Boyang Wang,Yuankun Ren,Xiaohan Wei,Wei Yang,Haoming Su,Yu Liu,Jiaqi Liang,Xiyu Li
Lanthanide-doped fluorapatite (FAp:Ln3+) upconversion luminescence (UCL) probes exhibit good biocompatibility but suffer from low quantum yields under near-infrared (NIR) excitation. Here, we propose a universal MoO42− doping strategy that achieves 74-fold green UCL enhancement in FAp:Yb/Er/Mo (FYEM) under 980 nm excitation (quantum yield: 0.004% at 50 W cm−2). Remarkably, stable Ln3+/MoO42− dimers induce 4d–4f orbital hybridization, as validated by density functional theory (DFT) and X-ray photoelectron spectroscopy (XPS). This mechanism extends to self-sensitized systems: FAp:Er/Mo (FEM) achieves 156-fold UCL enhancement under 980 nm excitation, while FAp:Nd/Mo (FNM) integrates 84-fold UCL amplification with photothermal synergy (ΔT = 53.5 °C). Critically, the optimized FYEM material enables dual-mode imaging, with 808/980 nm excitation UCL and NIR-II downconversion luminescence for deep-tissue imaging, besides outstanding thermal sensitivity (SA = 1.04% K−1@323 K). This work establishes a biocompatible, multi-wavelength platform for deep-tissue diagnostics, photothermal therapy, and multimodal sensing and imaging.
The development of non-iridium-based oxygen evolution reaction (OER) catalysts is crucial for proton exchange membrane water electrolysis (PEMWE), but hydrogen production remains a great challenge because of sluggish OER kinetics and severe catalyst dissolution. Here, we present a 4 f -induced covalent polarity modulation strategy for the construction of 4 f -orbital-modified RuO 2 (4 f -RuO 2 ) nanocatalysts with tunable Ru–O polarity. We find that the OER activity of 4 f -RuO 2 shows a volcano shape as a function of the polarity of Ru–O bond. Consequently, the best 4 f -Nd-RuO 2 catalyst possesses an ultra-low overpotential of 214 mV at 10 mA cm −2 and robust electrochemical stability in 0.1 M HClO 4 . Theoretical calculations coupled with in situ synchrotron infrared and X-ray absorption spectroscopy analyses reveal that the modulation of Ru–O polarity in RuO 2 by the valence f − p − d gradient orbital coupling can modify the adsorption energy of the reaction intermediates and suppress the participation of lattice oxygen to avoid over-oxidation of Ru, which can thus serve as an effective descriptor for fine tuning the activity and durability of acidic OER nanocatalysts.
Min Chen,Zhengli Liang,Xiaoxiao Wang,Jiehua Li,Xingguo Chen,Xingxing Jiang,Zheshuai Lin,Zhen Ma,Hongming Liu
A series of lanthanide-containing water-resistant nitrates, namely RE(OH)2NO3 (RE = Tb(1), Dy(2), Ho(3), and Er(4)), was obtained through the hydrothermal process. As possible nonlinear optical materials, they feature a layered isomorph composed of an [REO3(OH)6] polyhedron and an [NO3] triangle, and the synergistic arrangement of the [REO3(OH)6] and [NO3] groups in their structures leads to their obvious second-order nonlinear optical effect. Nevertheless, the unique optical absorption caused by the electronic transitions on 4f–4f orbitals of lanthanides results in their second harmonic generation responses of different strengths, with 1 exhibiting 5.07 times that of KDP, but 2–4 showing less than half of KDP. In addition, 1 possesses an outstanding water-resistant capacity and a transparent cut-off edge around 300 nm, foreshadowing its potential value as a nonlinear optical crystal. Moreover, 1 is found to emit characteristic green fluorescence due to the typical 5D4 → 7F5 transitions of the excited Tb3+ ions