Mesoporous hollow Zn₂SiO₄:Mn²⁺ nanospheres: The study of photoluminescence and adsorption properties

Graphical abstract: Mesoporous hollow structure of Zn₂SiO₄:Mn²⁺ phosphors. - Highlights: • Mesoporous hollow Zn₂SiO₄:Mn²⁺ nanospheres are prepared via the layer-by-layer technique. • The Zn₂SiO₄:Mn²⁺ nanospheres exhibit better adsorption capabilities of Pb²⁺, Fe³⁺ than Cd²⁺. • The Zn₂SiO₄:Mn²⁺ nanospheres exhibit strong green emission around 524 nm. • With the increase of doped Mn²⁺ concentration, the emission peak shows a red-shift. - Abstract: Mesoporous hollow Zn₂SiO₄:Mn²⁺ nanospheres were prepared via the layer-by-layer technique using CTAB as surfactant. The structures/microstructures and morphologies of the as-synthesized phosphors were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope and N₂ adsorption–desorption porosimetry. The adsorption capacity to remove toxic metal ions in water was tested and the results showed that the Zn₂SiO₄:Mn²⁺ nanospheres exhibited better adsorption capabilities of Pb²⁺, Fe³⁺ than Cd²⁺. Moreover, the as-obtained hollow Zn₂SiO₄:Mn²⁺ phosphors exhibited strong green emission around 524 nm at room temperature. When the atomic ratio of Zn to Mn was 97:3, the emission intensity of Zn₂SiO₄:Mn²⁺ phosphor was about 1.2 times that of commercial phosphors. Furthermore, with the increase of doped Mn²⁺ concentration, the emission peak showed a red-shift