Core/Shell Nitrogen-Doped TiO2@SiO2 Nano-Catalyst as an Additive in Photocatalytic Paint for Gaseous Acetaldehyde Decomposition

A nitrogen-doped TiO2@SiO2 core/shell nano-photocatalyst (N-TiO2@SiO2) was used as an
additive in photocatalytic paint and applied for the photocatalytic degradation of gaseous acetaldehyde
under light-emitting diode (LED) visible light irradiation. N-TiO2 was synthesised via the solvothermal
method and then encapsulated by SiO2 via the sol-gel method. The incorporation of the
N atom into the TiO2 structure was observed by X-ray photoelectron spectroscopy. The N-TiO2@SiO2
core/shell structure was determined by TEM images. The photodegradation of gaseous acetaldehyde
using the prepared N-TiO2@SiO2 photocatalytic paint was examined in a closed chamber under
LED light irradiation. The photodegradation of acetaldehyde by N-TiO2@SiO2 photocatalytic
paint (31%) was significantly higher than that of TiO2 paint (5%) and N-TiO2 paint (20%) within 16
h. The chemical resistance and adhesion ability of N-TiO2@SiO2 photocatalytic paint were investigated
following Thai Industrial Standards (TIS) no. 2321 and standard test methods for rating adhesion
by tape test (ASTM D 3359-22). The N-TiO2@SiO2 paint showed good acid and alkali resistance,
as well as high adhesion ability comparable with commercial paint (without a photocatalyst).