Microwave approach for the synthesis of rhabdophane-type lanthanide orthophosphate (Ln=La,Ce,Nd,Sm,Eu,Gd and Tb) nanorods under solvothermal conditions

摘要

Rhabdophane-type hexagonal lanthanide orthophosphate,LnPO_4centre dotnH_2O (Ln=La,Ce,Nd,Sm,Eu,Gd and Tb,n=0 to 0.6),and body-centered tetragonal ErPO_4centre dotH_2O nanowiresanorods have been successfully synthesized in high yield (>95%) by simple microwave heating of an aqueous solution of Ln(III) nitrate and NH_4H_2PO_4 in the pH range 1.8-2.2.The reaction was conducted in a simple domestic microwave oven.The structure,morphology,composition and physical properties of the as-prepared products have been characterized by powder X-ray diffraction,low resolution transmission electron microscopy,high resolution transmission electron microscopy,selected area electron diffraction,thermogravimetric analysis,differential scanning calorimetry,infrared spectroscopy,Raman spectroscopy,X-ray photoelectron spectroscopy,and photoluminescence spectroscopy.The length and width of the resulting lanthanide orthophosphate nanowiresanorods are in the range 70-2200 nm and 6-130 nm,respectively.A possible mechanism for the formation of LnPO_4centre dotnH_2O nanowiresanorods is briefly discussed.