Preparation of Ag-TiO2/Sr4Al14O25:Eu2+,Dy3+ Photocatalyst on Phosphor Beads and Its Photoreaction Characteristics

Abstract

Long-lasting Sr4Al14O25:Eu2+,Dy3+ phosphor beads were prepared with inorganic sodium silicate binders and coated to support Ag-doped TiO2 catalyst by the sol–gel coating method. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy confirmed that Ag and TiO2 were loaded on the bead surface. Photocatalytic degradation of toluene volatile organic compound was evaluated under ultraviolet and visible light through 410 nm filters. The photocatalyst/phosphor beads of Ag-TiO2/Sr4Al14O25:Eu2+,Dy3+ decorated with 0.035 M Ag in N2 and N2-H2 atmospheres exhibited higher photocatalytic efficiencies compared with beads heat treated in air. A low amount of Ag impregnation and the reducing atmosphere of N2/N2-H2 were beneficial for enhancing photocatalytic efficiency because Ag-doping in TiO2 imparted low energy levels for visible light sensitization. The synthesized powder-free beads possess compressive strength for possible applications, and easy recovery of the photocatalysts is beneficial for preventing any secondary pollution of nano-powders.

Nano Metal-Containing Photocatalysts for the Removal of Volatile Organic Compounds: Doping, Performance, and Mechanisms

“…For example, N-doped TiO 2 /WO 3 has excellent catalytic performance under visible light [70]. In addition, some noble metal elements like Ag may also enhance the light absorption of photocatalysts by surface plasmon resonance [72]. The doping of some transition metal and non-metal elements, such as V, Zr, Cr, Mn, N, etc., may introduce vacancies or defects in the catalyst crystals, and these vacancies or defects often perform as highly active reaction sites in reactions [52].…”

“…As for the problem of the recovery of nanoparticle photocatalysts, Eun S.R. et al [72] developed Ag-TiO 2 /Sr 4 Al 14 O 25 : Eu 2+ , Dy 3+ phosphor beads' nano photocatalysts for the degradation of toluene by UV/Vis via a sol-gel coating method. The photocatalyst had higher catalytic activity due to the doping of Ag element and was conducive to the recycling of nano materials to prevent secondary pollution.…”

Luminescent Materials Based on Aluminates: A Review

“…[ 201 ] It was also claimed that it could be used as a photocatalyst. [ 202 ] Degradation of toxic materials [ 203 ] such as organic dyes [ 204 ] to some harmless form can be achieved using photocatalysis with LLP materials. Carlos et al [ 205 ] found enhancement in photocatalytic activity due to Bi 3+ codoping.…”

Sonochemical preparation and characterization of Sm‐doped GO/KSrPO4 nanocomposite photocatalyst for degradation of methylene blue dye

“…Photocatalytic activity of the prepared SAOs was higher than TiO 2 photocatalyst due to higher photosensitivity and lower band‐gap of the SAOs compared to TiO 2 . Thus, several phosphors have been used as effective photocatalysts for degradation of different types of pollutants (Eun et al, 2021; Li et al, 2012; Ma et al, 2013; Naorem et al, 2020). In fact, the phosphors are known as luminescence‐assisted photocatalysts which use their long afterglow as a light source to carry out the photocatalytic reaction (Li et al, 2012).…”