Copper oxide-promoted tin oxide element for highly sensitive and selective detection of H/sub 2/S

The sensing behavior of SnO/sub 2/ elements loaded with various metal oxides in response to H/sub 2/S in air was examined. Among them, CuO-SnO/sub 2/ elements showed unique behavior with extremely high sensitivity and selectivity to H/sub 2/S as well as fast recovery. The optimum operation temperature and CuO loading were found to be 200 degrees C and 3-5 wt.%, respectively. The unique behavior seems to result from the disruption and recovery of p-n junctions at the interface between CuO and SnO/sub 2/ particles, brought about by the sulfurization of CuO and reoxidation of CuS, respectively. The role of CuO is to provide a new design concept of a gas selective semiconductor sensor.<
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