Zhang Yanlin, Jia Chaowei, Wang Qiuyue, Kong Quan, Chen Gang, Guan Hongtao, Dong Chengjun
School of Materials Science and Engineering, Yunnan University, Kunming 650091, China.
Yunnan Province Key Lab of Micro-Nano Materials and Technology, Yunnan University, Kunming 650091, China.
Nanomaterials (Basel). 2019 Jul 24;9(8):1059. doi: 10.3390/nano9081059.
Toluene is extensively used in many industrial products, which needs to be effectively detected by sensitive gas sensors even at low-ppm-level concentrations. Here, NiFeO nano-octahedrons were calcinated from NiFe-bimetallic metal-organic framework (MOFs) octahedrons synthesized by a facile refluxing method. The co-existence of p-Phthalic acid (PTA) and 3,3-diaminobenzidine (DAB) promotes the formation of smooth NiFe-bimetallic MOFs octahedrons. After subsequent thermal treatment, a big weight loss (about 85%) transformed NiFeO nanoparticles (30 nm) into NiFeO porous nano-octahedrons with hollow interiors. The NiFeO nano-octahedron based sensor exhibited excellent gas sensing properties for toluene with a nice stability, fast response, and recovery time (25 s/40 s to 100 ppm toluene), and a lower detection limitation (1 ppm) at 260 °C. The excellent toluene-sensing properties can not only be derived from the hollow interiors combined with porous nano-octahedrons to favor the diffusion of gas molecules, but also from the efficient catalytic activity of NiFeO nanoparticles.
甲苯广泛应用于许多工业产品中，即使在低ppm浓度下也需要通过灵敏的气体传感器进行有效检测。在此，通过简便的回流法合成的NiFe双金属金属有机框架（MOF）八面体煅烧得到NiFeO纳米八面体。对苯二甲酸（PTA）和3,3-二氨基联苯胺（DAB）的共存促进了光滑的NiFe双金属MOF八面体的形成。经过后续热处理，大约85%的大量失重将NiFeO纳米颗粒（30纳米）转变为内部中空的NiFeO多孔纳米八面体。基于NiFeO纳米八面体的传感器对甲苯表现出优异的气敏性能，具有良好的稳定性、快速的响应和恢复时间（对100 ppm甲苯为25秒/40秒），并且在260℃下具有较低的检测限（1 ppm）。优异的甲苯传感性能不仅源于中空内部与多孔纳米八面体相结合有利于气体分子的扩散，还源于NiFeO纳米颗粒的高效催化活性。
