Rapid and Efficient Detection of NH3 at Room Temperature Using CuO/WS2 Nanohybrids

This work introduces the fabrication of room temperature NH
₃
gas sensors based on CuO/WS
₂
nanohybrids by direct mixing WS
₂
nanosheets and CuO nanocubes in an ultrasonic bath. The ultrathin WS
₂
nanosheets (~5 nm) overlap with each other, and a proportion of CuO nanocubes embedded in the WS
₂
matrix can be observed in the hybrids. The CuO/WS
₂
nanohybrids demonstrate an excellent NH
₃
sensing performance at room temperature, which not only inherit the merits of rapid response ability of WS
₂
nanosheets, but also partially maintain the high sensitivity of CuO nanocubes. Measurements indicate that the CuO/WS
₂
nanohybrids with a mass ratio of 2:1 exhibit a relative high response to NH
₃
(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
₂
nanosheets. Furthermore, the NH
₃
sensing performance of 2:1 CuO/WS
₂
sensor on a PET substrate remains stable after 200 bending cycles, indicating a potential for the development of flexible devices.