With the progression of society and the rise in human activities, the detrimental effects of atmospheric ammonia on humans and the environment have grown more severe. Given that ammonia is widely utilized in numerous industrial sectors as a gas and is also a highly toxic and corrosive substance posing threats to human health and the environment, there is an immediate requirement for highly sensitive, selective, and precise sensing techniques to enable effective detection of ammonia. In this study, a V2CTx@PANI composite was prepared and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and EDS mapping to confirm the successful combination of the two materials. The composite's sensing performance for ammonia gas at different concentrations (5–100 ppm) and room temperature was also evaluated. The results demonstrated that the V2CTx@PANI composite sensors exhibited significantly improved response to ammonia gas and faster response/recovery times compared to both the pristine V2CTx-based and pure PANI sensors. Additionally, the composite displayed good long-term stability and selectivity in sensing ammonia. The study also provides a systematic discussion of the sensing mechanism, attributing the enhanced performance to the formation of heterojunctions and an abundance of active sites. Furthermore, first-principles calculations of adsorption energy and density of states were used to demonstrate the high selectivity of V2CTx@PANI for ammonia.

中文翻译：

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V2CTx@PANI 纳米复合材料作为用于氨检测的高效室温气体传感器


随着社会的进步和人类活动的增多，大气中氨对人类和环境的不利影响越来越严重。鉴于氨作为气体在众多工业部门中被广泛使用，而且也是一种剧毒和腐蚀性物质，对人类健康和环境构成威胁，因此迫切需要高灵敏度、选择性和精确的传感技术来实现有效检测氨。在本研究中，使用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）和EDS图谱制备了V2CTx@PANI复合材料并对其进行了表征，以证实两种材料的成功结合。还评估了复合材料在不同浓度（5-100 ppm）和室温下的氨气传感性能。结果表明，与原始的基于 V2CTx 的传感器和纯 PANI 传感器相比，V2CTx@PANI 复合传感器对氨气的响应显着提高，响应/恢复时间更快。此外，该复合材料在氨传感方面表现出良好的长期稳定性和选择性。该研究还系统地讨论了传感机制，将性能的增强归因于异质结的形成和丰富的活性位点。此外，利用吸附能和态密度的第一原理计算证明了V2CTx@PANI对氨的高选择性。