College of Electric Engineering, Key Laboratory for Electronic Materials of Northwest Minzu University, Northwest Minzu University, Lanzhou, Gansu 730030, PR China.
Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, Gansu 730030, PR China.
J Hazard Mater. 2021 Aug 5;415:125662. doi: 10.1016/j.jhazmat.2021.125662. Epub 2021 Mar 16.
Recently, tremendous research interest was stimulated to obtain advanced function materials with hierarchical structure and tailored chemical composition from metal-organic frameworks (MOFs) based precursors. Herein, Bimetal-organic frameworks of Ni-Co-BTC solid microspheres synthesized through hydrothermal method were acted as template to induce multishelled NiO/NiCoO hollow microspheres by annealing treatment. When evaluated as gas sensing material, the optimal hybrid of NiO/NiCoO (the molar ration of NiCo=1.5) multishelled hollow microspheres endowed a high sensitivity (17.86) to 100 ppm acetone with rapid response/recovery time (11/13 s) under low working temperature (160 °C) and the low detection limit reached 25 ppb. The enhanced mechanism was originated from the following aspects: the multishelled hollow architecture provided efficient diffusion path for gas molecules and sufficient active site for gas sensing reaction; the nanoscale p-p heterojunction created at NiO and NiCoO nanoparticles interface amplified the resistance variation by tuning the potential barrier; the potent combination of the "chemical catalytic" effect of NiO and the "electrical catalytic" effect of NiCoO improved the selective acetone detection.
最近，人们极大地激发了研究兴趣，希望从基于金属有机骨架（MOFs）的前体制备具有分级结构和定制化学成分的先进功能材料。在此，通过水热法合成的双金属有机框架 Ni-Co-BTC 固体微球被用作模板，通过退火处理诱导多壳层 NiO/NiCoO 空心微球。当将其作为气敏材料进行评估时，NiO/NiCoO（NiCo 摩尔比为 1.5）多壳层空心微球的最佳杂化在低工作温度（160°C）下对 100 ppm 丙酮表现出高灵敏度（17.86）和快速响应/恢复时间（11/13 s），检测限低至 25 ppb。增强机制源于以下几个方面：多壳空心结构为气体分子提供了有效的扩散路径和充足的气敏反应活性位；在 NiO 和 NiCoO 纳米颗粒界面处形成的纳米级 p-n 异质结通过调节势垒来放大电阻变化；NiO 的“化学催化”效应和 NiCoO 的“电催化”效应的有效结合提高了对丙酮的选择性检测。
