In this work, flake-flower NiO was successfully prepared via a facile hydrothermal method. The microstructure of the synthesized sample was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We find that the hierarchical flake-flower structure was assembled by numerous nanosheets with different size and shape. The fabricated sensor based on the obtained microstructure exhibited excellent gas sensing performance including high response, outstanding selectivity and stability toward 5 ppm CO at the optimal working temperature of 250°C. A plausible gas sensing mechanism was given out to explain how the nanosheet assembly morphology affects the gas sensing performance of the flake-flower structure.

在这项工作中，通过简便的水热法成功制备了片状花状的NiO。通过X射线粉末衍射（XRD），扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征了合成样品的微观结构。我们发现分层的片状花结构是由许多具有不同大小和形状的纳米片组装而成的。基于获得的微结构制造的传感器在250°C的最佳工作温度下具有出色的气体感应性能，包括高响应，出色的选择性和对5 ppm CO的稳定性。给出了合理的气体传感机制，以解释纳米片组装形态如何影响片花结构的气体传感性能。