Improved formaldehyde-sensing performance of SnO2/Zn2SnO4 nanocomposites by structural evolution

SnO2/Zn2SnO4 hollow microspheres with porous shell (HPMSs) were successfully prepared by using ZnSn (OH)6 (ZHS) hollow microspheres (HMSs) as sacrificial templates, which were pre-synthesized via a fast solid-state grinding method combined with subsequent chemical etching process. The obtained samples were characterized by XRD, SEM, TEM, and N-2 adsorption-desorption, respectively. Results indicated that the diameter of the prepared SnO2/Zn2SnO4 HPMSs were around 300-700 nm and their shell-thickness was about 50 nm. On the shell of the composite HPMSs, a large number of 5-20 nm pores were in situ created. In comparison with the SnO2/Zn2SnO4 porous microspheres (PMSs) that prepared directly from solid ZHS microspheres, the SnO2/Zn2SnO4 HPMSs exhibited much higher sensitivity to formaldehyde, demonstrating the improved gas-sensing performance through structural evolution from PMS to HPMS. (C) 2017 Elsevier B.V. All rights reserved.