Nickel hydroxide ultrathin nanosheets as building blocks for electrochemically active layers

Abstract

Layered nickel hydroxides (LNHs), intercalated with lactate and nitrate anions, were synthesised using controlled precipitation and anion exchange methods. The present study reports a novel approach for the delamination of LNHs in water into nickel hydroxide nanosheets. The thickness of a single nanosheet varied between 0.7 and 1.0 nm with a lateral dimension between 50 and 80 nm. The nanosheets formed colloidal solutions or gels, retained the original hydroxide structure of LNHs, and were stable for weeks. The nanosheets were re-assembled into large-scale, well-oriented films with adjustable thickness using drop casting and spin coating techniques. The prepared nanostructured films were electrochemically active with stable and reproducible charge–discharge properties in an alkaline electrolyte. These results suggest that the nickel hydroxide nanosheets, prepared by the present methods, have potential as building blocks in the design of nanocomposite materials for energy applications.