Fabrication of two-phase Ca²⁺-doped LaVO₄:Eu³⁺ structures: morphology modification, tunable optical performance and detection of Fe³⁺ ions with high sensitivity

Two-phase Ca²⁺-doped LaVO₄:Eu³⁺ nanocrystals were prepared through a hydrothermal method with the help of SOD CITR and EDTA surfactants. The phase and morphology of the products were characterized by XRD and TEM, and the fluorescence performances were also recorded. The results indicated that Ca²⁺ ions were doped into the LaVO₄:Eu³⁺ host lattice, impeding the aggregation of the nanocrystals and enhancing the luminescence intensity. The morphology transformation process and luminescence enhancement were systematacially investigated. The fluorescence intensity of the two selected samples could be completely quenched by Fe³⁺ ions without the disturbance of other ions, with the mechanism being due to the adsorption of Fe³⁺ ions onto the grains and a subsequent energy transfer from Eu³⁺ to Fe³⁺. Therefore, the present two Ca²⁺-doped LaVO₄:Eu³⁺ samples can be applied as appropriate candidates for detecting Fe³⁺ ions with agility and sensitivity in aqueous solution.