Surface modification of MAl_2O_4:Eu~(2+)Dy~(3+) (M = Sr, Ca, Ba) phosphors to enhance water resistance by combustion method

摘要

A facile combustion method was introduced into surface modification of MAl_2O_4:Eu~(2+),Dy~(3+) (M=Sr, Ca, Ba) phosphors to improve their water resistance. X-ray diffraction (XRD), X-ray photoelectron spec-troscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), pH measurements and photoluminescence (PL) spectrophotometry were used to characterize the phosphors before and after modification, respectively. Experimental results showed that compact layer of MAl_2B_2O_7 (M = Sr, Ca, Ba) substance was formed on the surface of aluminate phosphors by direct chemical reaction between aluminate and boracic acid. MAl_2B_2O_7 (M - Sr, Ca, Ba) substance is chemically stable in water and could improve water resistance of aluminate phosphors effectively with little influence of luminescence property. It was considered that the versatility of combustion method for surface modification of aluminate phosphors has been confirmed.