Flash synthesis of Al-doping macro-/nanoporous ZnO from self-sustained decomposition of Zn-based complex for superior gas-sensing application to n-butanol

Macro-/nanoporous Al-doping ZnO powders with enhanced gas sensing properties are prepared by a solution combustion method using Zn(CH3COO)(2)center dot 2H(2)O, Zn(NO3)(2)center dot 6H(2)O, Al(NO3)(3)center dot 9H(2)O, N2H4 center dot H2O and C2H5NO2 as precursors. Characterization by TEM, SEM and BET techniques demonstrates that the Al-doping ZnO powders have a coral-like morphology with a hierarchically porous structure from macro pores, with the wall containing smaller mesopores. The gas-sensing characteristics of the ZnO samples with different Al-doping concentrations are investigated and the results indicate that the gas sensor prepared from 2.5 at% Al-doping ZnO powders shows the highest gas sensitivity and selectivity towards n-butanol. A maximum gas response of 751.95 towards 100 ppm n-butanol is achieved at the operating temperature of 300 degrees C. The mechanisms of responses are also proposed considering the unique material structure. (C) 2016 Elsevier B.V. All rights reserved.