Metal-Organic Frameworks-Derived Porous In2O3 Hollow Nanorod for High-Performance Ethanol Gas Sensor

Designing hollow micro/nano structures for gas sensing materials is highly desirable for boosting gas sensing properties and still remains challenging, especially through a simple and economic way. Herein, porous In2O3 hollow nanorod (In2O3-HNR), which was successfully fabricated by thermal decomposition of an In-MOF (CPP-3) precursor, was applied as gas sensing materials. The pristine CPP-3 and obtained In2O3-HNR were systematically characterized by various techniques, such as XRD, SEM, TEM, TGA-DTA, XPS, Raman and N-2 physisorption. Characterization results indicated that the hexagonal rod-like shape of original CPP-3 was maintained after calcination, whereas the surface became rough and concave. In addition, the obtained In2O3-HNR displayed a hollow interior with porous shell composed by In2O3 nanoparticles (9 nm). Taking advantage of this unique porous nanostructure, In2O3-HNR exhibited a response as high as 6.2 to 5 ppm ethanol at operating temperature of 200 degrees C, fast response and recovery (3 and 4 s, respectively), and good selectivity to ethanol. The excellent ethanol-sensing properties endow this In-MOF templated In2O3-HNR material with a promising application in practical detection of ethanol gas. This method could be extended to the fabrication of other micro/nano structures with well-defined morphology and composition for high-performance gas sensing considering diversity of MOFs family.