Facile preparation of porous In2TiO5–rutile composite nanotubes by electrospinning and sensitivity enhancement in NO2 gas at room temperature

Porous In2TiO5–rutile composite nanotubes (IRCNs) were synthesized via a facile one-step synthesis of the electrospinning approach by using tetrabutyl titanate (TBT), indium nitrate, and polyvinylpyrrolidone (PVP) as a soft-template followed by two-step calcination. The porous composite nanotubes with a bigger surface area have single-crystalline rutile with (1 1 0) crystal plane, and the sensor fabricated by it with a content of 12.5 at% In2TiO5 (IRCN2) has shown a response of 4.04 to 100 ppm NO2 at room temperature (RT), which was 20 times as high as the pure In2TiO5 sensor under the same conditions. The IRCN2 sensor had excellent selectivity compared with other gas species such as CO, H2, NH3, H2S and CH4 at RT. The enhanced sensing properties were attributed to the synergy of integrated In2TiO5 and rutile, heterojunction of single-crystal, and its nanotubular structure. Hence, the IRCN2 sensor has a potential application for the development of novel gas sensors at RT.

Graphical abstractPorous In2TiO5–rutile composite nanotubes (IRCNs) were synthesized using electrospinning approach followed by two-stages calcination. The IRCN2 gas sensors possessed higher stability, selectivity, reversibility and fast response/recovery at room temperature. The enhanced sensing properties were attributed to the synergy of integrated In2TiO5 and rutile, hetero-junction of single-crystal and nanotubular structure.Figure optionsDownload full-size imageDownload high-quality image (174 K)Download as PowerPoint slide