Functionalized titania nanotube composite membranes for high temperature proton exchange membrane fuel cells
ABSTRACT In this study, functionalized titania nanotubes (F-TiO2-NT) were synthesized by using 3- mercaptopropyl-tri-methoxysilane (MPTMS) as a sulfonic acid functionalization agent. These F-TiO2-NT were investigated for potential application in high temperature hydrogen polymer electrolyte membrane fuel cells (PEMFCs), specifically as an additive to the proton exchange membrane. Fourier transform infrared spectroscopy (FT-IR) and X-ray photo- electron spectroscopy (XPS) results confirmed that the sulfonic acid groups were successfully grafted onto the titania nanotubes (TiO2-NT). F-TiO2-NT showed a much higher conductivity than non-functionalized titania nanotubes. At 80 C, the conductivity of F-TiO2-NT was 0.08 S/cm, superior to that of 0.0011 S/cm for the non-functionalized TiO2-NT. The F-TiO2-NT/Nafion composite membrane shows good proton conductivity at high temperature and low humidity, where at 120 C and 30% relative humidity, the proton conductivity of the composite membrane is 0.067 S/cm, a great improvement over 0.012 S/cm for a recast Nafion membrane. Based on the results of this study, F-TiO2-NT has great potential for membrane applications in high temperature PEMFCs.
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ABSTRACT: Polyethersulphone (PES) membranes have been widely applied in various separation applications such as microfiltration, ultrafiltration and nanofiltration. This has occurred as these membranes are easy to form, have good mechanical strength and good chemical stability (resistant to acidic or alkaline conditions) due to the presence of aromatic hydrocarbon groups in the structure. PES membranes are commonly fabricated through the phase inversion method due to the simplicity of the process. However, PES membranes are generally hydrophobic, which usually requires them to be modified before application. In most cases, these methods can reduce the hydrophobicity of the membrane surface and thus reduce membrane fouling during application. This review will further discuss the recently developed UV-induced modifications of PES membranes. The UV-induced grafting method is easy to apply to existing PES membranes, with or without the need for a photo-initiator. Additionally, nanoparticles entrapped in PES membranes subsequently exposed to UV-irradiation have been reported to possess photo-catalytic activity. However, UV-irradiation methods still require special care in order to produce membranes with the best performance.Arabian Journal of Chemistry 07/2013; 360. DOI:10.1016/j.arabjc.2013.07.009 · 2.68 Impact Factor
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ABSTRACT: Fuel cell technology is one of the alternative energy sources for the next generation. Although this technology has proven to be one of the main methods for producing new energy sources, fuel cell technology still has some problems that hinder fuel cell commercialization. Recently, new ideas on titanium dioxide are introduced as potential solution in several applications in fuel cell technology. Thus, this article presents an overview on the applications of titanium dioxide and highlights the unique properties and benefits of titanium dioxide in fuel cell technology.Journal of Power Sources 03/2015; 278. DOI:10.1016/j.jpowsour.2014.12.014 · 5.21 Impact Factor
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ABSTRACT: Nano-composites play a key role in performance improvements of hydroxide conductors employed in a wide range of alkaline-electrochemical systems such as fuel cells and metal-air batteries. Graphene Oxide (GO) nanosheets are considered to be outstanding nano-fillers for polymeric nano-composites on account of their excellent physicochemical strength and electrochemical properties. In this work, a fast hydroxide conductor was developed based on a chemically-modified GO nano-composite membrane. The high surface area of GO was functionalized with highly stable hydroxide-conductive groups, using dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DMAOP) precursor, named QAFGO, and then composed with porous polybenzimidazole PBI (pPBI) as a well suited polymeric backbone. The nano-composite exhibited outstanding hydroxide conductivity of 0.085 S cm-1, high physicochemical strength, and electrochemical stability for 21 days. An alkaline fuel cell (AFC) setup was fabricated to determine the functionality of QAFGO/pPBI nano-composite in an alkaline-based system. The high AFC performance with peak power density of 86.68 mW cm-2, demonstrated that QAFGO/pPBI nano-composite membrane has a promising potential to be employed as a reliable hydroxide conductor for electrochemical systems working in alkaline conditions.ACS Nano 02/2015; DOI:10.1021/nn507113c · 12.03 Impact Factor