Design and fabrication of metal oxide based gas sensors

Abstract

The research work carried out for Ph.D. thesis entitled Design and fabrication of metal newlineoxide based gas sensors is focused on the nitrogen dioxide (NO2) and hydrogen (H2) gas newlinesensing property of selected transition metal oxides and their composites. newlineSensor technologies have emerged as influential and an incomparable research area newlinewhich has generated various futuristic ideas for sensing applications. Thus, development of newlinenew smart sensors with high potential in sensing gases is need of the present scenario. Gas newlinesensor is a critical element for the gases handling, manufacturing process and during utilization newlineof industrial gases. There is a requirement in growth of sensors due to increasing regulations, newlinestandards and codes that can be satisfied economically by using technology. The NO2 is the newlinesecond largest automobile pollutant. It has detrimental effects to humans as well as newlineenvironment. This gas is one of the most dangerous air pollutants can seriously damage the newlinerespiratory system with very low concentration. The H2 gas is a renewable, green and newlinesustainable energy source. It has the greatest potential to prevent air pollution problems newlineassociated with traditional/ fossil fuel sources. The H2 is abundantly available and its final newlinecombustion product H2O is again a source of H2. However, its flammability over a wide range newlineof concentrations (4% 75%) and auto-ignition (in the temperature of 250 400 oC) makes it newlineextremely dangerous gas. Among various detection methods, gas sensors based on metal oxide newlinesemiconductors are interesting due to their low cost, simple fabrication, low power newlineconsumption, portability etc. newlineNanostructured cupric oxide (CuO) and its composite with multiwalled carbon nanotube newline(MWCNT), heterostructured ferric oxide (Fe2O3) and indium oxide (In2O3) were fabricated/ newlinesynthesized and characterized. These nanoparticles (NPs) were studied for their gas sensing newlineproperty followed by performance analysis through regression technique. The CuO and newlineMWCNT/CuO NPs were subjected for nitric o