A simple sonication assisted green synthesis method was adopted to prepare nickel oxide nanoparticles using Moringa leaf extract as reducing agent and capping agent. The structural, optical, morphological, photocatalytic, and antimicrobial properties of NiO nanoparticles have been analyzed through different techniques X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and UV-vis spectrometer. The average crystallite size of NiO nanoparticles is 12 nm which is well matched with the particle size calculated from TEM micrographs. The FESEM and HRTEM micrographs clearly show the spherical shaped nanoparticles with uniform distribution. The multi-functional applications like anticorrosive, photocatalytic, and antimicrobial activity of NiO nanoparticles are also analyzed. The green synthesis influenced more in the performance of antibacterial activities of NiO nanoparticles for Staphylococcus aureus and Escherichia coli.

Pollution is adding contaminants into the nature that causes an adverse change in the environment. Air pollution is one of the highest mortality risk factors globally. The sources of air pollution in the industries are power plants, chamber process, cleaning, burning of materials, etc. A variety of pollutants emitted into the air such as sulfur dioxide, carbon monoxide, carbon dioxide, ammonia and volatile organic compounds. Particulate Matter (PM) is an air pollutant that is the mixture of solid dust or pollen and liquid droplets with air. Air pollution in industrial workplaces is a major concern and monitoring and management of it to be addressed to protect the industrial workers health from the air pollution effects. The people are suffering from several respiratory and heart issues along with cancer due to increasing air pollution. This device is composed of ESP32 MCU, MQ135 gas sensor, SDS011 optical dust particle sensor, and BME280 humidity and temperature sensor for monitoring the air quality. The gas sensor MQ135 senses the harmful gases present in the environment. SDS011 optical dust sensor senses the PM levels (PM10 and PM2.5) in the atmosphere. The sensor values are evaluated for the Air Quality Index (AQI) and display it on the ThingSpeak IoT platform. Vrituino app has used for a virtual screen with widgets on the mobile phone to monitor the system using the web. In order to improve the real-time performance of the system, an IoT and a cloud computing technology are being used. The ESP32 turns on the fan units to maintain the pollutants within the safe limit when the presence of harmful gases and PM levels exceeds a certain threshold level. This system is essential for industrial work places to adopt measures and control air pollution which increase industrial workers safety.