Enhanced Gas Sensitivity of Au-Decorated Flowery WSe(2) Nanostructures

With the continuous improvement in material life, people are paying more and more attention to air quality; therefore, it is critical to design efficient and stable gas sensor devices. In this work, a flowery WSe(2) nanostructure and its nanocomposite (Au@WSe(2)) decorated with Au nanoparticles were fabricated by the hydrothermal method. The performance of a resistive sensor with flowery WSe(2) and Au@WSe(2) sensors was evaluated by detecting volatile organic compounds such as ethanol, isoamylol, n-butyl alcohol, isopropanol, isobutanol and n-propanol. The results show that Au-nanoparticle-decorated flowery WSe(2) can decrease the optimal working temperature from 215 °C to 205 °C and significantly enhance the response of flowery WSe(2). The response values to isoamylol are the highest (as high as 44.5) at a low gas concentration (100 ppm), while the response values to ethanol are the highest (as high as 178.5) at a high gas concentration (1000 ppm) among the six different alcohols. Moreover, the response is steady and repeatable. The results demonstrate that the Au@WSe(2) substrate has good responsiveness and selectivity, which makes it a promising candidate for gas detection.