Hydrothermal synthesis of novel Ni microflowers with enhanced ferromagnetic properties

Novel nickel microflowers assembled with many thin nanoplates were synthesised through a simple hydrothermal method using sodium hypophosphite as a green reducing reagent. Sodium tartrate served as a complexing reagent and cetyltrimethylammonium bromide (CTAB) was used as a surfactant. It was found that the amount of sodium hydroxide played a key role in determining both the shape and to further the self‐assembly process of nickel flowers. Such a flower‐like nickel microstructure shows a great enhancement of the ferromagnetic properties with a coercivity of 308.7 Oe, which may be ascribed to the distinctive two‐dimensional (2D) anisotropic structure of the nanoplates and the final hierarchically flower‐like shape. This work presents a preferred approach to fabricate high‐quality magnetic nickel microflowers which have potential applications in electrochemical devices, magnetic sensors, and catalytic agents.