Metal‐Organic Frameworks‐Derived Porous In 2 O 3 Hollow Nanorod for High‐Performance Ethanol Gas Sensor

Abstract 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 In 2 O 3 hollow nanorod (In 2 O 3 ‐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 In 2 O 3 ‐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 In 2 O 3 ‐HNR displayed a hollow interior with porous shell composed by In 2 O 3 nanoparticles (9 nm). Taking advantage of this unique porous nanostructure, In 2 O 3 ‐HNR exhibited a response as high as 6.2 to 5 ppm ethanol at operating temperature of 200 °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 In 2 O 3 ‐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.