Rapid and Efficient Detection of NH<sub>3</sub> at Room Temperature Using CuO/WS<sub>2</sub> Nanohybrids
Changhui Zhao, Peijun Wang, Gaoqiang Niu, Dan Luo, Quan Wang, Fei Wang
Abstract
This work introduces the fabrication of room temperature NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> gas sensors based on CuO/WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanohybrids by direct mixing WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets and CuO nanocubes in an ultrasonic bath. The ultrathin WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets (~5 nm) overlap with each other, and a proportion of CuO nanocubes embedded in the WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> matrix can be observed in the hybrids. The CuO/WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanohybrids demonstrate an excellent NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> sensing performance at room temperature, which not only inherit the merits of rapid response ability of WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets, but also partially maintain the high sensitivity of CuO nanocubes. Measurements indicate that the CuO/WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanohybrids with a mass ratio of 2:1 exhibit a relative high response to NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (60.7%, at 60 ppm), with good reproducibility, stability and selectivity, which can be attributed to the cooperative effect of efficient gas adsorption of CuO nanocubes and the fast carrier transportation of WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanosheets. Furthermore, the NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> sensing performance of 2:1 CuO/WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensor on a PET substrate remains stable after 200 bending cycles, indicating a potential for the development of flexible devices.