Eco-friendly strategy for synthesizing europium-complex-based hybrid materials using bifunctional hydroxyapatite

Synthesizing lanthanide complexes and their hybrid materials often involves the utilization of hazard base reagents to neutralize the protons generated in coordination reactions. Here, we propose for the first time a green and facile route to synthesize europium-complex-based hybrid materials by using micrometer-sized hydroxyapatite (HAP). Simultaneous formations of the europium complex and monetite took place after the reaction. Not only did HAP function as an eco-friendly alkaline reagent, but it also acted as a matrix to disperse the europium complexes. The quantum yield and lifetime of the as-synthesized hybrid materials are comparable to that of pure europium complex prepared by using traditional base reagents. Furthermore, versatile applications of the hybrid materials are also demonstrated in our proof-of-concept experiments, including bone tissue engineering, luminescent toys, and portable luminescent chalks. Notably, the proposed eco-friendly strategy is also applicable to other types of lanthanide-complexes-based hybrid materials.