ZnO nanoarchitectures: Ultrahigh sensitive room temperature acetaldehyde sensor

In this work, undoped and transition metals (Co, Ni and Cu) doped ZnO nanoarchitectures were deposited on glass substrates by simple chemical spray pyrolysis technique. The obtained ZnO nanoarchitectures were characterized using X-ray diffractometer (XRD), scanning electron microscope (SEM), UV-vis spectrophotometer and electrometer to study their structural, morphological, optical and sensing properties respectively. The structural and morphological results revealed that transition metal doping effectively changed the microstructures and distorted the preferential orientation of (002) crystal plane with reference to the undoped ZnO. Acetaldehyde sensing characteristics of the undoped and doped ZnO nanoarchitectures were investigated. The sensing response towards 10 ppm was found to be 2.85, 800, 2.59 and 21.36 for the undoped, Co, Ni and Cu-doped ZnO nanostructures respectively. Co-doped ZnO nanostructure showed an excellent sensing response over a wide concentration range of 10-500 ppm of acetaldehyde. Moreover the sensing elements showed high selectivity towards acetaldehyde when exposed to 7 different vapours. Ultrahigh sensitivity and selectivity observed for Co-doped ZnO nanoarchitecture revealed its identity as a potential candidate for detecting acetaldehyde in various applications. (C) 2015 Elsevier B.V. All rights reserved.