One-step nanoporous structure formation using NiO nanoparticles: Pore size control and pore size dependence of hydrogen evolution reaction

A nanoporous nickel with tunable pore size was prepared with a one-step annealing method using nickel oxide nanoparticles. The in situ formation of nanoporous structures occurs by the sequential cooperation of reduction of nickel oxide on the surface and anisotropic reconstruction of reduced nickel under a hydrogen reductive atmosphere. The nickel oxide skeleton inside the nanoporous structures plays an important role to suppress coarsening of nanoporous structures. The resulting tunable nanoporous nickel provides good understanding of pore size dependence in the hydrogen evolution reaction in electrolysis of water.