Electrospinning of mesoporous p-type In 2 O 3 /TiO 2 composite nanofibers for enhancing NO x gas sensing properties at room temperature

In this paper, a series of loose and porous p-type In2O3/TiO2 composite nanofibers (ITCN) has been synthesized via a facile synthesis using an electrospinning approach, followed by an appropriate thermal treatment under ambient conditions. It was found that the ITCN, with an In2O3 composite content of 14.3 at% (ITCN2), which had lots of loose pores (approximate size of 4–6 nm) in the nanofibers (NFs), made of nanoparticles (7–12 nm), exhibited a short response time of 3 s at 97 ppm and a low detection limit of 97 ppb to NOx, which was over 9 times higher than the response of pure TiO2 nanofibers at room temperature. The ITCN2 performance came from the composite In3+ as an ionic charge-compensating and highly electrically conductive agent, which resulted from adding a large number of gas sensing active sites and increased the conductivity. Hence, the p-type In2O3-composite TiO2 has potential for the development of novel gas sensors at room temperature.