College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, PR China.
College of Chemistry, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, PR China.
ACS Sens. 2024 Oct 25;9(10):5224-5233. doi: 10.1021/acssensors.4c01374. Epub 2024 Oct 14.
Two-dimensional (2D) ZnO nanomaterials are promising for gas sensing, because of their large surface area, abundant active sites, and rapid charge transfer. However, it is challenging to prepare 2D ZnO nanosheet gas sensors with high sensing performance, due to the tight interlayer stack and low adsorptive property of ZnO for NO molecules. Herein, we synthesized Zn-MOF nanosheets employing polyvinylpyrrolidone (PVP) as the structure-directing agent, further through pyrolysis of the Zn-MOF to obtain 2D ZnO nanosheet gas sensors. As anticipated, the 2D ZnO gas sensors exhibited high sensitivity and selectivity for NO, and the optimal sample could achieve a response value of 162 at the working temperature of 160 °C, which is 10 times higher than that of pristine ZnO. Meanwhile, experimental and DFT results showed that PVP plays critical roles in the lateral lattice growth of 2D Zn-MOF nanosheets, while the existence of PVP makes the ZnO gas sensors with rich porous property and more oxygen vacancy after the pyrolysis process, which promoted the adsorption, activity, and surface reaction for NO molecules. It provides a new approach for the application of 2D ZnO nanosheets in the NO detection field.
二维（2D）氧化锌纳米材料因其大的比表面积、丰富的活性位点和快速的电荷转移而在气体传感中具有广阔的应用前景。然而，由于 ZnO 层间堆积紧密以及对 NO 分子的吸附性能低，制备具有高传感性能的 2D ZnO 纳米片气体传感器具有挑战性。在此，我们采用聚乙烯吡咯烷酮（PVP）作为结构导向剂合成了 Zn-MOF 纳米片，然后通过 Zn-MOF 的热解获得了 2D ZnO 纳米片气体传感器。正如预期的那样，2D ZnO 气体传感器对 NO 表现出高灵敏度和选择性，最佳样品在 160°C 的工作温度下可达到 162 的响应值，是原始 ZnO 的 10 倍。同时，实验和 DFT 结果表明，PVP 在二维 Zn-MOF 纳米片的横向晶格生长中起着关键作用，而 PVP 的存在使得 ZnO 气体传感器在热解过程后具有丰富的多孔特性和更多的氧空位，这促进了 NO 分子的吸附、活性和表面反应。它为 2D ZnO 纳米片在 NO 检测领域的应用提供了一种新方法。
