Visible photoluminescence and conductometric response of tin oxide nanobelts to NO2: toward a selective gas sensor

The visible photoluminescence of tin oxide nanobelts is quenched by nitrogen dioxide at hundreds of ppb level in a fast (time scale order of seconds) and reversible way. The response is highly selective towards humidity and other polluting species like CO and NH₃. Comparison between conductometric - response to all the examined species is present at a much slower dynamics- and optical results shows that the two effects arise from completely different origin. The results foresee the development of a new class of selective metal oxide gas sensors.