Thermally sintered aluminum-gallium-indium microcomposites for hydrogen production through water splitting reaction

This paper reports a novel method for synthesizing activated aluminum microcomposite that spontaneously reacts with water at ambient conditions producing hydrogen. The micorcomposite is produced by thermal sintering of aluminum foils that are pre-sprayed with liquid metal microparticles (eutectic gallium indium alloy, EGaIn) particles. The activated microcomposites react instantaneously and rapidly with water producing hydrogen. The volume of produced hydrogen depends primarily on the mass ratio of the liquid metal to aluminum in the microcomposite, and the rate of hydrogen production can be enhanced by raising the reaction temperature. The activated microcomposite has long shelf life and retain more than 70% of its activity after storing for two months under ambient storage conditions. Analysis of microcomposites using SEM, EDS and XRD before and after reacting with water showed that gallium is necessary for activating aluminum and promoting its reaction with water by forming micro-galvanic cells, and that indium plays an important role in catalyzing the reaction and increasing the rate of hydrogen production. This synthesis method is simple, quick and requires simple equipment. The activated aluminum microcomposites produced using this method are suitable for supplying hydrogen to applications that require on-spot hydrogen production such as electric vehicles or other devices running using hydrogen fuel cells.