Enhanced Gas Sensitivity of Au-Decorated Flowery WSe₂ 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 WSe₂ nanostructure and its nanocomposite (Au@WSe₂) decorated with Au nanoparticles were fabricated by the hydrothermal method. The performance of a resistive sensor with flowery WSe₂ and Au@WSe₂ 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 WSe₂ can decrease the optimal working temperature from 215 °C to 205 °C and significantly enhance the response of flowery WSe₂. 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@WSe₂ substrate has good responsiveness and selectivity, which makes it a promising candidate for gas detection.