Synthesis of layered hierarchical porous SnO2 for enhancing gas sensing performance

Layered hierarchical porous SnO2 (LHP-SnO2) have been synthesized by a two-step method, in which pure SnO2 nanoparticles(NPs) with the diameter about 3.2 nm were prepared firstly through a hydro-thermal method, and then LHP-SnO2 were prepared by utilizing polystyrene (PS) microspheres as a template and SnO2 NPs as a precursor. The as-prepared sample consisted of porous SnO2 layers, in which each layer presents a three-dimensional random arrangement of macropores with average pore diameter of about 260 nm. The Nitrogen adsorption–desorption analysis implied that the sample was characterized with large surface area of 140.67 m2/g and extensive micropores and mesopores structure. Compared with pure SnO2 NPs, the LHP-SnO2 exhibited an obvious improvement in gas sensing properties. These results indicate that the layered hierarchical porous structure possess potential application in sensing materials.