Preparation of porous tin dioxide powder by ultrasonic spray pyrolysis and their application to sensor materials

摘要

Porous SnO_2 powders have been prepared by pyrolysis of atomized aqueous SnCl_2 or SnCl_4 precursor solutions containing polymethyl-methacrylate (PMMA) microspheres. The diameter of macropores existing in the porous SnO_2 powders (about 400-800 nm in diameter) was about 150-200 nm. In addition, the wall thickness of the porous SnO_2 powder prepared from SnCl_2 was presumed to be thinner than that prepared from SnCl_4. A SnO_2 sensor fabricated from the powder prepared by pyrolysis of the aqueous SnO_2 solution at 1100 ℃ showed the highest response to 1000 ppm H_2 in air among the sensors tested.