Micro- and nano-scale hollow TiO2 fibers by coaxial electrospinning: Preparation and gas sensing

We report the preparation of micro- and nano-scale hollow TiO2 fibers using a coaxial electrospinning technique and their gas sensing properties in terms of CO. The diameter of hollow TiO2 fibers can be controlled from 200 nm to several micrometers by changing the viscosity of electrospinning solutions. Lower viscosities produce slim hollow nanofibers. In contrast, fat hollow microfibers are obtained in the case of higher viscosities. A simple mathematical expression is presented to predict the change in diameter of hollow TiO2 fibers as a function of viscosity. The successful control over the diameter of hollow TiO2 fibers is expected to bring extensive applications. To test a potential use of hollow TiO2 fibers in chemical gas sensors, their sensing properties to CO are investigated at room temperature.

Graphical abstractMicrostructures of as-prepared and calcined hollow TiO2 fibers prepared by the electrospinning technique with a coaxial needle. Dynamic response at various CO concentrations for the sensor fabricated with the hollow TiO2 fibers .Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Hollow TiO2 fibers were synthesized using a coaxial electrospinning technique. ► Their diameter can be controlled by changing the viscosity of electrospinning solutions. ► Lower viscosities produce slim hollow nanofibers. ► In contrast, fat hollow microfibers are obtained in the case of higher viscosities. ► Successful control over the diameter of hollow TiO2 fibers will bring extensive applications.