First-principles study of ultrasensitive H2S gas sensors based on p-type WS2 hybrid materials
| Autor: | Baldoví, José J., Pérez Paz, Alejandro, Xian, Lede, Rubio, Angel, Alene Asres, Georgies, Kordas, Krisztian |
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| Rok vydání: | 2018 |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Resumen del póster presentado a la International conference on: Novel 2D materials explored via scanning probe microscopy & spectroscopy; celebrada en Donostia.San Sebastián (País Vasco, España) del 25 al 29 de junio de 2018. Gases with different properties, origins, and concentrations are pervasive in our environment. Some of these gases are highly toxic and hazardous, while others are essential for life or indicators of health status. Accordingly, sensors for gas detection and monitoring are needed in various sectors such as environmental protection, industrial process monitoring and safety, amenity, energy saving, health, and food industries. Metal oxide semiconductors stand out as the most common active sensing materials used in practical devices. Among the new types of nanoscopic sensors being studied, layered transition metal dichalcogenide (MX2, M = Mo, W; X = S, Se) nanostructures have recently attracted significant interest. Often compared to graphene and other two-dimensional (2D) nanomaterials, their properties present distinct advantages for electronic, optical, and electrochemical sensors. In this contribution, we explore the gas sensing behaviour of WS2 nanowire-nanoflake hybrid materials and demonstrate their excellent sensitivity (0.043 ppm-1) as well as high selectivity towards H2S relative to CO, NH3, H2, and NO (with corresponding sensitivities of 0.002, 0.0074, 0.0002, and 0.0046 ppm-1, respectively). Gas response measurements, complemented with the results of X-ray photoelectron spectroscopy analysis and first-principles calculations based on density functional theory, suggest that the intrinsic electronic properties of pristine WS2 alone are not sufficient to explain the observed high sensitivity towards H2S. A major role in this behaviour is also played by O doping in the S sites of the WS2 lattice. The results of the present study open up new avenues for the use of transition metal disulphide nanomaterials as effective alternatives to metal oxides in future applications for industrial process control, security, and health and environmental safety. |
| Databáze: | OpenAIRE |
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