Enhanced photocatalytic decomposition of methylene blue and toluene gas with hydrothermally coated TiO2-supported on Ag–CaAl2O4:Eu2+, Nd3+ long-lasting phosphor.

Titanium dioxide was coated by hydrothermal reaction on the surface of CaAl₂O₄:Eu²⁺,Nd³⁺ long-lasting phosphor beads on which a silver noble metal was impregnated to enhance photocatalytic reactivity. The phosphor composite as a TiO₂ supporter was fabricated in the form of beads for convenient applications. Silver was impregnated on the CaAl₂O₄:Eu²⁺,Nd³⁺ long-lasting phosphor using a silver nitrate aqueous solution prior to TiO₂ coating process. The morphological and compositional characteristics of the TiO₂ coated phosphor composite materials were measured using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectrometer (XPS). The photocatalytic properties of the TiO₂ coated phosphor composite materials were analyzed through decompositions of both methylene blue dye solution and toluene gas under ultraviolet and visible light irradiation. Through measuring the variation of photocatalytic reaction with different Ag concentrations, 0.035 M Ag-impregnated TiO₂/CaAl₂O₄:Eu²⁺,Nd³⁺ phosphor composite showed the best photocatalysis efficiency under UV and visible light illumination. [ABSTRACT FROM AUTHOR]