The selective detection of harmful gases is of great significance to human health and air quality, triggering the need for special customizations of sensing material structure. In this study, we prepared a novel SnS₂/black phosphorus (BP) two-dimensional (2D)-2D heterostructure via the in situ hydrothermal growth of SnS₂ nanosheets on exfoliated BP lamellae for NO₂ sensing applications. In the SnS₂/BP composite, the holes with high oxidizability in p-type BP could oxidize Sn²⁺ into Sn⁴⁺, thus inhibiting the formation of Lewis acidic S vacancies. This Sn²⁺/Lewis acidity suppression of the composite was further confirmed by X-ray photoelectron spectroscopy and acidic double-layer capacitance analyses, and promoted the adsorption and detection of acidic NO₂. Owing to its valence and Lewis acidity engineering, the SnS₂/BP heterostructure sensor could detect trace levels of NO₂ as low as 100 ppb (parts per billion) with high response, fast response/recovery, good stability, and selectivity at room temperature. The high absorption energy of NO₂ (−0.74 eV), as indicated by the density functional theory calculations, suggests that NO₂ was chemically adsorbed on the SnS₂/BP surface, which was also evidenced by the in situ Raman spectroscopy results. This work opens up interesting opportunities for the rational design of highly efficient NO₂ gas sensors through Lewis acidity modification and interface engineering.

有害气体的选择性检测对人类健康和空气质量具有重要意义，引发了对传感材料结构进行特殊定制的需求。在本研究中，我们通过在剥离的BP片层上原位水热生长SnS ₂纳米片，制备了一种新型SnS ₂ /黑磷(BP)二维(2D)-2D异质结构，用于NO ₂传感应用。在SnS ₂ /BP复合材料中，p型BP中具有高氧化性的空穴可以将Sn ²⁺氧化成Sn ⁴⁺ ，从而抑制Lewis酸性S空位的形成。 X射线光电子能谱和酸性双层电容分析进一步证实了复合材料的Sn ²⁺ /Lewis酸性抑制作用，促进了酸性NO ₂的吸附和检测。由于其化合价和路易斯酸度工程，SnS ₂ /BP异质结构传感器可以检测低至100 ppb（十亿分之一）的痕量NO ₂ ，并且在室温下具有高响应、快速响应/恢复、良好的稳定性和选择性。密度泛函理论计算表明NO ₂的高吸收能(-0.74 eV)表明NO ₂化学吸附在SnS ₂ /BP表面上，原位拉曼光谱结果也证明了这一点。这项工作为通过路易斯酸度修饰和界面工程合理设计高效 NO ₂气体传感器开辟了有趣的机会。