Evaluation of photocatalytic properties of TiO₂/g-C₃N₄ core-shell hybrid catalyst supported on Sr₄Al₁₄O₂₅:eu,dy phosphor

TiO₂/g-C₃N₄ hybrid compounds were supported as core-shell catalyst on Sr₄Al₁₄O₂₅:Eu,Dy phosphor powder by a 2-step hydrothermal and solvothermal self-assembly method. Surface and chemical characterizations confirmed that the phosphor substrate and the hybrid catalysts co-existed as a multi-composite material. Where nano spherical TiO₂ particles were dominant as core/shell catalyst. Diffuse reflectance spectra were shifted toward the visible light region (400 nm to 600 nm) in composites with g-C₃N₄ as shell-catalyst. X-ray photon spectroscopy (XPS) confirmed the chemical integrity and binding of g-C₃N₄ on phosphor/TiO₂ material. When g-C₃N₄ was coated as shell-catalyst on phosphor/TiO₂, superior photocatalytic performances of above 90% efficiency were obtained in comparison to where TiO₂ was coated as shell-catalyst under both ultraviolet and visible light illumination. Thus, g-C₃N₄ is more active as shell-catalyst owing to its lower band gap of 2.7 eV than core TiO₂ (3.2 eV).