Rod-like nano-composite of inorganic nanowires encapsulated by mesoporous silica solid

A novel rod-like praseodymium-containing inorganic nanowire encapsulated by mesoporous silica, was synthesized via a self-assembly method. The specific surface area of the composite was 1198m²g^− 1. The nanowires with 4-5 nm in diameter and 100 nm in length were encapsulated at the center of mesoporous solid showed by TEM images. The quantum size effects of the sample can be noted. The controversial absorption band at 960 cm^− 1 in Fourier-transform infrared (FT-IR) spectra was proved to be not the evidence of the introduction of heteroatom. On the basis of the absorption spectra and select area electron diffraction (SEAD) pattern, the nano-composite was known as an amorphous phase containing praseodymium element, in which the praseodymium was trivalent. The absorption spectra indicated the 4f² electronic configuration of Pr³⁺ ions. Four energy bands were attributed to the transitions from the ground state ³H₄ to the excited levels ³P₂, ³P₁, ³P₀ and ¹D₂, respectively.