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

•Al-doping macro-/nanoporous ZnO was synthesized by a self-sustained decomposition route.•Al-doping macro-/nanoporous ZnO based gas sensor shows a high response towards n-butanol.•Sensor has good repeatability, selectivity, fast response and recovery towards n-butanol.•Al doping porous ZnO could be expected for development of an excellent n-butanol gas sensor.

Macro-/nanoporous Al-doping ZnO powders with enhanced gas sensing properties are prepared by a solution combustion method using Zn(CH3COO)2·2H2O, Zn(NO3)2·6H2O, Al(NO3)3·9H2O, N2H4·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 °C. The mechanisms of responses are also proposed considering the unique material structure.

Graphical abstract2.5 at.% Al-doping macro-/nanoporous ZnO synthesized by self-sustained decomposition of Zn-based complex exhibits ultra-high gas response, selectivity, and a rapid response/recovery time toward n-butanol gas, which attributed the unique structure of macro-/nanoporous ZnO and the Al doping effect.Figure optionsDownload full-size imageDownload as PowerPoint slide