Metal Oxide Nanostructure Based Humidity and VOC Sensors with IoT Enabled Smart Interface to Prevent Industrial Mishaps and Improve Human Life

Abstract

Industrial accidents and acute gas exposure are becoming more common, causing serious impacts on productivity and worker safety. Detection and control of humidity are also very important in the present globalization scenario. As per the Occupational Safety and Health Administration (OSHA), the gas emission concentration once exceeding its certain level may cause an explosion, if workers come into contact with such gases for a short or long time, it can cause very lethal diseases related to vital organs of their body. Conventional gas sensors may be reliable for detecting such hazardous gases however, in the development of smart technologies, they are failing to fit in portable and miniaturised devices like smartphones, smartwatches and other applications like smart cities and industries due to their inbuilt disability. For decades, metal oxide semiconductor (MOS) gas sensors have offered effective solutions for the miniaturization of sensors through integrated circuits (IC) for detecting gases more easily, however, despite the revolutionary improvements in technology, their IoT integration is difficult mainly due to their high operational temperatures (150 to 400oC). To address this issue, there is plenty of room available towards developing and incorporating MOS-based energy-efficient gas sensors in IoT integration. With this motivation, in this study, we deployed energy-efficient gas sensors using conventionally synthesized cheaper and earth-abundant materials-based metal oxide semiconductors like MnFeand#8322;Oand#8324; (MFO), Bi2WO6 (BWO) and TiO2/MoO3 to detect humidity and harmful gases like triethylamine (TEA) and n-butanol. These sensors work in three energy-efficient ways including ambient light, visible light, and UV light-induced photovoltaic way to improve performance newline