Controllable Low-Temperature Hydrothermal Synthesis and Gas-Sensing Investigation of Crystalline SnO2 Nanoparticles

SnO2 nanoparticles have been successfully synthesized by a facile hydrothermal method from SnCl2 center dot 2H(2)O, hexamethylenetetramine, and trisodium citrate in water at 120 A degrees C for 12 h. The effects of surfactant and precipitant on SnO2 synthesis were investigated. SnO2 nanoparticles can be synthesized in the temperature range of 120-180 A degrees C with long reaction time in the presence of trisodium citrate. When NaOH was used as precipitant instead of hexamethylenetetramine, it is difficult to obtain SnO2 nanoparticles at 120 A degrees C in the presence of trisodium citrate. SnO2 nanoparticles with an average size of about 5 nm show good crystallinity and excellent sensitivity to ethanol and acetaldehyde in about 55% relative humidity.