Preparation of Macro-Porous Tin Oxide for Sensing of Sulfur Compound.

Macro-porous tin oxide was prepared as an enhanced sensing material for sulfur compounds, such as hydrogen sulfide. Poly-methyl-methacrylate (PMMA) was used as a template for the formation of macro-pores. Tin chloride was used as a precursor for the synthesis of tin oxide, and was impregnated over PMMA beads using a rotary vacuum evaporator. The solid Sn/PMMA material was treated thermally for 4 h at 600 degrees C. The porous morphology of tin oxide prepared in this study was observed by scanning electron microscopy. The surface area of this material measured by the nitrogen adsorption method was approximately 56 m2/g. The crystal structure of the porous material analyzed by XRD was a typical structure of tin oxide. The response of macro-porous tin oxide as a chemical gas sensor was measured using an I-V source meter and the change in signal was observed with the repeated injection of hydrogen sulfide and air. The sensing tests for macro-porous tin oxide were carried out at 200 degrees C and the fast response of macro-porous sensing material was also confirmed.