Hydrothermal synthesis of SnO2 nanocorals,nanofragments and nanograss and their formaldehyde gas-sensing properties

Morphology plays an important role in the properties of nanomaterials. We successfully synthesized three new SnO₂ morphologies, nanocorals, nanofragments and nanograss, via a simple hydrothermal method with surfactant additives. The final products were characterized by field-emission scanning electron microscopy and X-ray diffraction. We found that the surfactants played a critical role in the synthesis of different SnO₂ nanostructures. In particular, when poly(ethylene glycol) was added as a surfactant, a unique grass-like structure was obtained. The mechanism of formation for this novel structure is discussed. The gas-sensing performance of all the products was investigated. The results show that the nanograss morphology had a superior gas response to formaldehyde than the other morphologies.