Reductive hydrothermal synthesis of La(OH)3:Tb3+ nanorods as a new green emitting phosphor

A reductive hydrothermal process with use of hydrazine hydrate as a protecting agent is proposed to synthesize La(OH)3:Tb3+ (Tb mol% = 0, 1, 5, 10, and 20) nanorods. The oxidation of Tb3+−Tb4+ was effectively prevented in the presence of hydrazine hydrate; hence the La(OH)3:Tb3+ nanorods exhibited much stronger green photoluminescence than the product prepared by the normal hydrothermal process. X-ray diffraction and transmission electron microscopy were employed to characterize the products, the results of which revealed that all the products were one-dimensional rod-like nanostructures of hexagonal structure (∼20 nm in diameter). The reductive hydrothermal process is desirable for the synthesis of other efficient Tb3+ doped nanophosphers.