Controlled fabrication and property studies of nickel hydroxide and nickel oxidenanostructures

In this article, different Ni(OH)2 nanostructures have been synthesized through a facile template- and surfactant-free approach. By adding additives, changing the nickel source or choosing different solvents, nickel hydroxide can be controllably synthesized from β-Ni(OH)2 nanodisks to hierarchical β-Ni(OH)2 superstructures assembled by nanoplate building blocks. This approach is very easy and only 2–3 chemicals and no template or surfactant are used. The growth rate has the most influence on the formation of β-Ni(OH)2 nanostructures with different assembling modes. The obtained β-Ni(OH)2 samples show different electrochemical behaviors with different superstructures. Furthermore, cubic nickel oxide (NiO) crystals with nanopores have also been successfully obtained by thermal decomposition of the as-synthesized β-Ni(OH)2 in air. The magnetic parameters of these NiO nanostructures are different and related to the change of the superstructures.