Paper Title
Green Synthesis of Silica and Calcium Oxide Nanoparticles

Abstract
This paper aims to analyze and provide a review of the several green approaches which are implemented in the synthesis processes of silica nanoparticles synthesis of Calcium Oxide (CaO) nanoparticles. The nanoparticles synthesized using green methods are high quality and have many benefits. In this review, we found out that CaO Nanoparticles are a valuable asset because it incorporates diverse applications in different fields, such as being used as a suitable catalyst for Biodiesel production, as a convincing Drug Mediator, proving to be a good chemisorbed for toxic gases, and shows antibacterial and Antifungal functions, good photocatalytic, antibacterial, and Antifungal functions. The same goes for the synthesis of silica nanoparticles because its sources, which are generally used, are a natural source of silica and do not contain harmful chemical constituents compared to the other synthesis method. Our main focus is to provide fruitful insights into the synthesis of silica and calcium oxide nanoparticles using the green approach, making it more environmentally friendly because it does not hamper the environment. The equipment and chemicals used in green compounds are cheap and readily available in labs. These are the preferred preparation method because it uses non-polluting chemicals and promotes non-toxic solvents such as water and extruded plants. Keywords - Silica Nanoparticles (SiNPs), Calcium Oxide (CaO), American Society for Testing and Materials (ASTM), International Organization for Standardization (ISO), Light Amplification by Stimulated Emission of Radiation (LASER), Energy Dispersive Spectroscopy (EDS).