Key Laboratory of Optoelectronic Technology and System of Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, PR China.
Key Laboratory of Agricultural Information Service Technology of Ministry of Agriculture, Agricultural Information Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
Anal Chem. 2020 Aug 18;92(16):11007-11017. doi: 10.1021/acs.analchem.9b05623. Epub 2020 Jul 31.
Surmounting the issues of high-sensitivity and room-temperature detection toward trace NO gas is of paramount importance in the fields of human health and ultralow emission. Recently, black phosphorus (BP), a novel two-dimensional material, has gained considerable interest to achieve this goal. However, related work is far from satisfactory due to sluggish response, insufficient recovery, and fragile stability. In this scenario, we report on an inspiring NO sensor featuring composite film of few-layer BP nanosheets and zinc oxide (ZnO) nanowires serving as the sensing layer. Compared with BP-only counterpart, BP-ZnO sensor exhibited enhanced performance including boosted response (74% vs. 37.7% toward 50 ppb, which was among the best performances of BP involved NO sensors), accelerated response speed, better long-term stability, and strengthened humidity-repelling properties. In addition, excellent selectivity toward trace NO gas was revealed. These improvements could be ascribed into porous film, abundant sorption sites, numerous heterojunctions, and passivation effect of ZnO nanowires on BP nanosheets. Furthermore, the proposed basic-solution assisted BP exfoliation favored film deposition, and enabled versatile composition design involving BP nanosheets in the future. In brief, the as-prepared BP-ZnO NO sensors paved the avenue for further BP applications and enriched its underlying transduction mechanism in gas sensing.
克服痕量 NO 气体的高灵敏度和室温检测问题在人类健康和超低排放领域至关重要。最近，黑磷 (BP)，一种新型二维材料，已经引起了相当大的兴趣，以实现这一目标。然而，由于响应缓慢、恢复不足和脆弱的稳定性，相关工作远未令人满意。在这种情况下，我们报告了一种令人鼓舞的 NO 传感器，其特征在于由少层 BP 纳米片和氧化锌 (ZnO) 纳米线组成的复合薄膜作为传感层。与仅含 BP 的传感器相比，BP-ZnO 传感器表现出增强的性能，包括增强的响应（50ppb 时的 74%，与 BP 相关的 NO 传感器中最好的性能之一）、更快的响应速度、更好的长期稳定性和增强的抗湿性。此外，还揭示了对痕量 NO 气体的优异选择性。这些改进可以归因于多孔薄膜、丰富的吸附位点、大量的异质结以及 ZnO 纳米线对 BP 纳米片的钝化作用。此外，所提出的碱性溶液辅助 BP 剥离有利于薄膜沉积，并为未来涉及 BP 纳米片的多功能成分设计提供了可能。总之，所制备的 BP-ZnO NO 传感器为进一步的 BP 应用铺平了道路，并丰富了其在气体传感中的基础转换机制。
