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

## TL;DR

Researchers developed a room-temperature ammonia sensor using CuO/CeO2 nanomaterials, achieving high sensitivity and fast response, powered by a wind-driven triboelectric nanogenerator for environmental monitoring.

## Contribution

The study introduces a CuO/CeO2 heterojunction nanocomposite with enhanced ammonia detection performance and integrates it with a triboelectric nanogenerator for self-powered environmental monitoring.

## Key findings

- The CuO/CeO2 composite achieved a high ammonia response of 70.3% at 100 ppm.
- The sensor exhibited a detection range of 0.5–200 ppm with fast response and recovery times of 13 s and 17 s at 20 ppm.
- The integration of a wind-powered TENG enabled self-powered environmental ammonia monitoring.

## Abstract

Ammonia (NH3) is a common agricultural gas, and its accurate detection is critical to agricultural production. In this study, nano-CuO/CeO2 composites 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 NH3 molecules, 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/CeO2 composites also exhibit excellent extended-term stability and selectivity. Further studies showed that the p-n heterojunction structure of CuO/CeO2 allowed 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/CeO2 heterojunction 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.