High sensitivity and selectivity of CaCu3Ti4O12-ZnO composites towards acetone gas at room temperature

Detection of low concentration of acetone gas was carried out using porous CCTO-ZnO composites. The CCTO-ZnO composites were prepared via wet mixing method. The effects of ZnO (x = 0, 2, 6, and 10 wt%) addition on the structural, morphological, and optical properties of CCTO-ZnO powder were investigated by XRD, FTIR, FESEM-EDAX, BET, UV-vis, respectively, whereas the acetone gas sensing properties of CCTO-ZnO composites were studied by I-V characteristic. The XRD result showed a polycrystalline structure. The surface morphology of the powder exhibited a uniform distribution with intergranular porous microstructures. BET indicated average pore diameter (10.08, 10.70, 12.91, and 13.76 nm) and surface area (1.003 1.038, 1.594, and 2.029 m(2) g(-1) respectively with increasing amount of ZnO. This is the cause for the reduction of optical transmittance and increase in their energy bandgap (1.97, 2.05, 2.08, and 2.10 eV). All samples depicted good transparency (<= 80%) in the visible region. CCTO with the addition of 10 wt% ZnO composite showed the highest sensitivity and selectivity towards 1 ppm acetone gas. The composites had 1% error from earlier stability performance, and can possibly be utilized for practically applied in the detection of acetone gas.