Synthesis and characterization of ZnO-MWCNT nanocomposites for 1-butanol sensing application at room temperature

Zinc oxide and multiwall carbon nanotubes ZnO/(MWCNT) composites were synthesised using wet chemical method and annealed at 400 degrees C for 1 h. They were studied for their microstructure, morphology, optical, electrical and gas sensing properties. SEM analysis showed uniform hexagonal disc like structure of ZnO within the fibers of MWCNT. XRD pattern indicated that the crystalline nature of the sample with hexagonal wurtzite phase. The crystallite size was reduced due to the increased MWCNT concentration. Optical band gap was determined using Tauc's plot. It was decreased from 3.12eV to 2.97eV with increasing MWCNT concentration. FTIR spectra confirmed the Zn-O stretching and carboxylic group in the ZnO composite samples. I-V curve showed the ohmic nature of sample. 1-butanol sensing properties were studied at the room temperature of 27 degrees C in static mode. Experiment results indicated a highest sensitivity with ZnO at 500 ppm. Whereas ZnO/MWCNT composite sensor showed faster response and recovery times.