'Nano-on-Micro' Approach Enables Synthesis of ZnO Nano-Cactus for Gas Sensing Applications

Abstract We report a “nano-on-micro” approach for growth of a cactus-like nanostructures of zinc oxide (ZnO) for gas sensing application. We use electrospun polymeric fibers doped with catalyst nanoparticles as the template and employ a vapor-liquid-solid (VLS) method to growth of the ZnO nanostructures. Controlling the processing variables in the VLS process yields to growth of needle-like nanostructures of ZnO around the electrospun fibers, which resembles the needles of a cactus. The ZnO nano-cactus features wurtzite ZnO like crystal structure. We investigate the gas sensing capabilities of the ZnO nano-cactus. The ZnO nanostructures show high sensitivity and selectivity for sensing of ethanol gas. The “nano-on-micro” approach enables single step deposition of nanomaterials between electrodes during synthesis, which eliminates post-synthesis steps, and thus demonstrates better compatibility towards device integration for metal oxide nanostructures.