INTRODUCTION

Plant-based processes are used to create zinc oxide nanoparticles in an environmentally responsible manner. These ecologically friendly methods make use of chemicals that are comparatively pollutant-free as well as solvents like water and environmentally acceptable natural extracts. The green synthesis method promotes the use of biological procedures rather than conventional chemical ones, which frequently involve hazardous organic solvents as reducing agents. The environment can tolerate and trust these biological activities. Yeast, fungus, and bacteria are just a few examples of the biological systems that have been effectively used to create nanoparticles. The need to maintain cell cultures, allow for intracellular synthesis, and perform several purification steps make the utilization of microorganisms difficult (Alagumuthu and Kirubha, 2012).

The benefits of ecologically friendly nanoparticle production include the following:

There has been a lot of interest recently in the ecologically friendly production of nanoparticles since the chemical compounds and organic solvents used in conventional chemical processes as reducing agents can occasionally be costly, hazardous, and hazardous (Mason et al., 2012). In contrast to conventional chemistry, green chemistry seeks to limit pollution at its source and prevent waste formation. The usage of environmentally friendly chemicals is the key principle. The biogenic technique stands out for its eco-friendliness even if physical and chemical methods of producing nanoparticles may be quicker and simpler (Anastas et al., 2000b; Reed and Hutchison, 2000).

Green synthesis using Coriandrum sativum leaf extract

Using Coriandrum sativum plant leaf extract, it is feasible to successfully produce ZnO nanoparticles. To begin, add 0.02M aqueous zinc acetate dihydrate while continuously swirling 50mL of pure water. After 10 minutes of stirring, different amounts of Coriandrum sativum aqueous leaf extract (0.25, 0.5, and 1mL) are added. To achieve a pH of 12, a 2.0M NaOH solution is also added, resulting in a light-colored aqueous solution. For the next two hours, the liquid is agitated using a magnetic stirrer. Following the stirring stage, a light-colored precipitate is collected, and impurities are completely eliminated by repeated washes with distilled water and ethanol. After drying the precipitate overnight in a vacuum oven at 60°C, a light-colored powder of ZnO nanoparticles is obtained (Anastas et al., 2000a; Sabir et al., 2014).

Figure 2; Green synthesis using Coriandrum sativum leaf extract

In order to create green zinc oxide nanoparticles, Calotropis gigantea leaf extract was used:

This method is used to investigate the possibility of zinc oxide nanoparticle production by the plant Calotropis gigantea. First, a stirrer heater or hot plate is used to heat 50mL of Calotropis gigantea leaf extract to a temperature between 60 and 80 degrees Celsius. A steady 60 degrees Celsius is now reached while 5 grams of zinc nitrate are added to the solution. Cooking continues until a dark yellow paste forms from the ingredients. The paste is then placed in a ceramic crucible and heated to 400 degrees Celsius for two hours. The final result is a carefully proportioned pale yellow powder. Using a mortar and pestle, the material is roughly ground to facilitate precise description (Stan et al., 2015).

Making Use of Eco-Friendly Acalypha indica Leaf Extract to Produce Zinc Oxide Nanoparticles

After being thoroughly cleansed with double-distilled water, fresh Acalypha indica leaves are crushed in an environmentally responsible manner to extract the essential components. The components are removed, and whatman filter paper is used to filter the mixture. Precursor materials include sodium hydroxide (99% pellet) and zinc acetate dihydrate (99% purity). The dihydrated zinc acetate must be vigorously stirred with distilled water after being added. Extract from Acalypha indica leaves is added after vigorous stirring for 10 minutes. The addition of aqueous 2.0M NaOH, which produces a whitish, pH-12 aqueous solution, has a substantial effect on the size of the resultant ZnO nanoparticles.The liquid is then stirred for a further two hours with a magnetic stirrer. To ensure that the final product is free of impurities, the precipitates are collected and periodically cleaned using distilled water and ethanol. After drying at 60 degrees Celsius in a vacuum oven for an overnight period, a white powder containing ZnO nanoparticles is generated (Gnanasangeetha and Thambavani, 2013).

Using the milky latex of the Calotropis procera, we generated green zinc oxide nanoparticles. Zinc oxide is manufactured at a factory utilizing the milky latex of the Calotropis procera (AK, Maddar) plant.

A Rice-Based Soft Biotemplate for Green Synthesis

The rice plant, Oryza sativa, provides a bioresource that is plentiful, renewable, and has unique qualities, making it a great bio template for the synthesis of many functional nanomaterials. Zinc acetate, sodium hydroxide, and uncooked rice flour are used as precursors in different ratios in the hydrothermal bio template method to create ZnO particles. The reaction is performed for 18 hours at 120 C. Table 1 by Pearton et al. (2003) lists the physical characteristics of wurtzite zinc oxide nanoparticles, such as density, melting temperature, and relative dielectric constant. The size and shape of the resultant ZnO nanoparticles are also significantly influenced by the rice bio template (Ramimoghadam et al., 2013).

GREEN SYNTHESIS OF ZINC OXIDE NANOPARTICLES