Fabrication and Electrocatalytic Activity of Hierarchically Nanoporous Ti–SiO2/Ni–Mo Composite Electrode for Hydrogen Evolution

TiO2 nanoparticles with average diameter of 510 nm were prepared by sol–gel surfactants, and the hierarchically nanoporous Ti–SiO2 particles were further prepared using in-situ method. The hierarchically nanoporous Ti–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. Finally, the hierarchically nanoporous Ni–Mo composite electrodes were prepared using the TiO2 nanoparticles or nanoporous Ti–SiO2 particles as composite particles respectively, and the influence of the concentration of composite particles on the electrocatalytic activities of Ni–Mo composite electrodes for hydrogen evolution were investigated by polarization curves. The results showed that the diameter of Ti–SiO2 particles was from 200 nm to 500 nm, and specific surface area was 573 m2/g with pore volume of 1.19 cm3/g and mesopore size of 3.2 nm. The TiO2/Ni–Mo and Ti–SiO2/Ni–Mo composite electrodes were fabricated by electrodeposition with TiO2 nanoparticles and nanoporous Ti–SiO2 particles as composite particles respectively. The electrocatalytic activities of TiO2/Ni–Mo and Ti–SiO2/Ni–Mo composite electrodes for hydrogen evolution were investigated. Results showed that the electrocatalytic activities of TiO2/Ni–Mo and Ti–SiO2/Ni–Mo composite electrodes for hydrogen evolution reached the optimal value when the concentration of particles was 4 g/L and 2 g/L respectively. The electrocatalytic activities of TiO2/Ni–Mo and Ti–SiO2/Ni–Mo composite electrodes were greater than that of Ni–Mo alloy electrode, and the Ti–SiO2/Ni–Mo composite electrode showed the best electrocatalytic activity.