures and a clear monolayer-multilayer adsorption process, 0.3 wt% Ag/NiO NPs showed the highest surface area (170 m2 g-1) compared to the NiO (130 m2 g-1) NPs. Ag/NiO NPs has demonstrated a promising H2 evolution rate of 1212 ?mol g-1 under visible light illumination in a water/ethanol system. The trypan blue dye degradation reaches up to 98% and has moderate stability for the reusable photocatalysis process. The synthesized NPs exhibited significantly enhanced antibacterial activity against a range of bacterial strains. 2025 The Authors.
Source
Royal Society Open Science;Volume;12;Issue;2;Article No.;241733;
Date
01-01-2025
Publisher
Royal Society Publishing
Subject
Ag/NiO NPs; Cocos nucifera; dye; H 2 production; NiO NPs; photocatalysis
Coverage
Ravishankar T.N., Department of Chemistry, B.M.S. College of Engineering, Bull Temple Road, Basavanagudi, Karnataka, Bengaluru, 560019, India; Ananda A., Department of Chemistry, Dayananda Sagar Academy of Technology & Management Udayapura, Kanakapura Road, Bengaluru, 560082, India; Shilpa B.M., Department of Psychology, Christ University, Bangalore Kengeri Campus, Karnataka, Bangalore, 560074, India; Adarsh J.R., Department of Chemistry, Global Academy of Technology, RR Nagar, Karnataka, Bangalore, 560098, India
Rights
All Open Access; Gold Open Access; Green Open Access
Relation
ISSN: 20545703;
Format
online
Language
English
Type
Article

Citation

Ravishankar, T.N.; Ananda, A.; Shilpa, B.M.; Adarsh, J.R., “Eco-friendly synthesis of NiO and Ag/NiO nanoparticles: Applications in photocatalytic and antibacterial activities,” CHRIST (Deemed To Be University) Institutional Repository, accessed June 18, 2026, https://archives.christuniversity.in/items/show/22833.

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