Green synthesis of luminescent La‐MOF nanoparticle from waste poly(ethylene terephthalate) for high‐performance in Fe(III) detection

Abstract Developing luminescent metal–organic frameworks (MOFs) capable of high‐efficiency Fe 3+ sensing has aroused great attraction in the fields of biology, chemistry, etc. However, previous solvothermal methods are limited by organic solvent usage, time consuming, high pressure, and high‐energy consumption. Herein, we propose the waste‐to‐MOF strategy towards the scale‐up production of La‐MOF nanoparticles through the ball milling of recycled poly(ethylene terephthalate) (PET) bottles and La(NO 3 ) 3 ⋅6H 2 O. PET goes on alkaline hydrolysis to form 1,4‐benzenedicarboxylic acid sodium salt (Na 2 BDC) and ethylene glycol by ball milling. Subsequently, BDC reacts with La 3+ to form La‐MOF. The as‐prepared La‐MOF crystal nanoparticles possess a rod‐like morphology with the size of few hundred nanometers. Additionally, La‐MOF nanoparticles display high selectivity and sensitivity for Fe 3+ detection. The quenching constant and limit of detection are 5.29 × 10 3 (mol·L −1 ) −1 and 0.147 μmol·L −1 , respectively, thus surpassing many advanced Fe 3+ sensors. According to the result of density functional theory, the high Fe 3+ detection performance of La‐MOF is related to the complexing of Fe 3+ with La‐MOF, which leads to the gradual dissociation of the coordination bond between terephthalic acid and La 3+ . It is anticipated that the mechanochemistry milling‐based waste‐to‐MOF strategy provides a new platform for the massive production of functional MOFs in a green manner.