Hydrogen generation from splitting water with Al–Bi(OH)3 composite promoted by NaCl

In this paper, a novel Al–Bi(OH) 3 system hydrogen-generating material is investigated. Hydrolysis experiments show that the hydrolysis properties of the Al–10 wt% Bi(OH) 3 composite are significantly improved by doping with sodium chloride, and the Al–10 wt% Bi(OH) 3 –5 wt% NaCl composite has a low activation energy (10.4 kJ mol −1 ). With the further optimization of milling time, the hydrogen yield of Al–10 wt% Bi(OH) 3 –5 wt% NaCl composite reaches 1000 mL g −1 in 1 min. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive spectroscopy and thermogravimetric analysis are applied to characterize the composite and explore the hydrolysis mechanism. The characterization results show that the activation of aluminum mainly comes from three factors: (1) The formation of alumina during ball milling plays an important role in preventing the agglomeration between Al–Bi, Al–Al and Bi–Bi; (2) Bismuth generated during ball milling can form micro-galvanic cell with aluminum to promote the corrosion of aluminum; (3) Sodium chloride as a grinding aid contributes to crush aluminum powder , and chloride ions facilitate the corrosion of aluminum in the hydrolysis process . In addition, the drying method and initial water temperature have a great influence on by-products. The composite is expected to be used in mobile emergency fuel cell due to its rapid hydrogen production capacity.