Synthesis of phytochemical-enriched MgO nanoparticles using Sonneratia ovata leaf extract for photocatalytic activity and inactivation of bacteria

The green synthesis of magnesium oxide nanoparticles was achieved using Sonneratia ovata leaf extract. Several analytical and spectroscopic methods were used to characterise the crystallite size, structural behaviour, and optical and morphological properties. The high crystalline nature and the estimated average crystallite size of 22.8 nm after calcination at 500 °C were explained by the X-ray diffraction pattern. The aqueous extract of S. ovata and the metallic precursor both had distinctive absorption bands in the FTIR spectrum that were consistent with functional groups. The spherical form of MgO NPs was seen in the FESEM images. The purity of MgO, with Mg and O present, was confirmed by EDAX spectra and mapping. Particle size analysis revealed that the MgO NPs mediated by S. ovata had an average size and range of 18.82 nm. The green synthesis of MgO NPs was found to be a promising antimicrobial agent against pathogens such as Escherichia coli and Staphylococcus aureus and to exhibit antioxidant activity. The maximum average removal of Congo Red (CR) dye was 94.2% at low pH, and around 90% for Rhodamine B (RhB) under optimal conditions. The results demonstrated that the synthesised MgO NPs show promising potential as effective nanocatalysts for wastewater treatment, thereby advancing nanotechnology and contributing to the Sustainable Development Goals (SDGs) 6, 7, 9, and 14.