A series of MgO nanoparticles were prepared by first precipitating and isolating Mg(OH) 2 nanoparticles from Mg(NO 3) 2 at three different temperatures using NaOH followed by their thermal decomposition also at three temperature settings. The effects of temperature at which precipitation and thermal decomposition of the hydroxide occurred were studied to assess their influence on nanoparticle size and surface area. The synthesised nanoparticles were characterized using a suite of techniques including Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscope (SEM) analysis. The average diameter range of MgO nanoparticles ranged between 15 and 35 nm, while for the precursor Mg(OH) 2 it varied between 28 and 45 nm. The nanoparticle surface area obtained from BET studies was found in all cases to increase from 77 to 106.4 m 2 /g with increasing temperature of precipitation. Antibacterial activities of the prepared Mg(OH) 2 and MgO nanoparticles were evaluated against the Gram-negative bacteria, Escherichia coli, and the Gram-positive bacteria, Staphylococcus aureus, using agar diffusion method. A correlation between surface area and antibacterial activity supported the mechanism of bacterial inactivation as the generation of reactive species. The Mg(OH) 2 and MgO nanoparticles both exhibited pronounced bactericidal activity towards the Gram positive bacteria than Gram negative bacteria as indicated by the extend of the zone of inhibition around the nanoparticle.
The increasing food demand owing to aggressive population growth, accompanied by climate change-related challenges necessitates new, eco-friendly strategies for sustainable agriculture. Traditional inorganic fertilizers and pesticides for enhanced crop production are usually leached to waterways, leading to detrimental environmental health. Hence, the evolution of smart fertilizers or controlled release of agricultural ingredients is required to reduce and/or minimize leaching and maximize crop productivity. Smart fertilizers include engineered nanoparticles with a large surface area in comparison to their bulk counterparts. This beneficial property can increase soil fertility, crop productivity, and nutrient use efficiency. For a sustainable trajectory, cost-effective and green synthetic methods for the preparation of such nanoparticles are urgently needed. Thus, research on the use of plant extracts as a green approach in the preparation of nanoparticles has largely increased over the years. Whilst several studies have been published on the green synthesis of nanoparticles, the extraction method in relation to nanoparticle quality has not been extensively explored. This review therefore provides the synthetic protocols of nanoparticles from the plant-derived extracts and how plant extraction methods influence the morphology of the nanoparticles and thus their application for plant growth and protection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.