New Solid State Sensor for Gas Detection Based on Carbon Nano-Tube Fortified by Fe2O3-ZnO

Abstract

In this paper multi-wall carbon nano-tubes were prepared by using chemical-thermal vapour deposition method and utilizing molybdenum and iron catalysts and silica alumina-base. Methane was passed over catalyst in optimum condition including passing speed equal to 4 L/min and pressure of 1.27 bar for 2-25 min and temperature of furnace was equal to 980 ºC. Diameter and specific area of nano-tubes were 10-70 nm and 400-560 m²/g respectively. Various quantities of Fe₂O₃-ZnO and 0.1 % palladium were inserted in carbon used for prepared nano-tubes by utilizing vacuum evaporation which its optimum quantity was [2.50 % (1/1 w/w) Fe₂O₃-ZnO] and 0.1 % palladium in order to enhance sensitivity of carbon nano-tubes relative to NH₃ to make sensors appropriate for low temperatures. For investigation instruments and determining physical properties, XRD, SEM and TEM equipments have been applied and prepared. NH₃ sensor is simple, low cost and ready to use in various environment.