Realization of H2S sensing by Pd-functionalized networked CuO nanowires in self-heating mode

In this study, we fabricated pristine and Pd-functionalized CuO nanowires (NWs) for H2S gas sensing. The CuO NWs were synthesized using a vapor-liquid-solid method and the Pd functionalization was achieved by ultraviolet irradiation of a Pd precursor solution in the presence of the CuO NWs. The characterization results confirmed the formation of pristine and Pd-functionalized CuO NWs with favorable compositions and morphologies. The gas-sensing response of the NWs towards H2S was enhanced by the Pd functionalization, at 25-100 degrees C. Moreover, self-heating tests showed that the Pd-functionalized gas sensors exhibited a selective response to H2S gas when a low voltage (5 V) was applied. The superior performance of the Pd-functionalized gas sensor was attributable to not only the catalytic effects of both CuS and Pd but also the CuO/Pd heterostructures. The results demonstrate that the fabricated H2S sensors are energy-efficient and could be used in various electronic devices.