Controlled Synthesis of ZnO Nanostructures for Sub-ppm-Level VOC Detection

Various ZnO nanostructures, including nanoparticles, nanorods, nanotubes, and nanorings, were synthesized via a controlled synthesis by a facile sonochemical method combined with a chemical etching process. The morphology and structure of the fabricated nanomaterials were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The sensing properties of different ZnO nanostructures toward volatile organic compounds gases at sub-ppm levels were investigated. The differences in the sensing responses of various nanostructures were compared, and reasonable mechanisms are proposed here.