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

Abstract SnO 2 /Zn 2 SnO 4 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 SnO 2 /Zn 2 SnO 4 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 SnO 2 /Zn 2 SnO 4 porous microspheres (PMSs) that prepared directly from solid ZHS microspheres, the SnO 2 /Zn 2 SnO 4 HPMSs exhibited much higher sensitivity to formaldehyde, demonstrating the improved gas-sensing performance through structural evolution from PMS to HPMS.