Xu Yanling, Li Xiaofang, Song Yangyang, Zhang Ruiguang, Yuan Wenjing, Xia Dan, Xue Qingzhong, Yin Fuxing
School of Materials Science & Engineering, Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, Hebei University of Technology, Tianjin 300130, China.
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, Qingdao, Shandong 266580, China.
ACS Appl Mater Interfaces. 2021 Oct 27;13(42):50270-50280. doi: 10.1021/acsami.1c16776. Epub 2021 Oct 12.
Black phosphorus (BP) nanosheets have been receiving attention for gas sensing showing superior sensitivity and selectivity among various two-dimensional materials. However, the instability of BP nanosheets due to chemical degradation, especially in humid environments, has severely limited their potential applications. Here, we propose to control the chemical stability of BP nanosheets through modifying their end groups via silanization treatment. Compared with other chemical passivation methods, the end group modification strategy proposed here can be well-controlled and results in little variation in the electronic structure of the puckered phosphorus plane. The results show that modification with fluoroalkylsilane leads the hydrophilic BP to become hydrophobic and exhibits extended chemical stability in oxidizing, humid environments. The sensitivity of fluoroalkylsilane-modified BP (F-BP) to NO improved by 3.9-fold in comparison with that of pristine BP nanosheets. More importantly, the NO sensing response could remain stable under changing relative humidity ranging from 5% to 95%. Such excellent sensing performance is ascribed to the strong interaction between NO and BP decorated with fluoroalkylsilane, as confirmed by density functional theory calculations. This work offers an effective means for preventing degradation of BP in ambient environments and provides a promising solution to solve the issue regarding humidity dependence in gas sensors.
黑磷（BP）纳米片因其在气体传感方面的卓越灵敏度和选择性，在各种二维材料中备受关注。然而，BP纳米片由于化学降解而不稳定，尤其是在潮湿环境中，这严重限制了它们的潜在应用。在此，我们提议通过硅烷化处理修饰其端基来控制BP纳米片的化学稳定性。与其他化学钝化方法相比，本文提出的端基修饰策略可以得到很好的控制，并且褶皱磷平面的电子结构变化很小。结果表明，用氟代烷基硅烷修饰可使亲水性的BP变得疏水，并在氧化、潮湿环境中表现出更长的化学稳定性。与原始BP纳米片相比，氟代烷基硅烷修饰的BP（F-BP）对NO的灵敏度提高了3.9倍。更重要的是，在5%至95%的相对湿度变化下，NO传感响应能够保持稳定。密度泛函理论计算证实，这种优异的传感性能归因于NO与氟代烷基硅烷修饰的BP之间的强相互作用。这项工作为防止BP在环境中降解提供了一种有效手段，并为解决气体传感器中湿度依赖性问题提供了一个有前景的解决方案。
