Du Jingjing,Xie Shaowen,Li Na,Xu Jianxiong,Xu Lijian
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.
ABSTRACT In order to reduce energy consumption in water electrolysis, it is of great importance to design active and stable electrocatalysts for hydrogen evolution reaction (HER) in alkaline solution, especially based on earth-abundant metal. Here we integrate carbon nanotubes (CNTs) and Ni-Ni(OH) 2 heterostructure multifunctional components to design a self-supported 3D CNTs-Ni-Ni(OH) 2 catalyst for HER by composite deposition and subsequent in-situ oxidation . In alkaline solution, this designed CNTs-Ni-Ni(OH) 2 catalyst exhibits 0 mV onset overpotential, and overpotentials of 65 mV and 109 mV at 10 and 50 mA/cm 2 respectively. Electrochemical measurements, characterizations, and simulation results attribute the outstanding performance to the incorporation of CNTs and heterostructure . CNTs induce the formation 3D catalytic surface, enhance electrochemical active surface area , and more importantly weaken the adsorption of H. Moreover, the formation of heterostructure, especially reversible Ni(OH) 2 , supplies active sites and adjusts the adsorption strength of H atom to an optimal value. CNTs and heterostructure synergistically facilitate water adsorption, promote water dissociation, and accelerate H 2 desorption. Significantly, integration of multifunctional components supplies a distinct strategy for development of cost-effective electrocatalyst with outstanding performance.