A novel method of electrochemically growing ZnO nanorods on graphene oxide as substrate for gas sensing applications

Abstract

The potential of electrochemically deposited ZnO nanorods using graphene oxide (GO) coated inter digital electrode (IDE) as substrate material for gas sensing applications has been reported. For this purpose, GO solution was synthesized via Hummer’s method and coated over IDE of aluminium fabricated on the glass plate. Later ZnO nanorods were deposited on it using electrochemical method. For the structural, morphological and elemental analysis, as-grown nanorods were characterized by XRD, FESEM, EDX and Raman spectroscopy. The gas sensing properties of the sensor were analyzed using customized Gas Sensing Test Rig (GSTR). FESEM micrographs illustrated that ZnO nanorods with hexagonal geometry were deposited on GO homogeneously. In XRD spectra, an intense peak along (002) direction clearly indicate that nanorods possess c-axis orientation. In order to investigate the structural integration of the nanorods, Raman and EDX spectra were also recorded, and their results were found to be in consent with that of XRD analysis. Sensing results revealed that both ZnO nanorods and GO are responsible for change in resistivity of sensor towards the hydrogen gas. Our study indicates that such electrochemically grown ZnO nanorods show prospective for the fabrication of simple and non-hazardous, room temperature gas sensors.