High response and selectivity of a Cu-ZnO nanowire nanogenerator as a self-powered/active H₂S sensor.

Room-temperature self-powered H2S sensing with high response and selectivity has been realized from a Cu-ZnO nanowire nanogenerator. Upon exposure to 1000 ppm H2S at room temperature, the piezoelectric output voltage of the device (5 at% Cu-ZnO) under compressive force decreases from 0.552 (in dry air) to 0.049 V, and the response is up to 1045, over 8 times larger than that of undoped ZnO nanowires. The selectivity against H2S is also very high at room temperature. The enhanced room-temperature H2S sensing performance can be attributed to the coupling of the piezoelectric screening effect of ZnO nanowires and the synergistic effect of the Cu dopant. This study should stimulate research into designing a new gas sensor for detecting toxic gases at room temperature.