Enhanced and Proficient Soft Template Array of Polyaniline-TiO2 Nanocomposites Fibers Prepared Using Anionic Surfactant for Fuel Cell Hydrogen Storage

Abstract

Porous TiO₂-doped polyaniline and polyaniline nanocomposite fibers prepared by the in situ polymerization technique using anionic surfactant in an ice bath were studied. The prepared nanocomposites were characterized by FTIR spectroscopy and XRD patterns for structural analysis. The surface morphology of the polyaniline and its nanocomposites was examined using SEM images. DC conductivity shows the three levels of conductivity inherent in a semiconductor. Among the nanocomposites, the maximum DC conductivity is 5.6 S/cm for 3 wt.% polyaniline-TiO₂ nanocomposite. Cyclic voltammetry shows the properties of PANI due to the redox peaks of 0.93 V and 0.24 V. Both peaks are due to the redox transition of PANI from the semiconductor to the conductive state. The hydrogen absorption capacity is approximately 4.5 wt.%, but at 60 °C the capacity doubles to approximately 7.3 wt.%. Conversely, 3 wt.% PANI-TiO₂ nanocomposites have a high absorption capacity of 10.4 wt.% compared to other nanocomposites. An overall desorption capacity of 10.4 wt.% reduced to 96% was found for 3 wt.% TiO₂-doped PANI nanocomposites.

Keywords: DC conductivity; hydrogen storage; nanocomposites; polyaniline fiber; surfactant.

Scheme 1

Schematic diagram of PANI—TiO₂ nanocomposite synthesis.

Figure 1

FTIR spectra of PANI and PANI—TiO₂ nanocomposites.

Figure 2

XRD pattern of PANI and PANI—TiO₂ nanocomposites.

Figure 3

SEM image of (a) TiO_2, (b) PANI, (c) 3 wt.%, and (d) 5 wt.% PANI—TiO₂ nanocomposites.

Figure 4

DC conductivity of PANI and PANI—TiO₂ nanocomposites.

Figure 5

Cyclic voltammetry (CV) of PANI and PANI−TiO₂ nanocomposites.

Figure 6

Hydrogen adsorption of PANI and PANI—TiO₂ nanocomposites.

Figure 7

Hydrogen desorption of PANI and PANI—TiO₂ nanocomposites at 60 °C.

Figure 8

Hydrogen absorption/desorption as a function of time.