Gas-Sensing Study and Applications of Triboelectric Nanogenerator-Powered CuO-Modified CeO2 Nanomaterials for Ammonia Sensor at Room Temperature

Ammonia (NH3) is a common agricultural gas, and its accurate detection is critical to agricultural production. In this study, nano-CuO/CeO2composites were prepared to achieve a wide range of ammonia detection at room temperature. Characterization data verified the composite heterojunction structure of CuO/CeO2, which demonstrates an outstanding large specific surface area for ammonia detection. It provides more active sites for NH3molecules, which brings a very high response to ammonia (70.3% @100 ppm NH3), a large detection range (0.5–200 ppm NH3), and a fast response/recovery time (13 s/17 s @20 ppm NH3). Systematic testing showed that the nano-CuO/CeO2composites also exhibit excellent extended-term stability and selectivity. Further studies showed that the p-n heterojunction structure of CuO/CeO2allowed the composite to retain its gas-sensitive properties to ammonia, in addition to the improved ammonia-detection range of the composite based on the synergistic effect of these two materials. The mechanism of CuO/CeO2heterojunction nanocomposites towards ammonia detection was also elucidated from a microscopic perspective at the molecular level. Finally, a triboelectric nanogenerator (TENG) that can be driven by wind power has been prepared, upon which the feasibility of the combination of the TENG and the ammonia sensor to realize environmental monitoring was investigated.