Biosynthesis and Characterization of Mn3O4 Nanoparticles Using Bixa orellana and Nerium oleander Leaf Extracts at Low Temperature and Neutral pH

Valle-Rivera E.; Jáuregui-Rosas S.R.; Avila-Concepción S.P.R.; Samanamud-Moreno F.V.; Zavaleta-Espejo G.G.; Huaman-Quispe J.; Gavidia-Sare S.; Saldaña-Jiménez J.A. · Crystals (2025) · DOI: 10.3390/cryst15030226

Resumen

Mn3O4 nanoparticles have been synthesized using alcoholic extracts, at pH = 7 and low temperature (60 °C), from different masses (1.00, 3.00, 5.00, and 7.00 g) of fresh leaves from Nerium oleander and Bixa orellana, without additional heat treatment. Appropriate techniques were used to identify the secondary metabolites of the extracts and evaluate the structural, optical, and chemical properties of the nanoparticles. The XRD results confirmed the formation of Mn3O4 nanoparticles with crystallite size in the 5−8 nm range, with more notable effects on the crystallinity of the nanoparticles obtained with B. orellana extracts. The greatest effect on the bandgap was observed in nanoparticles synthesized with N. oleander extracts. Raman spectra confirmed phonon confinement, and in the PL spectra, emission bands associated with structural defects, such as oxygen vacancies, were observed. In FTIR spectra, the main bands of Mn3O4 were identified, whose intensity decreased as the concentration of extract and other bands associated with functional groups of the extract increased. TEM images showed nanoparticles were spherical with 7.81 nm (N1) and 7.94 nm (B1) average diameters. The extract from N. oleander leaves was more appropriate than that from B. orellana for the synthesis of Mn3O4 nanoparticles under the conditions used.

Instituciones: Universidad Nacional de Trujillo