Radiocesium remediation is desirable for ecological protection, human health and sustainable development of nuclear energy. Effective capture of Cs
from acidic solutions is still challenging, mainly ...due to the low stability of the adsorbing materials and the competitive adsorption of protons. Herein, the rapid and highly selective capture of Cs
from strongly acidic solutions is achieved by a robust K
-directed layered metal sulfide KInSnS
(InSnS-1) that exhibits excellent acid and radiation resistance. InSnS-1 possesses high adsorption capacity for Cs
and can serve as the stationary phase in ion exchange columns to effectively remove Cs
from neutral and acidic solutions. The adsorption of Cs
and H
O
is monitored by single-crystal structure analysis, and thus the underlying mechanism of selective Cs
capture from acidic solutions is elucidated at the molecular level.
Zero-dimensional (0D) metal halides with solid-state luminescence switching (SSLS) have attracted attention as sensors and luminescent anticounterfeiting. Herein, selective solvent molecule response ...and accordingly luminescence switching were discovered in 0D EtPPh32SbCl5 (1, EtPPh3 = ethyltriphenylphosphonium). More than a dozen kinds of solvent molecules have been tested to find out the selection rule for molecule absorption in 1, which is demonstrated to be the size effect of guest molecules. Confirmed by crystal structural analysis, only the solvents with molecular volume less than 22.3 Å3 could be accommodated in 1 leading to the solvatochromic photoluminescence (PL). The mechanism of solvatochromic PL was also deeply studied, which was found to be closely related to the supramolecular interactions between solvent molecules and the host material. Different functional groups of the solvent molecule can affect its strength of hydrogen bonding with SbCl52–, which is crucial for the distortion level of SbCl52– unit and thus results in not only distinct solvatochromic PL but also distinct thermochromic PL. In addition, they all show typical self-trapped exciton triplet emissions. The additional supramolecular interactions from guest molecules can enhance the photoluminescence quantum yield to be as high as 95%.
Recently zero-dimensional (0-D) inorganic-organic metal halides (IOMHs) have become a promising class of optoelectronic materials. Herein, we report a new photoluminescent (PL) 0-D ...antimony(III)-based IOMH single crystal, namely H
BPZSbCl
·H
O (BPZ = benzylpiperazine). Photophysical characterizations indicate that H
BPZSbCl
·H
O exhibits singlet/triplet dual-band emission. Density functional theory (DFT) calculations suggest that H
BPZSbCl
·H
O has the large energy difference between singlet and triplet states, which might induce the dual emission in this compound. Temperature-dependent PL spectra analyses suggest the soft lattice and strong electron-phonon coupling in this compound. Thermogravimetric analysis shows that the water molecules in the lattice of the title crystal could be removed by thermal treatment, giving rise to a dehydrated phase of H
BPZSbCl
. Interestingly, such structural transformation is accompanied by a reversible PL emission transition between red light (630 nm, dehydrated phase) and yellow light (595 nm, water-containing phase). When being exposed to an environment with 77% relative humidity, the emission color of the dehydrated phase was able to change from red to yellow within 20 s, and the red emission could be restored after reheating. The red to yellow emission switching could be achieved in acetone with water concentration as low as 0.2 vol%. The reversible PL transition phenomenon makes H
BPZSbCl
·H
O a potential material for luminescent water-sensing.
Zero-dimensional (0D) organic–inorganic metal halides (OIMHs) have attracted tremendous attention due to their fascinating optoelectronic properties. Herein, we report an antimony(III)-based 0D OIMH ...of PPh3H2SbCl5 comprising discrete SbCl52– pyramids and protonated triphenylphosphine (PPh3H) cations with a low charge density. Abundant supramolecular interactions including C–H···Cl and rare P–H···Cl hydrogen bonds and C–H···Π and anion···Π interactions lead to a three-dimensional (3D) supramolecular framework structure of PPh3H2SbCl5. Photophysical characterizations indicate that PPh3H2SbCl5 has singlet/triplet dual-band emission. The intersystem crossing between the single and triplet states is tunable upon changing the temperature. Analyses of the Huang–Rhys factor (S), exciton activation energy (E a), and electron–phonon coupling energy (Γop) verify that the soft lattice and strong electron–phonon coupling result in the broad emission of PPh3H2SbCl5, while the excited-state reorganization of the SbCl52– pyramid leads to a large Stokes shift. DFT calculations help provide a deep understanding on the optical property of PPh3H2SbCl5. The title compound could remain stable for more than 1 year without the obvious decay of emission, which may be related to the rigid 3D supramolecular framework.
Here reports the first example of single-crystal-to-single-crystal transformation between two zero-dimensional metal halide isomers containing lattice solvent molecules, which leads to the regulation ...of the photoluminescence performance and optimization of white LED device.
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•The first example of single-crystal-to-single-crystal (SCSC) transformation between two isomers containing lattice solvent molecules in zero-dimensional metal halides.•Regulating photoluminescence (PL) properties has been realized by SCSC transformation.•The mechanisms of title compounds’ PL emission and the PL regulation brought by SCSC transformation have been clarified.•Benefitting from the PL regulation brought by SCSC transformation, the white LED device has been optimized and its CRI has reached as high as 95.3.
Regulating photoluminescence (PL) properties induced by single-crystal-to-single-crystal (SCSC) transformation has sparked significant interest in the research of zero-dimensional organic–inorganic metal halides (0-D OIMHs). To best of our knowledge, the SCSC transformation of solvent-containing 0-D OIMH isomers hasn’t been reported yet. In this work, we report the first example of SCSC transformation between two isomers containing lattice solvent molecules, namely α- and β-EtPPh32SbCl5·MeCN (α- and β-1·MeCN; EtPPh3 = ethyltriphenylphosphonium; MeCN = acetonitrile). Differential scanning calorimetry (DSC) results show that the SCSC transformation from α- to β-1·MeCN is an exothermic process, implying that β-1·MeCN is a more stable phase than α-1·MeCN. Moreover, α- and β-1·MeCN exhibit bright orange (emission peak: 610 nm) and red (emission peak: 635 nm) emission under 360/365 nm excitation, respectively. DFT calculations suggest that the negligible self-absorption and a strong exciton confinement contribute to their effective PL emission. By analyzing temperature-dependent PL spectra, β-1·MeCN has been found to exhibit stronger electron-phonon coupling under excitation than α-1·MeCN. Thus, the broader emission with full width at half maximum (FWHM: 134 vs. 147 nm) and the higher photoluminescence quantum yield (PLQY: 40.37% vs. 70.50%) have been realized by SCSC transformation from α- to β-1·MeCN by heating at 92 °C. Benefitting from the regulation of PL performances brought by SCSC transformation, the white light-emitting-diode (LED) devices assembled by using β-1·MeCN as red phosphor could be optimized, and the CRI reaches as high as 95.3.
Two bismuth(III) halides hybrids with room-temperature phosphorescence (RTP), namely, BPy2Bi2Cl8(bpym) (1, BPy = N-butylpyridinium) and EPy2Bi2Cl8(bpym) (2, EPy = N-ethylpyridinium), were ...synthesized and characterized. Structural comparison reveals that 1 and 2 possess similar anionic zigzaglike chain of Bi2Cl8(bpym) n 2n–; however, different packing modes of anion/cations and thus different weak interactions. Interestingly, the utilization of pyridinium cations with different length of alkyl chain could tune the RTP behaviors efficiently. The RTP quantum yield (QY) is increased more than 5-fold from 1 to 2 probably due to more rigid structure of 2 arising from the additional H-bond and anion−π interactions, as confirmed by Hirshfeld surfaces analyses and PLATON calculations. Moreover, additional π–π interactions in 1 could stabilize the triplet excitons, leading to an average lifetime of 1 (11.36 ms at 77 K and 1.407 ms at 298 K) being higher than 2 (0.3618 ms at 77 K and 0.07511 ms at 298 K). Density functional theory (DFT) calculations confirm that inorganic moiety to organic ligand charge-transfer (IOCT) is involved in the phosphorescence process. The present work provides a new sight into the design of RTP metal halides through studying the structure–RTP relationship.
The selective capture of radioactive cesium, strontium, and lanthanides from liquid nuclear waste is of great significance to environmental remediation and human health. Herein, the rapid and ...selective removal of Cs+, Sr2+, and Eu3+ ions is achieved by two metal sulfides (FJSM-SnS-2 and FJSM-SnS-3). Both structures feature Sn3S7 n 2n– layers with the mixed cations of CH3NH3+ and Bmmim+ (1-butyl-2,3-dimethylimidazolium) as templates. However, the ratios and arrangements of mixed cations in the interlayered spaces are distinct. It is unprecedented that CH3NH3+ and Bmmim+ in FJSM-SnS-2 are alternatingly arranged in different interlayered spaces, whereas they in FJSM-SnS-3 are located in the same interlayered spaces. It is the first time that the ionic liquid cation and protonated organic amine have been simultaneously incorporated into metal sulfides. Both compounds show high capacities, rapid kinetics, and a wide pH active range for Cs+, Sr2+, and Eu3+. Even under excess Na+ ions, both show excellent selectivity in capturing trace Sr2+ and Eu3+ ions. FJSM-SnS-3 presents the highest K d Eu to date. They still retain high removal efficiency even after intense β and γ radiation. Moreover, it is first confirmed by the in situ tracking method of mass spectrometry that the large-sized Bmmim+ ions are exchangeable. It is found that the arrangement of cations between interlayered spaces is a crucial factor affecting ion exchange performance. This work will likely change the consensus that large-sized organic cations are difficult to be exchanged and thus further highlight the great potential of metal sulfide ion exchangers for radionuclide remediation.
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•Two sulfides exhibit high adsorption capacities and ultrafast removal of Eu3+.•Selective Eu3+ adsorption against interfering ions in natural water.•Lanthanides recovery from acidic ...industrial wastewaters is realized.•The adsorption mechanism is ion exchange between Eu3+ and cations.•The soft Lewis basic and flexible layer is beneficial to selective Eu3+ uptake.
Efficient and selective capture of lanthanides from radioactive wastewater containing excessive diverse concentrated salts is challenging but urgently demanded for environmental protection and human health. Herein, we present an effective approach for Eu3+ uptake from complex aqueous solutions by using two layered sulfide adsorbents (Me2NH2)2(Ga2Sb2S7)·H2O (FJSM-GAS-1) and (Et2NH2)2(Ga2Sb2S7)·H2O (FJSM-GAS-2). Both adsorbents exhibit ultrafast kinetics (within 2 min) and high absorption capacities for Eu3+ (127.7 and 115.8 mg/g for FJSM-GAS-1 and FJSM-GAS-2, respectively). The distribution coefficient (Kd) can be as high as 6.39 × 105 and 6.00 × 105 mL/g for FJSM-GAS-1 and FJSM-GAS-2, respectively, exceeding that of reported Eu3+ adsorbents. They still display high selectivity for Eu3+ in presence of excessive competitive cations (e.g., Na+ and K+). Particularly, high Kd values remain for Eu3+ removal from Eu3+-contaminated tap, lake and sea water, and lanthanides recovery from acidic industrial wastewater. Absorbed Eu3+ ions can be facilely eluted using a low-cost method. The adsorption mechanism, illuminated via DFT calculations coupled with characterizations of EA, Raman, XPS and EXAFS, is ion exchange between Eu3+ and interlayered cations owing to the strong interactions between Eu3+ and framework S2−. This work confirms that layered sulfides are promising adsorbents for efficient removal of lanthanides/actinides from wastewater for environmental remediation.
In this review, the structures of halometallate anions based on s2 typed metal ions (Ge2+, Sn2+, Pb2+, Sb3+, Bi3+, Te4+) that are induced by organic cations are summarized. The syntheses, structures, ...and photoluminescence properties for s2 typed halometallates based on aprotic ionic liquids are presented. In addition, the future challenges and prospects are discussed.
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•Organic cation induced s2 typed (e.g., Sb3+,Bi3+) halometallate anions are described.•Luminescent s2 typed halometallates based on aprotic ionic liquids are summarized.•The prospects and the current challenges for s2 typed halometallates are discussed.
Photoluminescence (PL) plays an important role in our daily life as it could be applied to bioimaging, sensing, illumination, display, etc. Inorganic-organic hybrid materials that contain both organic and inorganic parts have widely emerged owing to the achievable dual functions from both organic and inorganic parts. Ionic liquids (ILs) have been widely used as a “green” solvent in the synthesis of functional materials. Especially, relatively chemically stable aprotic ILs have been widely emphasized owing to no proton-transfer and no (or low) volatility. s2 typed metal ions (e.g., Ge2+, Pb2+, Sn2+, Sb3+, Bi3+, Te4+) are potential emissive ions. They are easily coordinated with halogen ions to form s2 typed halometallates. Diverse assemblies of the aprotic ionic liquid cations (AILCs) with the s2 typed halometallate anions could result in a new class of inorganic–organic hybrid ionic metal halides (IOMHs) with excellent and tunable PL properties. This review summarizes the recent progress on the syntheses, structures, and PL properties of IOMHs with the formulas of AILCaMbXcLd (M = s2 typed metal ion, X = halogen, L = N or O-donor organic ligand). Firstly, two types of halometallate anions based on s2 typed metal ions are structurally classified, namely the pure inorganic halometallate anions and the one with coordinating N or O-donor organic ligands; the latter mainly are haloantimonates and halobismuthates. Furthermore, the structural characteristics of IOMHs consisting of s2 typed halometallates and AILCs are provided, followed by the detailed interpretations of their syntheses, structures and PL properties, the PL-structure relationships and luminescent mechanisms. Finally, an outlook about the main challenges and opportunities in this topic are proposed.
It is imperative yet challenging to efficiently sequester the 137Cs+ ion from aqueous solutions because of its highly environmental mobility and extremely high radiotoxicity. The systematical ...clarification for underlying mechanism of Cs+ removal and elution at the molecular level is rare. Here, efficient Cs+ capture is achieved by a thioantimonate MeNH33Sb9S15 (FJSM–SbS) with high capacity, fast kinetics, wide pH durability, excellent β and γ radiation resistances, and facile elution. The Cs+ removal is not significantly impacted by coexisting Na+, K+, Ca2+, Mg2+, and Sr2+ ions which is beneficial to the remediation of Cs+-contaminated real waters. Importantly, the mechanism is directly illuminated by revealing an unprecedented single-crystal to single-crystal structural transformation upon Cs+ uptake and elution processes. The superior Cs+ removal results from an unusual synergy from strong affinity of soft S2– with Cs+, easily exchangeable MeNH3+ cations, and the flexible and robust framework of FJSM–SbS with open windows as trappers.
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