ELECTRICAL AND HYDROGEN GAS SENSING PROPERTIES OF ZnO-CuO COMPOSITES

Abstract

Composites of xZnO:CuO with 1 ≤ x ≤ 3 composition ratio were fabricated in the form of pellets by sintering at 800oC. Their electrical conductivity and hydrogen gas sensitivity were examined between 100 and 500oC. Sample consisting of 1.5ZnO:CuO was found to have the highest sensitivity to both 5%H2 and 200 ppm H2. The sensitivity of the samples was found to decrease for the values of x greater than 2. The samples also shows higher sensitivity to 5%H2 than 200 ppm H2 above 250oC. The electrical conductivity of the composites varies with temperature and has a minimum values when the ZnO content is about 60-67 mole% for temperature above 350oC.