Clarifying the polyaniline effect on superior electrochemical performances of hydrogen storage alloys

Agile soft template array fabrication of one-dimensional (1D) polyaniline nanocomposite fibers for hydrogen storage

Polyaniline-Zn/V2O5 nanocomposites were prepared in the presence of toluene-4-sulfonic acid monohydrate as an anionic surfactant via an in situ oxidation polymerization method. The structural study of the nanocomposites was carried out using FTIR and XRD analysis, and their surface morphology was characterized through SEM analysis. The BET surface area of a 3 wt% nanocomposite was 386 m2 g-1, which is higher compared to that of PANI. The Kelvin two probe method was used to study DC conductivity, and it was found that the conductivity increases with increasing temperature. Among all the PANI nanocomposites, 3 wt% PANI-Zn/V2O5 shows a high conductivity of 13.8 S cm-1. Cyclic voltammetry results show the characteristic oxidation-reduction peaks at 0.93 V and 0.24 V for polyaniline and its nanocomposites, respectively. Hydrogen absorption studies were carried out using volumetric sorption measurement technique. At room temperature, it was found that the hydrogen adsorption capacity of polyaniline fibres is about 4.5 wt%, and its absorption capacity increases two-fold upon increasing the temperature up to 60 °C. Conversely, the 3 wt% PANI-Zn/V2O5 nanocomposite showed a high absorption capacity of 6.6 wt% compared with other compositions, which is may be due to the presence of nitrogen (N) molecules in polyaniline and its particular porous fiber architecture.

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

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.

Preparation of Anionic Surfactant-Based One-Dimensional Nanostructured Polyaniline Fibers for Hydrogen Storage Applications

Polyaniline fibers were prepared in the presence of anionic surfactant in an ice medium to nucleate in one dimension and were compared to bulk polyaniline prepared at an optimum temperature. Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) were used to investigate the structural analysis of the prepared samples. A conductivity study reveals that polyaniline fibers have high conductivity compared to bulk polyaniline. Hydrogen storage measurements confirm that the polyaniline fibers adsorbed approximately 86% of the total actual capacity of 8–8.5 wt% in less than 9 min, and desorption occurs at a lower temperature, releasing approximately 1.5 wt% of the hydrogen gases when the pressure is reduced further to 1 bar.

A Bird's-Eye View on Polymer-Based Hydrogen Carriers for Mobile Applications

Globally, reducing CO2 emissions is an urgent priority. The hydrogen economy is a system that offers long-term solutions for a secure energy future and the CO2 crisis. From hydrogen production to consumption, storing systems are the foundation of a viable hydrogen economy. Each step has been the topic of intense research for decades; however, the development of a viable, safe, and efficient strategy for the storage of hydrogen remains the most challenging one. Storing hydrogen in polymer-based carriers can realize a more compact and much safer approach that does not require high pressure and cryogenic temperature, with the potential to reach the targets determined by the United States Department of Energy. This review highlights an outline of the major polymeric material groups that are capable of storing and releasing hydrogen reversibly. According to the hydrogen storage results, there is no optimal hydrogen storage system for all stationary and automotive applications so far. Additionally, a comparison is made between different polymeric carriers and relevant solid-state hydrogen carriers to better understand the amount of hydrogen that can be stored and released realistically.