Synthesis of 2D Rare earth elements oxide nano-sheets from Nd-Fe-B magnets

With rising global demand for rare earth elements (REEs) in a range of emerging clean energy technologies such as hybrid electric vehicles, and the uncertainty in their supply, REEs are now under severe risk. The development of new technologies for the recovery of REEs from waste and also replacing the conventional resources with the alternative renewable sources is urgently needed. Currently, Nd-Fe-B magnets are known as one of the most extensively used types of REE magnets which can be used as a potentially valuable and rich source of REEs (i.e., Nd, Pr and Dy). In the present paper, using REEs (i.e., Nd, Pr and Dy) recovered from the end-of-life Nd-Fe-B magnets, we applied homogeneous precipitation technique at low temperature and synthesised REEs (i.e., Nd, Pr and Dy) hydrate oxalate which was then utilised as a precursor for the synthesis of REO nano-sheets. FE-SEM and TEM images showed that the synthesised REO nano-sheets were in the dimension of ∼1μm×0.5μm×17 nm made from nano-particles. From X-ray diffraction spectrum, several strong peaks assigning to the cubic phase of Nd2O3 and small peaks corresponding to cubic phases of NdPrO3 and Pr2O3 were detected. This paper confirms the feasibility of transforming waste materials such as end-of-life Nd-Fe-B magnets into valuable nano-structured products through a simple pathway.