Synthesis of luminescent terbium-thenoyltriflouroacetone MOF nanorods for green laser application

TL;DR

This study synthesized luminescent terbium-based MOF nanorods with controlled morphology and enhanced green emission for potential laser applications, demonstrating high energy transfer efficiency and improved luminescent intensity at higher terbium concentrations.

Contribution

It presents a simple room-temperature synthesis of terbium-thenoyltriflouroacetone MOF nanorods with detailed structural and luminescent characterization, highlighting their suitability for green laser applications.

Findings

Nanorods with 170 nm diameter and 2 μm length were synthesized.

Luminescence intensity increased 3.5 times at 50% Tb doping.

Energy transfer efficiency from ligand to terbium was above 0.98.

Abstract

In this study, a thenoyltriflouroacetone ligand (TTA) with a Tb3+ MOF was synthesized (Tb=10 and 50% mol) and its structural and luminescent properties were analyzed. The metalorganic compound was generated in a simple one-pot reaction from terbium nitrate and 2-thenoyltrifluoroacetone precursors at room temperature. By means of FTIR, it was confirmed the presence of carbon groups, which made possible the terbium ion chelation, and also the Tb-O bonds vibration modes. HNMR results confirm that the complex with 10% mol of Tb3+ contains three coordinates molecules of TTA and two waters molecules. The powders exhibit rod-like morphology with size about 170 nm of diameter and a length about 2 {\mu}m, the rod-like nature of powders was confirmed by SEM and TEM analyses. By XRD it was concluded that at higher terbium concentration (TTA-50Tb sample) higher the crystallite size and crystallinity, in fact the TTA-10Tb sample shows a partial-amorphous nature. By photoluminescence analyses, the 5D4-7FJ (J=3, 4, 5 and 6) emissions were recorded for both synthesized samples ({\lambda}exc=376 nm). Furthermore, it was observed that the emission intensity was enhanced in a factor of 3.5 for the TTA-50Tb. The energy transfer efficiency from TTA to Tb3+ (antenna effect) was 0.984 for TTA-10Tb and 0.993 for TTA-50Tb. Decay time analyses indicate effective lifetime of 1.45 and 1.60ms for the samples doped at 10 and 50%, respectively, indicating that the forbidden transition rules are stronger at higher crystallinity. The integrated intensities of the 5D4 - 7F5 (green at 541 nm) and 5D4 - 7F6 (blue at 486 nm) emissions and their intensity ratios IG/IB upon 376 nm excitation have been evaluated for TTA-10Tb andTTA-50Tb samples.