Recycling Lead (II) Management in Metal Organic Framework-Perovskite Luminescent Composites

Colloidal lead halide perovskites face challenges in practical optoelectronic applications due to the toxicity of lead (II). To overcome this issue, a novel approach using metal-organic frameworks (MOFs) for recycling lead (II) management in perovskite materials, is developed. Through surface-functionalization of MOF-808 and pH tuning, the MOF achieves recyclable adsorption-desorption of lead (II), confining the lead source within the MOF-808 template or the perovskites. This controllable transformation between lead (II) chelation and perovskites prevents lead (II) leakage. Additionally, separated lead (II) ions from decomposed perovskite can be adsorbed by MOF-808, facilitating recycling. The resulting MOF-808-EDTA@CsPbBr3 composite exhibits comparable optical performance to pure CsPbBr3 powder, but with improved stabilities, effectively preventing lead (II) leakage. Hierarchical desorption of lead (II) in the MOF-808-EDTA@Pb2+ complex enables reversible on/off fluorescence signal switching. Detached lead (II) from decomposed MOF-808-EDTA@CsPbBr3 composite can be re-adsorbed by MOF-808-EDTA, enabling the construction of CsPbBr3 nanocrystals in a new cycle. This approach is economically attractive and environmentally friendly. This study addresses the challenge of lead (II) leakage and offers the potential for optical anti-counterfeiting in perovskite materials with a sustainable approach.