Europium-bearing organic framework with excellent X-ray scintillating luminescence

Two europium-bearing organic frameworks,termed as EuTPO-1 and EuTPO-2(H_(3)TPO=tris(4-carboxylphenyI)-phosphineoxide),are reported in this work.A series of characterizations of EuTPO-1and EuTPO-2,such as X-ray crystallography and photoluminescence spectroscopy,was performed to expatiate their structure and physicochemical properties.Both of them are constructed by dimers of the europium-oxygen subunit of [Eu_(2)O_(16)] and TPO molecule.Benefiting from high X-ray stopping attenuation and excellent luminescence efficiency,they emit sufficient luminescence when irradiated with Xrays.Meanwhile,they possess stable light outputs when exposed to high humidities and strong radiation dose,outperforming the commercial scintillator CsI:Tl.This result paves the way for developing new scintillator and enriches the compound of europium-bearing organic framework with X-ray scintillating luminescence.

Efficient and selective H_(2)O_(2)production through uranyl-assisted photocatalytic oxygen reduction reaction process in a uranium-organic framework

Harnessing solar energy by photocatalytically converting oxygen and water into high-value-added H_(2)O_(2)is a promising way of alleviating both environmental and energy issues.It is worth noting that suppressing detrimental side reactions,such as the generation of·O_(2)^(-),is a critical approach to enhancing H_(2)O_(2)production.Herein,a 2-fold interpenetrating 3D uranium-organic framework(YTU-W-1)was developed and introduced for photocatalytic H_(2)O_(2)production.The material demonstrates a different photocatalytic mechanism when employing uranyl as an initiator,as compared with the conventional semiconductor photocatalytic pathway involving photo-generated charge carriers.Benefiting from the strong hydrogen abstraction effect of the U≡O·and the direct one-step oxygen reduction pathway,YTU-W-1 exhibits enhanced photocatalytic performance for H_(2)O_(2)production with yield efficiency of 221μmol h^(-1)g^(-1).Furthermore,YTU-W-1 displays a high H_(2)O_(2)selectivity of 68%,confirmed by rotating ring-disk electrode(RRDE)measurement.DFTcalculations were used to elucidate the critical role of uranyl in the photocatalytic oxygen reduction reaction for H_(2)O_(2)production.This research introduces an innovative approach to photo-driven H_(2)O_(2)production,underscoring the potential for heterogeneous catalysts to engage in photocatalytic reactions independently of photogenerated charge carriers.

Glycerol Electrooxidation over Precision-Synthesized Gold Nanocrystals with Different Surface Facets

Electrochemical glycerol oxidation(EGO)emerges as a promising route to valorize glycerol,an underutilized byproduct from biodiesel production,into value-added chemicals.This study employed three types of gold(Au)nanocrystals with controlled shapes to elucidate the facet-dependent electrocatalytic behavior in EGO.Octahedral,rhombic dodecahedral,and cubic Au nanocrystals with{111},{110},and{100}facets,respectively,were precisely synthesized with uniform size and shape.Rhombic dodecahedra exhibited the lowest onset potential for EGO due to facile AuOH formation,while octahedra showed enhanced electrochemical activity for glycerol oxidation and resistance to poisoning.In-situ FTIR analysis revealed that Au{111}surfaces selectively favored C_(2) products,whereas Au{100}surfaces promoted C_(3) product formation,highlighting the significant effect of facet orientation on EGO performance and informing catalyst design.

UranyI Phosphonates with Multiple UranyI Coordination Geometries and Low Temperature Phase Transition

Main observation and conclusion Two new uranium(VI)phosphonate compounds,namely K_(8)[N(C_(2)H_(5))_(4)]_(2)(UO_(2))_(17)(H_(2)O)_(4)[CH_(2)(PO_(3))_(2)]_(8)[CH_(2)(PO_(3))(PO_(3)H)]_(4)·16(H_(2)O)(1)and[N(C_(2)H_(5))_(4)]_(4)(H_(3)O)_(2)(UO_(2))_(10)[CH_(2)(PO_(3))_(2)]_(5)[CH_(2)(PO_(3))(PO_(3)H)]_(2)·10H_(2)O(2),have been synthesized under mild hydro/solvothermal condition.The structural analysis of the two compounds reveals that they both contain all three typical coordination geometries of the U(VI)ions,including UO;tetragonal,UO,pentagonal,and UOg hexagonal bipyramids.Moreover,compound 1 displays a tempera-ture-induced single crystal to single crystal phase transformation as confirmed by the Single-crystal X-ray diffraction data collected at different temperatures.Temperature-dependent fluorescence spectra presented herein illustrate the perturbation of the electronic structure of uranyl centers.

A Tetravalent Plutonium Organic Framework Containing[Pu_(2)O_(16)]Dimers as Secondary Building Units:Synthesis,Structure,and Radiation Stability

The second example of tetravalent plutonium carboxyl-based organic framework,^(242)Pu(OH)[PO[(C_(6)H_(4))COO]_(3)]·H_(2)O,termed as PuTPO(TPO=tris(4-carboxylphenyl)-phosphineoxide),was reported in this work.A series of characterizations of PuTPO,such as X-ray crystallography and solid-state UV-Vis-NIR spectroscopy,were carried out to expatiate its structure and physicochemical properties.PuTPO is constructed by dimers of the plutonium-oxygen subunit of[Pu_(2)O_(16)].Characteristic peaks located at approximately 1100 nm can be considered to be the fingerprint peaks of tetravalent plutonium.While PuTPO can maintain high crystallinity within several months after synthesis,it exhibits a radiation-induced swelling effect probed by the expansion of cell parameter of b axis after self-irradiation fromα-decay of ^(242)Pu.This result enriches the inventory of tetravalent plutonium compounds and provides an insight into the irradiation resistance of metal-organic frameworks.

A Trivalent Americium Organic Framework with Decent Structural Stability against Self-Irradiation

We reported the synthesis,single crystal structure,and solid-state UV-Vis-NIR spectroscopy of a new transplutonium metal-organic framework(MOFs),Am(H_(2)O)[PO[(C6H4)COO]_(3)],denoted as AmTPO(TPO=tris(4-carboxylphenyl)-phosphineoxide).AmTPO forms a three-dimensional metal-organic framework structure with americium dimers as the secondary building unit.Clear 5f→5f transi-tions attributed to trivalent americium was observed in the absorption spectrum of AmTPO ranging from 300 to 1200 nm.Notably,AmTPO can maintain the crystallinity with no observable structural degradation within several months after being synthesized,re-vealing a long-term radiation resistance of this structure and the potential application of MOFs as a platform for nuclear waste dis-posal.

Superior Iodine Uptake Capacity Enabled by an Open Metal-Sulfide Framework Composed of Three Types of Active Sites

Efficient adsorption of gaseous radioiodine is pivotal for the sustainable development of nuclear energy and the long-termradiation safety of the ecological system.However,state-of-the-art adsorbents(e.g.metal-organic frameworks and covalent-organic frameworks)currently under exploration suffer severely from limited adsorption capacity,especially under a real-world scenariowith extremely lowradioiodine concentration and elevated temperature.This mostly originates from the relatively weak sorption driving forces mainly determinedby the iodine-adsorbent interaction consistingof noncovalent interactionswith a small fraction of strong chemical bonding.Here,we document the discovery of an open metal-sulfide framework((NH_(4))_(2)(Sn_(3)S_(7)),donated as SCU-SnS)constructed by three different types of active sites as a superior iodine adsorbent.Benefiting from the ability of iodine for pre-enrichment into the framework by charge-balancing NH_(4)^(+)through N-H···I interaction,the efficient reduction of I^(2)affording I^(-)by S^(2-),and extremely high binding affinity between Sn_(4)^(+)and I^(-),SCU-SnS exhibit a record-breaking iodine adsorption capacity(2.12 g/g)under dynamic breakthrough conditions and the highest static capacity(6.12 g/g)among all reported inorganic adsorbents,both at 348 K.Its facile synthesis and low cost endow SCU-SnS with powerful application potential for the nuclear industry.

Simulating soil erodibility in southeastern China using a sequential Gaussian algorithm

Soil erodibility(K)is a key factor of soil erosion,and its appropriate quantification and interpolation are vitally important for soil and water conservation.The traditional point-represent-polygon approaches and common kriging method for the estimation of K,however,do not sufficiently represent the original data.The objectives of this study were to simulate the spatial distribution of K using a sequential Gaussian algorithm and analyze the uncertainty in evaluating the risk of soil erodibility in southeastern China.We determined 101 sampling points in the area and collected disturbed soil samples from the 0-20 cm layer at each point.Soil properties were determined,and K was calculated using five common models:the EPIC(Erosion/Productivity Impact Calculator),approximate nomograph,Torri,Shirazi,and Wang models.Among the chosen models,the EPIC model performed the best at estimating K(KEPIC),which ranged from 0.019 to 0.060 t ha h(ha MJ mm)^(-1),with a mean of 0.043 t ha h(ha MJ mm)^(-1).The KEPIC was moderately spatially variable and had a limited spatial structure,increasing from south to north in our study area,and all spatial simulations using the cooperative kriging(CK)interpolation and the sequential Gaussian simulation(SGS)with 10,25,50,100,200,and 500 realizations had acceptable accuracies.The CK interpolation narrowed the range,and the SGS maintained the original characteristics of the calculated data.The proportions of the risk area were 38.0% and 10.1%,when the risk probability for K was 60% and 80%,respectively,and high risk areas were mostly located in the north.The results provide scientific guidance for managing the risk of soil erodibility in southeastern China.

Chromate separation by selective crystallization

A new paradigm to remove toxic chromate anions from aqueous solution by crystallization of chromatewater clusters with imine-linked guanidinium cationic ligands is introduced.The guanidium-based cationic ligand was easily prepared through the imine condensation of an alde hyde and aminoguanidine hydrochloride.The cationic imine-linked guanidinium liga nd(BBIG-CI)showed a high re moval capacity(292.5 mg/g)in the solutions.Rapid decontamination of chromate anions from the wastewater by this cationic ligand was resulted from an instantaneous crystallization.The produced guanidium chromate salts have an extremely low solubility(Ksp,BBIG=8.19×10^9).Such superior removal performance of these mate rials was attributed to the cha rge-assisted hydrogen bonding between the cationic ligand and chromate-water hydrate anions,which was revealed by the single-crystal X-ray diffraction analysis and density functional theory(DFT)calculations.In addition,the succes s ful recove ry of the guanidium-based ligand makes it more attractive for real-world applications.

A uranyl based coordination polymer showing response to low-dosage ionizing radiations down to 10^(−5) Gy

Radiation detection material is a central component of nuclear technology finding applications in many critical fields.Developing a highly radiation-sensitive material that shows a facilely detectable response to ultra-low dosage of radiation is a long-term research target and remains to be a challenge.Previously reported most optimal chemical radiation dosimeter can detect low-dosage X-andγ-ray radiations down to 10^(−4) Gy.We document here a new photoresponsive coordination polymer showing upgraded radiation detection capabilities with the detection limit on the radiation dose one order of magnitude lower than the previous record.The radiation induced photoluminescence quenching process was elucidated by multiple spectroscopic characterizations.