A new method for direct preparation of tin dioxide nanocomposite materials

In the current work, a novel combustion method is demonstrated for the direct synthesis of nanocomposite materials. Specifically doped tin dioxide (SnO₂) powders were selected for the demonstration studies due to the key role SnO₂ plays in semiconductor gas sensors and the strong sensitivity of doped SnO₂ to nanocomposite properties. The synthesis approach combines solid and gas-phase precursors to stage the decomposition and particle nucleation processes. A range of synthesis conditions and four material systems were examined in the study: gold - tin dioxide, palladium - tin dioxide, copper - tin dioxide, and aluminum - tin dioxide. Several additive precursors were considered including four metal acetates and two pure metals. The nanocomposite materials produced were examined for morphology, phase, composition, and lattice spacing using transmission and scanning electron microscopy, x-ray diffractometry, and energy-dispersive spectroscopy. The results using the combustion synthesis approach indicate good control of the nanocomposite properties, such as the average SnO₂ crystallite size, which ranged from 5.8 to 17 nm.