Synthesis of CeO_2-Al_2O_3 nanocomposite by chemical combustion method for NO_2 gas-sensing application

摘要

Composite CeO_2-Al_2O_3 have been successfully synthesized by a convenient solution combustion method. Nitrates of Ce and Al were taken along with fuel Glycine in proper stoichiometric proportion to synthesize C1, C2, C3, and C4. The obtained CeO_2- Al_2O_3 nanocomposite was sintered at 750°C temperature. The XRD patterns of samples confirm the development of CeO_2-Al_2O_3 -nanocomposite with the decrease in average crystallite size from 12.06 nm and 5.54 nm as estimated by the Debye-Scherrer formula. The detailed microanal-ysis showed that dislocation density and microstrain developed increases from C1 to C4. The SEM and TEM study depicts that, well-arranged porous network with pore size ranging between 4 and 12 nm was developed. The quantitative analysis of the samples was established by EDX analysis. Optical study of CeO_2-Al_2O_3 estimate that band gap energy of the sample varies over the range of 2.50 eV to 2.90 eV. The gas sensing nature of CeO_2-Al_2O_3 nanocomposite was thoroughly examined for NO_2 under different operating temperatures and over a different range of concentrations. The maximum response of 156.6% is obtained for NO_2 gas at an operating temperature of 200°C and 100 ppm gas concentration for sample C3. In addition, the quick response of 27 s was noted.