Porous polyaniline tube-like/TiO2 nano-heterostructure for sensing hydrogen gas at environmental conditions

Abstract

In this study, porous polyaniline tube-like/TiO 2 nano-heterostructure (PPTH) was prepared by a chemical oxidative polymerization to be used in H 2 sensing. The surface morphology of polyaniline, the content of one-dimensional TiO 2 nanostructures (1D TiO 2 ), and the porosity of PPTH significantly affected the sensing performance of the samples. The response and response/recovery time of gas sensing for H 2 were considered by morphological change of TiO 2 at ambient conditions. The p-n contacts between polyaniline matrix and 1D TiO 2 provided more active sites and facilitated the electrons transport, hence promoting the physisorption of gas molecules. R20 exhibited the highest sensitivity of 9.05 towards 2500 ppm of H 2 gas at the respective response and recovery times of 94 and 374 s. The sensor designed based on F30 exhibited proper long-term stability after one year. The sensing mechanism of PPTH was also studied in detail. • A porous polyaniline tube-like/TiO 2 nano-heterostructure (PPTH) based H 2 sensor. • A high sensitivity, low response/recovery time to H 2 gas at ambient conditions. • A good long-term response. • H 2 gas sensing mechanism of PPTH has also been studied in details.