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Photocatalytic reduction of CO 2 is a promising approach to achieve solar-to-chemical energy conversion. However, traditional catalysts usually suffer from low efficiency, poor stability, and selectivity. Here we demonstrate that a large porous and stable metal-organic framework featuring dinuclear Eu(III) 2 clusters as connecting nodes and Ru(phen) 3 -derived ligands as linkers is constructed to catalyze visible-light-driven CO 2 reduction. Photo-excitation of the metalloligands initiates electron injection into the nodes to generate dinuclear {Eu(II)} 2 active sites, which can selectively reduce CO 2 to formate in a two-electron process with a remarkable rate of 321.9 μmol h −1  mmol MOF −1 . The electron transfer from Ru metalloligands to Eu(III) 2 catalytic centers are studied via transient absorption and theoretical calculations, shedding light on the photocatalytic mechanism. This work highlights opportunities in photo-generation of highly active lanthanide clusters stabilized in MOFs, which not only enables efficient photocatalysis but also facilitates mechanistic investigation of photo-driven charge separation processes. Solar-to-chemical CO 2 reduction provides a means to use light’s energy for CO 2 removal and upgrading to useful products, although this photochemical conversion is challenging. Here, authors construct a Europium-containing metal-organic framework that selectively converts CO 2 to formate with light.

The exploration of artificial metal-peptide assemblies (MPAs) is one of the most exciting fields because of their great potential for simulating the dynamics and functionality of natural proteins. However, unfavorable enthalpy changes make forming discrete complexes with large and adaptable cavities from flexible peptide ligands challenging. Here, we present a strategy integrating metal-cluster building blocks and peptides to create chiral metal-peptide assemblies and get a family of enantiopure [ R-/S- Ni 3 L 2 ] n (n = 2, 3, 6) MPAs, including the R-/S- Ni 6 L 4 capsule, the S- Ni 9 L 6 trigonal prism, and the R-/S- Ni 18 L 12 octahedron cage. X-ray crystallography shows MPA formation reactions are highly solvent-condition-dependent, resulting in significant changes in ligand conformation and discrete cavity sizes. Moreover, we demonstrate that a structure transformation from Ni 18 L 12 to Ni 9 L 6 in the presence of benzopyrone molecules depends on the peptide conformational selection in crystallization. This work reveals that a metal-cluster building block approach enables facile bottom-up construction of artificial metal-peptide assemblies. The use of metal clusters to construct artificial protein-mimic structures with adaptable cavities has potential for simulating the dynamics and functionality of natural proteins. Here, the authors develop a family of chiral metal-peptide assemblies using {Ni3} clusters and flexible peptides, resulting in structures such as octahedral cages, trigonal prisms, and capsules.

The construction of inorganic porous frameworks from discrete polyoxometalate (POM) units is a major research challenge. Herein, a three-dimensional (3D) all-inorganic porous structure {Mo 154 } n that consists of classic Mo 154 rings connected by Mo-O-Mo covalent bonds was synthesized. Interestingly, the proton conductivity of the 3D-{Mo 154 } n framework is 1.1×10 −2 S cm −1 at 22 °C and 100% relative humidity (RH), which is one of the highest proton conductivities reported thus far for POM-based conductive materials. Compared to the discrete {Mo 154 } cluster and 1D-{Mo 154 } n , the enhanced conductivity of 3D-{Mo 154 } n suggests that assembling POM-based all-inorganic porous frameworks is a promising method for designing proton-conductive materials.

Ferroelectric materials are characterized by spontaneous electric polarization that can be reversed by inverting an external electric field. Owing to their unique properties, ferroelectric materials have found broad applications in microelectronics, computers, and transducers. Water molecules are dipolar and thus ferroelectric alignment of water molecules is conceivable when water freezes into special forms of ice. Although the ferroelectric ice XI has been proposed to exist on Uranus, Neptune, or Pluto, evidence of a fully proton-ordered ferroelectric ice is still elusive. To date, existence of ferroelectric ice with partial ferroelectric alignment has been demonstrated only in thin films of ice grown on platinum surfaces or within microdomains of alkali-hydroxide doped ice I. Here we report a unique structure of quasi-one-dimensional (H₂O)₁₂n wire confined to a 3D supramolecular architecture of Formula H₄CDTA, trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid; 4,4'-bpy, 4,4'-bipyridine). In stark contrast to the bulk, this 1D water wire not only exhibits enormous dielectric anomalies at approximately 175 and 277 K, respectively, but also undergoes a spontaneous transition between \"1D liquid\" and \"1D ferroelectric ice\" at approximately 277 K. Hitherto unrevealed properties of the 1D water wire will be valuable to the understanding of anomalous properties of water and synthesis of novel ferroelectric materials.

In view of the large difference in the heat and humidity ratio of each air-conditioning zone in the subway, the unified cooling and dehumidification method is adopted, which changes the traditional connection mode of air-conditioning terminal in parallel. A cooling system of air-conditioning terminal surface cooler in series, i.e. large temperature difference series cooling system, is applied to the subway station. The large temperature difference series cooling system is divided into three subsystems: cooling water system, chilled water system and end refrigeration system. The second law of thermodynamics, namely the law of exergy equilibrium and thermoeconomics, is used to analyze the feasibility and economy of the large temperature difference series system and its subsystems. After comparing energy consumption and economy with the conventional air conditioning system, it was found that the exergy efficiency of the chilled water system using the large temperature difference series cooling system was reduced. However, the exergy efficiency of the end refrigeration system in the subway equipment area has been significantly improved, saving electricity costs, and the investment can be recovered in 3.7 years, and the exergy cost has dropped significantly. The use of a large temperature difference series cooling system in a subway station can achieve the effect of energy saving and cost reduction.

Molecular solid solutions of metal clusters containing different metal centers with well-defined structures can accurately regulate the HOMO-LUMO gap, but are rarely available. Herein, a series of colorless lanthanide-titanium-oxo clusters Ln 2 Ti 4 ( μ 2 -O) 2 ( μ 3 -O) 4 (Piv) 10 (THF) 2 (Ln 2 Ti 4 , Ln = Eu, Gd, Tb, and Ce, HPiv = pivalic acid) were synthesized by the reaction of pivalic acid with Ln(Ac) 3 and titanium isopropoxide. The light yellow crystal of cluster solid solutions Eu 2 Ti 4− x Cd x , containing a mixture of Eu 2 Ti 4 and Eu 2 Ti 3 Cd, was obtained by in situ doping Cd 2+ and S 2− . Eu 2 Ti 3.92 Cd 0.08 displays efficient photocatalytic hydrogen evolution activity without a co-catalyst, which is up to 2.6 times that of Eu 2 Ti 4 . Femtosecond time-resolved transient absorption spectroscopy and spin-polarized density functional calculations showed that the enhanced photocatalytic performance of Eu 2 Ti 4− x Cd x can be attributed to the narrower HOMO-LUMO gap and lower LUMO position than that of Eu 2 Ti 4 . This studyprovides an in situ doping method to realize the simple preparation of cluster solid solution.

The reduction of carboxamides into high value-added amines is a very interesting but great challenging topic. Herein we demonstrate that polynuclear lanthanide-oxo clusters Ln 16 (Ln = Eu and Gd) can be used as efficient catalyst to reduce primary and secondary carboxamides to amines with excellent yield of 71%–98% and broad substrates scope. The methodology can extend to the gram-scale synthesis of phenethylamine drug with 93% yield. Based on the isolation and characterization of catalytic intermediates, a catalytic mechanism involving multipath reaction is proposed. This work provides efficient lanthanide cluster catalysts for the reduction of carboxamides to amines.

Photocatalytic reduction of CO 2 is a promising approach to achieve solar-to-chemical energy conversion. However, traditional catalysts usually suffer from low efficiency, poor stability, and selectivity. Here we demonstrate that a large porous and stable metal-organic framework featuring dinuclear Eu(III) 2 clusters as connecting nodes and Ru(phen) 3 -derived ligands as linkers is constructed to catalyze visible-light-driven CO 2 reduction. Photo-excitation of the metalloligands initiates electron injection into the nodes to generate dinuclear Eu(II) 2 active sites, which can selectively reduce CO 2 to formate in a two-electron process with a remarkable rate of 321.9 μmol h −1  mmol MOF −1 . The electron transfer from Ru metalloligands to Eu(III) 2 catalytic centers are studied via transient absorption and theoretical calculations, shedding light on the photocatalytic mechanism. This work highlights opportunities in photo-generation of highly active lanthanide clusters stabilized in MOFs, which not only enables efficient photocatalysis but also facilitates mechanistic investigation of photo-driven charge separation processes.

Metal hydroxides (MAH) consisting of magnesium hydroxide and aluminum hydroxide with a mass ratio of 1:2 were surface-modified by γ-diethoxyphosphorous ester propyldiethoxymethylsilane, boric acid and diphenylsilanediol in xylene under dibutyl tin dilaurate catalyst at 140 °C. Phosphorus, silicon and boron elements covalently bonded to metal hydroxide particles were detected by X-ray photoelectron spectroscopy. The degradation behavior of the surface-modified MAH was characterized by thermogravimetric analysis. The results show that linear low density polyethylene (LLDPE) composite, filled with 50% (mass fraction) of MAH modified by 5.0% (mass fraction) of modifiers, passes the V-0 rating of UL-94 test and shows the limited oxygen index of 34%, and its heat release rate and average effective heat combustion in a cone calorimeter measurement decrease obviously; The mechanical properties of MAH can be improved by surface-modification. The uniform dispersion of particles and strong interfacial bonding between particles and matrix are obtained.