Gold nanoparticles decorated WS2microflakes (Au/WS2) have been synthesized by an in situ chemical reducing process. A chemiresistive-type sensor using as-synthesized Au/WS2heterostructures as sensing materials shows an improved response to different concentrations of ammonia compared to pure WS2at room temperature. As the concentrations of gold nanoparticles increased in heterostructures, response/recovery speeds of the sensors became faster although the sensitivity of the sensor was compromised compared to the sensitivity of the sensor with lower concentrations of Au. In addition, the Au/WS2-based sensor indicated excellent selectivity to formaldehyde, ethanol, benzene and acetone at room temperature. The improved performance of the sensors was attributed to the synergistic effect of electronic sensitization and chemical sensitization between WS2and Au.
Cuixian Luo,Yimeng Dong,Yongjiao Sun,Yurong Huang,Lingrong Xue,Lifang Ren,Daming Wang,Minzhe Qin,Xinke Li
Tungsten disulfide (WS2) is emerging with dazzling visibility as a “layered material beyond graphene and molybdenum disulfide” due to its exquisite tunable electronic, surface structure, high carrier mobility, and physicochemical stability. In this article, In2O3 and Au nanoparticles (NPs) co-modified WS2 microsheets were prepared for detecting NO2 at room temperature (RT). The In2O3 and Au NPs were anchored on the surface of WS2 microsheets, which could be observed by the characterization. The NO2 sensing performance at RT was optimized by adjusting the contents of In2O3 and Au NPs. The proposed gas sensor based on Au1WIn6 (WS2 microsheets co-modified with 6 wt% In2O3 and 1 wt% Au NPs) showed the highest response (46.91 to 50 ppm NO2), limit of detection (LOD; 18.9 ppb), excellent linearity within the test range, and good stability under various relative humidity (RH), bending degrees, and bending times. The excellent result is attributed to the formation of a heterojunction, which increases the number of ionized oxygen adsorption sites and facilitates the reaction between NO2 gas and Au1WIn6. Therefore, it is believed that decorating WS2 microsheets with metal oxide and noble metal NPs is a promising strategy to improve the NO2 sensing property at RT.
危险品化学品经营许可证（带存储）