Anomalous rheological behavior of poly(1-vinyl-2-pyrrolidone) and CuCl2in solution and their interactions in solid composites

Designed Synthesis of In₂O₃ Beads@TiO₂-In₂O₃ Composite Nanofibers for High Performance NO₂ Sensor at Room Temperature

Porous single crystal In2O3 beads@TiO2-In2O3 composite nanofibers (TINFs) have been prepared via a facile electrospinning method. The beads were formed because of the existence of hemimicelles in pecursor solution. The formation of hemimicelles was attributed to the synergy of tetrabutyl titanate (TBT) and polyvinylpyrrolidone (PVP). Abundant In(3+) ions were drawn toward the ketonic oxygen of PVP resulting in In(3+) ions aggregation. Compared with pristine In2O3 nanofibers (INFs), the as-prepared TINFs exhibited excellent properties for sensing NO2 gas at room temperature (25 °C). The enhanced sensing property was due to much absorbed oxygen and Schottky junctions between the porous single crystal In2O3 beads and the Au electrode of the sensor. The strategy for combining the unique In2O3 beads@TiO2-In2O3 nanofibers structure which possessed superior conductivity and sufficient electrons with the addition of TiO2 offered an innovation to enhance the gas sensing performance.

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 (110) 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.