SnO2 microspheres were successfully synthesized by a facile hydrothermal method.
SnO2 microspheres are composed of large small spheres with average diameters of about 250 nm.
Small spheres consist of numerous primary nanocrystallites with average sizes of about 8 nm.
SnO2 microspheres have excellent gas sensing properties for formaldehyde gas.
SnO2 microspheres are promising candidate for practical detectors for formaldehyde gas.