A Parallel Solid-State NMR and Sensor Property Study on Flower-like Nanostructured SnO2

Hierarchical three-dimensional flower-like nanostructured SnO2 spheres have been used for a parallel gas sensing and solid-state NMR study. The SnO2 spheres exhibited a good response and reversibility for carbon monoxide, methane, methanol, and ethanol. In a parallel solid-state NMR study, surface carbonate species were observed on SnO2 samples after exposed to all sensing gases (CO, CH4, CH3OH, and CH3CH2OH) at different temperatures. After the SnO2 samples were exposed to CO, CH3OH, and CH3CH2OH, the important intermediate species, e.g., surface formate species and acetate species, were also observed, which could be transformed into carbonate species at higher temperatures. The surface carbonate species would be further decomposed on the SnO2 surface and transformed into the final product CO2. This combined sensing and solid-state NMR study provides crucial information for the surface chemistry during the sensing process.