Enhanced triethylamine gas sensing performance of the porous Zn2SnO4/SnO2 hierarchical microspheres

This paper reports a facile hydrothermal route to synthesis porous Zn2SnO4/SnO2 (ZTO/SnO2) hierarchical microspheres by using chemical etching process with post heat-treatment. Hierarchical ZnSn(OH)(6) microspheres (ZHS-Ms, diameter of 0.4-0.6 mu m) assembled with solid nanoparticles (diameters of 30-80 nm) were firstly prepared via a solvothermal route and then obtained their hollow structure by etching with alkaline solution. The obtained ZHS-Ms that assembled by solid and hollow particles were employed as sacrificial templates for ZTO/SnO2-1 and ZTO/SnO2-2 after a proper annealing process, respectively. It was found that the specific surface area of ZTO/SnO2-2 (26.566 m(2)g (-1)) is higher than ZTO/ SnO2-1 (19.789 m(2)g(-1)) through the etching process. The as-prepared ZTO/SnO2-1 and ZTO/SnO2-2 composites acted as sensing materials for detecting TEA gas. Results demonstrate that the ZTO/SnO2-2 sensor exhibits remarkably higher sensitivity, and better selectivity to TEA vapor at 280 degrees C than the ZTO/SnO2-1 sensor. In addition, the wider range of response linearity and higher response-recovery speed are further realized on the ZTO/SnO2-2 sensor. The enhanced sensing behavior may be attributed to the higher specific surface area and heterojunction of SnO2 and Zn2SnO4. (C) 2019 Elsevier B.V. All rights reserved.