Effect of carbon materials and bismuth particle size on hydrogen generation using aluminum-based composites

A series of activated aluminum/carbon/bismuth composites were prepared and characterized using scanning electron microscope (SEM) and X-ray diffraction (XRD). Then, the performance of these activated aluminum composites with respect to hydrogen generation was explored. The experimental results show that the hydrogen yield and generation rate of the aluminum composite are improved by adding carbon and bismuth to aluminum. In particular, the Al-7.5%nanoBi-2.5%GNS composite milled for 4 h demonstrated the best hydrogen generation in terms of yield and rate. The maximum hydrogen generation rate of Al-7.5%nanoBi-2.5%GNS composite could reach 23.3 mL s⁻¹ g⁻¹ at 30 °C. Besides, the relationship between initial reaction temperature, milling time, and hydrogen generation of these composites was studied. Moreover, the hydrolysis products of these aluminum composites were investigated.