Synthesis of carbon nanotubes and ZnO nanocomposites for IR sensing

The decoration of metal oxide semiconducting nanoparticles upon the side walls of multi-wall carbon nanotubes (MWCNTs) is examined to create the defects attached with the -COOH group. The walls of the MWCNTs are modified by the ZnO nanoparticles to decrease the resistance of ZnO nanoparticles. The sensitive MWCNT-based ZnO semiconductor (MWCTs/ZnO) nanostructures are synthesized through the bottom-up approach known as co-precipitation method. Some spherical zero-dimensional and elongated structures are also studied. Three samples of MWCNT-based ZnO nanoparticles are synthesized at 65 °C, 80 °C, and 90 °C. The XRD results show that the major diffraction plane of samples has wurtzite hexagonal structure. SEM analysis show that ZnO nanoparticles made the cluster of agglomeration on the walls of the MWCNTs. TEM results show that some of the particles are in spherical shaped and some are elongated. It is observed that the carboxylate group such as COOH on the side walls of the MWCNTs has greater sensitivity 0.36% toward infrared radiations. Moreover, the infrared sensing response of the MWCNT-based ZnO nanosensor increased by varying their synthesizing temperature.