Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2310.12998

Combined Experimental and Theoretical Studies on Iodine Capture of Zr-based Metal-Organic Frameworks: Effect of N-functionalization and Adsorption Mechanism

Jie Liang·Haoyi Tan·Jiaomei Liu·Huizhao Qi·Xin Li·Liu Wu·Xiangfei Xue·Guangcun Shan
View original source ↗Read source document ↗Export metadata ↓

Abstract

The potential leakage of nuclear waste, especially radioiodine, is a major safety concerning issue around the world. To remove radioiodine from nuclear waste efficiently, there is an urgent demand for adsorbents that possess both high stability and strong adsorption affinity for environmental remediation. Herein, two Zr-based metal-organic frameworks (Zr-MOFs) and their N-functionalized analogues have been synthesized and researched for iodine adsorption in both vapours and solutions. It was found that Zr-MOFs with N-enriched ligands (e.g., pyridine and amino) exhibited the faster iodine adsorption rate and the higher iodine uptake amount (e.g., reaching adsorption equilibrium within 4 hours with the removal rate of above 85% for iodine solution adsorption) than their unfunctionalized counterparts (UiO-66 and UiO-67). The critical role played by N-enriched groups in enhancing iodine adsorption has been revealed through versatile model fittings, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy characterizations, as well as density functional theory (DFT) calculations. Compared to those in amino-group, the N-atoms in pyridine-groups showed a deeper affinity towards iodine molecules. Remarkably, the N-enriched UiOs adsorbents also exhibited good recyclability, especially UiO-66-PYDC and UiO-67-NH2 could maintain the removal efficiency of 89.05% and 85.49% after four adsorption-desorption recycling tests. With the strong iodine uptake affinity and outstanding regeneration performance, this work has systematically investigated the impact of N-functionalization on the enhanced performance for iodine capture by using the N-enriched UiO MOFs as promising adsorbents, providing an insightful guideline into the physical chemistry of adsorption mechanism behind the radioiodine capture.

Explore related subjects

cond-mat.mtrl-sciphysics.chem-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jie Liang, Haoyi Tan, Jiaomei Liu, Huizhao Qi, Xin Li, Liu Wu, Xiangfei Xue, Guangcun Shan. 2023-10-05. Combined Experimental and Theoretical Studies on Iodine Capture of Zr-based Metal-Organic Frameworks: Effect of N-functionalization and Adsorption Mechanism. https://doi.org/10.1016/j.mtsust.2023.100574

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Incommensurate structural and magnetic modulations in potassium-rich cryptomelane, K$_x$Mn$_8$O$_{16}$ ($x\approx1.45$)

Cryptomelane is a hollandite-like material consisting of K$^+$ cations in an $α$-MnO$_2$ tunnel-like crystallographic motif. Cryptomelane with stoichiometry K$_x$Mn$_8$O$_{16}$ ($x\approx1.45$) has been synthesized and its magnetic properties investigated using variable-temperature magnetic susceptibility, heat capacity, and neutron powder diffraction. Three distinct transitions at $T_1=184$\,K, $T_2=54.5$\,K, and $T_3=24$\,K are observed. At $T_1$ there is a subtle tetragonal$\rightarrow$monoclinic transition associated with emergence of a set of non-magnetic superstructure peaks indexable to a $\vec{k}_\mathrm{struc}\approx0.74\vec{c^*}$ incommensurate modulation parallel to the $α$-MnO$_2$ tunnels. Our findings are consistent with a relation previously reported in titanate hollandites, that $x\approx2|\vec{k}_\mathrm{struc}|$. Magnetic Bragg peaks emerge below $T_2=54.5$\,K, and their positions indicate an incommensurate modulated magnetic structure. The model consistent with the data is a dual-$\vec{k}_\mathrm{mag}$ structure with a ferromagnetic $|\vec{k}_\mathrm{mag}|=0$ component and an incommensurate $\vec{k}_\mathrm{mag}\approx0.37\vec{c^*}$, with the latter most likely to be helical. The period of oscillation of the incommensurate magnetic component is in line with predictions based on a Heisenberg spin Hamiltonian [Mandal \textit{et al}. Phys. Rev. B 90, 104420 (2014)]. Below $T_3=24$\,K, there is a magnetic transition, which gives rise to a different set of magnetic Bragg peaks indicative of a highly complex magnetic structure.

cond-mat.mtrl-sci↗
arXiv2026

An anisotropic functional for two-dimensional material systems

Density function theory is the workhorse of modern electronic structure theory. However, its accuracy in practical calculations is limited by the choice of the exchange-correlation potential. In this respect, two-dimensional materials pose a special challenge, as all these materials and their heterostructures have a crucial similarity. The underlying atomic structures are strongly spatially inhomogeneous, implying that current exchange-correlation functionals, that in almost all cases are isotropic, are ill-prepared for an accurate description. We present an anisotropic screened-exchange potential, that remedies this problem and reproduces the band-gap of 2D materials as well as the piecewise linearity of the total energy with fractional occupation number.

cond-mat.mtrl-sci↗
arXiv2026

Thermally-driven reorientation of the Néel vector in altermagnetic MnTe

Altermagnets are novel magnetic systems that possess a spin-polarized electronic band structure without a net magnetic moment, making them promising for device applications. Hexagonal MnTe, a prototypical altermagnet, arguably exhibits the most properties consistent with theoretical predictions, including an anomalous Hall effect despite a vanishing net magnetization, and altermagnetinduced electronic band splitting. However, fundamental questions remain, including why some effects only appear significantly below the magnetic ordering temperature. Here, we resolve this discrepancy by revealing a reorientation of the Néel vector in single-crystalline MnTe. The Néel vector points 30° from the a-axis at low $T$, before aligning directly with the a-axis around $T\simeq 260$ K. We attribute this to single-ion anisotropy, which depends on temperature-dependent lattice parameters. We obtained these results using muon-spin spectroscopy, magnetization measurements, and X-ray diffraction; we show that the findings are consistent with neutron diffraction. Manipulating this effect, for example through strain, could unlock sensitive electronic detection schemes for external stimuli, paving the way for functional altermagnetic devices.

cond-mat.mtrl-sci↗