Preparation of Hierarchical Nanoporous Al–SiO2/Ni–Mo Composite Electrodes and Their Electrocatalytic Hydrogen Evolution

Hierarchical nanoporous Al–SiO2 particles were prepared in this study by dissolving template method. The hierarchical nanoporous Al–SiO2 particles with hollow structure were analyzed by transmission electron microscope (TEM), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), nitrogen adsorption stripping curves and Barrett-Joyner-Halenda (BJH) pore size distribution curves. Hierarchical nanoporous Al–SiO2/Ni–Mo composite electrodes were prepared by composite deposition of hierarchical nanoporous Al–SiO2 particles onto electroplating bath of Ni–Mo. Results showed that the specific surface area for the hierarchical nanoporous Al–SiO2 sample was 396 m2/g, with pore volume being 1.37 cm3/g and mesoporous pore size being 3.3 nm. The hydrogen evolution electrocatalytic activities for the composite electrodes reached the optimal value when the concentration of the hierarchical nanoporous Al–SiO2 in the electroplating bath was 2 g/L, indicating that their “foam” structure did not only enhance the electrode surface area but also effectively improved the electrocatalytic properties of aluminum and showed that the electrocatalytic hydrogen evolution by the hierarchical nanoporous Al–SiO2/Ni–Mo composite electrodes had more advantages than that of the Ni–Mo electrodes alone.