Abstract In this study, the hydrothermal and Chemical Vapor Deposition (CVD) methods were applied to synthesize the Ni9S8/NiAl2O4 (NAS) nanocomposites by in situ using NiAl-LDH (NA) as a template. A series of structural and morphological features show that the NAS 2-1 nanocomposite (NC) with the three-dimensional (3D) flower-like structure which is composed of ultrathin nanosheets (4.1–4.9 nm) and porosity (about 2 nm). The NAS 2-1 (NA:S mass ratio 1:6) NC sensor exhibited the excellent response (20.30) with ultrafast response time (1.06 s) to 100 ppm NOx at room temperature (RT), and the detection limit can reach to 10 ppb, respectively. The superior gas sensitivity of the NAS 2-1 sensor is primarily due to the particular three-dimensional flower-like nanostructures and the synergy between Ni9S8 and NiAl2O4. The NAS 2-1 sensor is expected to be used as a gas sensing material due to its excellent three-dimensional flower-like structure and outstanding properties at RT.

中文翻译：

---

由超薄多孔纳米片组成的三维花状 Ni9S8/NiAl2O4 纳米复合材料：室温下制备、表征和超快的 NOx 气体传感器

摘要 本研究以NiAl-LDH（NA）为模板，采用水热法和化学气相沉积（CVD）法原位合成Ni9S8/NiAl2O4（NAS）纳米复合材料。一系列结构和形态特征表明，NAS 2-1 纳米复合材料（NC）具有由超薄纳米片（4.1-4.9 nm）和孔隙率（约 2 nm）组成的三维（3D）花状结构。NAS 2-1 (NA:S 质量比 1:6) NC 传感器在室温 (RT) 下对 100 ppm NOx 表现出优异的响应 (20.30) 和超快响应时间 (1.06 s)，检测限可达分别为 10 ppb。NAS 2-1 传感器卓越的气体灵敏度主要归功于特殊的三维花状纳米结构以及 Ni9S8 和 NiAl2O4 之间的协同作用。