Porous sheet-like and sphere-like nano-architectures of SnO2 nanoparticles via a solvent-thermal approach and their gas-sensing performances

• Porous sheet-like and sphere-like nano-architectures of SnO2 nanoparticles have been prepared.
• A solvent-thermal approach without surfactant or polymer templates simply by changing the volume ratio of DMF to water.
• The formation mechanism of nano-architectures is proposed in this article.
• Porous sphere-like SnO2 nano-architectures exhibit good sensitivity to the reduce vapors tested.
• Sheet-like materials show better selectivity to ethanol.

Porous sheet-like and sphere-like nano-architectures of SnO2 nanoparticles have been prepared via a solvent-thermal approach in the absence of any surfactant or polymer templates by simply changing the volume ratio of DMF to water. The nano-materials have been characterized by FESEM, XRD, IR, TEM and BET. A mechanism for the formation of nano-architectures is also proposed based on the assembly behaviors of DMF in water. The gas sensors constructed with porous sphere-like SnO2 nano-architectures exhibit much higher sensitivity to the reduce vapors tested, compared to those from porous sheet-like SnO2 materials, while the sheet-like materials show better selectivity to ethanol. The nano-architectures fabricated with the facile method are promising candidates for building chemical sensors with tunable performances.