One-pot synthesis of SnO2 hollow microspheres and their formaldehyde sensor application

SnO2 hollow microspheres (HMSs) were successfully synthesized by a one-pot hydrothermal method only using cheap Na2SnO3·3H2O as starting material, without using any templates or surfactants. The characterization results revealed that the SnO2 HMSs, with a diameter range of 450-800 nm, composed of numerous small SnO2 nanoparticles, possess a rough and loose surface shell structure. The SnO2 HMSs were employed to fabricate a gas sensor for detecting formaldehyde. The SnO2 HMS sensor exhibited a high response, quick response/recovery characteristic, good reproducibility, and preferable selectivity to ppm level of formaldehyde, suggesting its promising application as a formaldehyde gas sensor. The SnO2 HMSs can be further applied in other fields such as photocatalysts, dye-sensitized solar cells and lithium-ion batteries.