synthesis characterization charge transport studies of reduced graphene oxide and its nanocomposited for room temprature gas sensing applictaions

Abstract

newline ABSTRACT newlineGas sensors are fast becoming an imperative part of modern life with extensive newlineapplications in domestic safety, greenhouse gas monitoring for environmental studies, newlineindustrial process control such as methane detection in mines, in automotive industry newlinefor evaluating the exhaust of cars for pollution control check, public security, medical newlineapplications such as electronic noses simulating human olfactory system and chemical newlinewarfare assessment. They are being progressively employed in mass-market newlineapplications, such as in indoor air quality control as well as the more conventional areas newlineof explosive and toxic gas detection. Several potentially hazardous gases such as newlineammonia, nitrogen dioxide, nitrous oxide, hydrogen sulphide, sulphur dioxide and newlinevolatile organic compounds, are either used or released as by-products in several newlineindustrial and commercial processes. Ammonia (NH3), particularly, is a severely toxic newlinegas which is naturally found at sub-ppm levels in the atmosphere. However, a huge newlineamount of NH3 is produced in the fertilizer industry and in industrial fermentation newlineprocesses. Any possible leakage of such large concentrations of ammonia can cause newlinefatal health hazards. Thus, it is essential to systematically evolve gas sensing materials newlineand techniques for fast and efficient room temperature sensing of NH3. Common newlineconventional gas sensors employ techniques such as calorimetric, optoelectronic, gas newlinechromatography, mass spectrometry and acoustic methods for gas detection. These newlinemethods are usually very costly with high power consumption, bulky devices and poor newlineminiaturization due to which they are limited for real-time use. newlineConsequently, chemiresistive gas sensors are being explored due to their low power newlinerequirements, ease of operation and integrability into solid state devices. newlineConventionally, chemiresistive metal oxide semiconductors (MOS) such as zinc oxide newline(ZnO), tin oxide (SnO2), nickel oxide (NiO), tungsten oxide (WO3) etc. have been newlineextensively investigated for their superior sensin