Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering , Shanghai Jiao Tong University , Shanghai 200240 , People's Republic of China.
ACS Appl Mater Interfaces. 2018 Jul 5;10(26):22640-22649. doi: 10.1021/acsami.8b05811. Epub 2018 Jun 25.
Molybdenum disulfide (MoS), as a promising gas-sensing material, has gained intense interest because of its large surface-to-volume ratio, air stability, and various active sites for functionalization. However, MoS-based gas sensors still suffer from low sensitivity, slow response, and weak recovery at room temperature, especially for NO. Fabrication of heterostructures may be an effective way to modulate the intrinsic electronic properties of MoS nanosheets (NSs), thereby achieving high sensitivity and excellent recovery properties. In this work, we design a novel p-n hetero-nanostructure on MoS NSs using interface engineering via a simple wet chemical method. After surface modification with zinc oxide nanoparticles (ZnO NPs), the MoS/ZnO hetero-nanostructure is endowed with an excellent response (5 ppm nitrogen dioxide, 3050%), which is 11 times greater than that of pure MoS NSs. To the best of our knowledge, such a response value is much higher than the response values reported for MoS gas sensors. Moreover, the fabricated hetero-nanostructure also improves recoverability to more than 90%, which is rare for room-temperature gas sensors. Our optimal sensor also possesses the characteristics of an ultrafast response time of 40 s, a reliable long-term stability within 10 weeks, an excellent selectivity, and a low detection concentration of 50 ppb. The enhanced sensing performances of the MoS/ZnO hetero-nanostructure can be ascribed to unique 2D/0D hetero-nanostructures, synergistic effects, and p-n heterojunctions between ZnO NPs and MoS NSs. Such achievements of MoS/ZnO hetero-nanostructure sensors imply that it is possible to use this novel nanostructure in ultrasensitive sensor applications.
二硫化钼（MoS）作为一种很有前途的气体传感材料，由于其大的比表面积、空气稳定性和各种功能化的活性位点而引起了人们的极大兴趣。然而，基于 MoS 的气体传感器在室温下仍然存在灵敏度低、响应慢和恢复弱的问题，特别是对 NO。制造异质结构可能是调节 MoS 纳米片（NS）本征电子特性的有效方法，从而实现高灵敏度和优异的恢复性能。在这项工作中，我们通过简单的湿化学方法利用界面工程在 MoS NS 上设计了一种新型的 p-n 异质纳米结构。经过氧化锌纳米粒子（ZnO NPs）的表面改性后，MoS/ZnO 异质纳米结构具有优异的响应（5 ppm 二氧化氮，3050%），比纯 MoS NS 高 11 倍。据我们所知，这种响应值比报道的 MoS 气体传感器的响应值高得多。此外，所制造的异质纳米结构还提高了恢复能力，超过 90%，这在室温气体传感器中很少见。我们的最佳传感器还具有超快的响应时间 40 s、10 周内可靠的长期稳定性、出色的选择性和低至 50 ppb 的检测浓度的特点。MoS/ZnO 异质纳米结构的增强传感性能可以归因于独特的 2D/0D 异质纳米结构、协同效应以及 ZnO NPs 和 MoS NSs 之间的 p-n 异质结。MoS/ZnO 异质纳米结构传感器的这些成就表明，这种新型纳米结构有可能用于超灵敏传感器应用。
