Synthesis and characterization of macroporous europium-doped Ca12Al14O33 (C12A7:Eu3+) and its application in metal ion detection

Abstract

Macroporous europium-doped Ca₁₂Al₁₄O₃₃ (C12A7:Eu³⁺) was prepared via a sol–gel method followed by heat-treatment, and the crystal structure, luminescence performance and metal ion luminescence sensing of C12A7:Eu³⁺ were investigated and evaluated in detail. The process of the sol–gel method and heat-treatment promotes the formation of a single mayenite phase C12A7:Eu³⁺, and the Eu³⁺ ions are incorporated into the crystal lattice and replace the position of the Ca²⁺ ions without destroying the lattice structure of C12A7. The interconnected macropores not only increase the lighting area but also reduce the concentration quenching effect, leading to a significant enhance of luminescence intensity. The resultant macroporous C12A7:Eu³⁺ can be used as a luminescence performance sensor and displays the potential practical application for metal ion detection. The macroporous C12A7:Eu³⁺ sensor has a good response to Pb²⁺ ions, whose linear equation between concentration (C_Pb) and luminescence intensity (F) of (F₀ − F)/F₀ = 1.412 + 0.3428 log₁₀(C_Pb) can be obtained.