Synthesis and self-assembly of ultrathin Ni(x)Fe(1-x)(OH)2 nanodiscs via a wet-chemistry method

Self-assembled ultrathin Ni(x)Fe(1-x)(OH)2 nanodiscs have been synthesized by using a wet-chemistry method. The uniformity and the assembly of Ni(x)Fe(1-x)(OH)2 nanostructures are sensitive to the iron ion concentration in the precursor. An optimum iron concentration of 10% results in the formation of uniform ultrathin Ni(x)Fe(1-x)(OH)2 nanodiscs with a typical side length of 50 nm and a thickness of 10 nm. They are also self-assembled by connecting their (001) facets with in-plane orientation and form a chain-like microstructure. Lattice relaxation is present within several atomic layers at the interfaces between two adjacent nanodiscs, which introduces about 6 degrees misalignment of these nanocrystals. Analytical electron microscopy analysis reveals that the iron additive atoms distribute uniformly in the nanodiscs and they are substitution atoms of Ni atoms. It has been found that the iron species is critical to the formation and assembly of the hexagonal nanodiscs.