Molecular energy transfer: utilizing biogenically-synthesized ZnMn2O4 nanoparticles from Arachis hypogaea seeds for photoluminescence, adsorption, and photocatalytic applications

Abstract

The green synthesis of nanoparticles (NPs) has emerged as a sustainable alternative to conventional chemical approaches, primarily due to the use of phytochemicals as reducing and stabilizing agents. In the present study, bimetallic ZnMn₂O₄ nanoparticles were synthesized via a green combustion method employing Arachis hypogaea (peanut) seed powder as a natural fuel source. The synthesized ZnMn₂O₄ NPs were systematically characterized using XRD, FTIR, SEM, BET, UV-Vis, and PL spectroscopy to elucidate their structural, morphological, and optical properties. Distinct bluish-green fluorescence was observed under short-wave UV irradiation (254 nm), enabling their application in latent fingerprint visualization. The multifunctional performance of the ZnMn₂O₄ NPs was further demonstrated in environmental applications. The materials exhibited enhanced adsorption (63% ± 0.2%) and photocatalytic degradation (79% ± 0.3%) efficiencies against Methylene Blue (MB) dye under UV irradiation, with results statistically significant (p < 0.05). In addition, the NPs effectively reduced toxic Cr(VI) ions in aqueous media, highlighting their potential as efficient detoxification agents. Overall, this work demonstrates a novel, green synthesis route for ZnMn₂O₄ nanoparticles that uniquely integrates environmental remediation and forensic applications. The dual functionality addressing both pollutant degradation/detoxification and forensic fingerprint visualization positions this study as a rare and innovative contribution to the field of nanotechnology.