Preparation of Sol-Gel Nano-Composites Containing Copper Oxide and Their Gas Sensing Properties

Sol-gel derived composite materials were prepared with nano-sized copper particles in silica matrix. Nano-sized oxide coatings were grown on the nano-particles of copper by subjecting the composites to a controlled oxidation treatment at different temperatures. The current response of samples with oxide layers of different thickness were studied at fixed temperatures in the range 350–450°C in the presence of different concentrations of CO and NO2. The nano-composites were sensitive to both the gases. The operating temperature and the oxide thickness were found to have significant effect on the sensing properties.