Characterization of (SnO2)1-x(TiO2:CuO)x films as NH3 gas sensor

Abstract

Tin dioxide (SnO2) were mixed with (TiO2 and CuO) with concentration ratio (50, 60, 70, 80 and 90) wt% films deposited on single crystal Si and glass substrates at (523 K) by spray pyrolysis technique from aqueous solutions containing tin (II) dichloride Dihydrate (SnCl2, 2H2O), dehydrate copper chloride (CuCl2.2H2O) and Titanium(III) chloride (TiCl3) with molarities (0.2 M). The results of electrical properties and analysis of gas sensing properties of films are presented in this report. Hall measurement showed that films were n-type converted to p- type as titanium and copper oxide added at (50) % ratio. The D.C conductivity measurements referred that there are two mechanisms responsible about the conductivity, hence it possess two activation energies. Maximum sensitivity 16 % obtained for sample (SnO2)40(TiO2: CuO) 60 toward (NH3) gas at the operating temperature (473 K), whereas faster response time and recovery time were 20 (s) for (SnO2) and (SnO2)20(TiO2:CuO)80 respectively.

Dielectric and gas sensing properties of in situ electrochemically polymerized PPy-MgO-WO3 nanocomposite films

“…where c , d, and a are the capacitance, the thickness, and the area of the sample, respectively . The sensor's response to reducing gas, such as methanol, ammonia, and hydrogen H 2 S is detected through the sensors resistance, where the sensitivity is given by [19,20]: S = (( Rg -Ra) / Ra) x100% (9) if Rg > Ra S = (( Ra -Rg) / Ra) x100% (10) if Ra > Rg where Ra and Rg are the resistance values of the sensor film in clean air and in the measuring gas, respectively . Response time (t res ) refers to the time needed to reach a stable sensor response after a stepwise increase in the stimulus.…”