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Actinide complexes, which could enable the electrocatalytic H

Radiation dosimeters displaying conspicuous response of irradiance are highly desirable, owing to the growing demand of monitoring high-energy radiation and environmental exposure. Herein, we present a case of dosimetry based on a discrete nanocluster, [Th6(OH)4(O)4(H2O)6](TPC)8(HCOO)4∙4DMF∙H2O (Th-SINAP-100), by judiciously incorporating heavy Th6 polynuclear centers as radiation attenuator and organic linkers as photo-responsive sensor. Interestingly, dual-module photochromic transitions upon multiple external stimuli including UV, β-ray, and γ-ray are integrated into this single material. The striking color change, and more significantly, the visible color transition of luminescence in response to accumulating radiation dose allow an on-site quantitative platform for naked-eye detection of ionization radiations over a broad range (1–80 kGy). Single crystal X-ray diffraction and density functional theory calculations reveal that the dual-module photochromism can be attributed to the π(TPC) → π*(TPC) intermolecular charge transfer driven by enhanced π-π stacking interaction between the adjacent TPC moieties upon irradiation., Radiation dosimeters that measure ionizing radiations over a broad range and allow for direct readout are desirable. Here, the authors present a dual-mode photochromic thorium-based metal-organic nanocluster that enables direct visible colorimetric dosimetry of UV, β-ray, and γ-ray radiation.

A series of hetero-bimetallic actinide complexes of the Schiff-base polypyrrolic macrocycle (L), featuring cation-cation interactions (CCIs), were systematically investigated using relativistic density functional theory (DFT). The tetrahydrofuran (THF) solvated complex [(THF)(OUVIOUIV)(THF)(L)]2+ has high reaction free energy (ΔrG), and its replacement with electron-donating iodine promotes the reaction thermodynamics to obtain uranyl iodide [(I)(OUVIOUIV)(I)(L)]2+ (UVI-UIV). Retaining this coordination geometry, calculations have been extended to other An(IV) (An = Th, Pa, Np, Pu), i.e., for the substitution of U(IV) to obtain UVI-AnIV. As a consequence, the reaction free energy is appreciably lowered, suggesting the thermodynamic feasibility for the experimental synthesis of these bimetallic complexes. Among all UVI-AnIV, the electron-spin density and high-lying occupied orbitals of UVI-PaIV show a large extent of electron transfer from electron-rich Pa(IV) to electron-deficient U(VI), leading to a more stable UV-PaV oxidation state. Additionally, the shortest bond distance and the comparatively negative Eint of the Pa-Oendo bond suggest more positive and negative charges (Q) of Pa and endo-oxo atoms, respectively. As a result of the enhanced Pa-Oendo bond and strong CCI in UVI-PaIV along with the corresponding lowest reaction free energy among all of the optimized complexes, uranyl species is a better candidate for the experimental synthesis in the ultimate context of environmental remediation.

To date, the experimental studies on Nd-based metallofullerenes are only limited to spectroscopic characterizations. In this work, the molecular structures of Nd@C82(I,II) isomers, including the isomeric symmetry of the C cage and the position of endohedral Nd atom, as well as their unique two-dimensional (2D)-layered crystallographic packing structures were initially and unambiguously elucidated, based on the X-ray structural analyses of the cocrystals of Nd@C82(I) or Nd@C82(II) with cocrystallizing agent decapyrrylcorannulene (DPC). In the V-shaped unit cell, the endohedral Nd atom prefers a site as far away from the DPC molecules as possible because of the unevenly distributed charge on the C cage mainly related to the charge transfers from the endohedral Nd atom, cocrystallizing agent DPC, and solvent toluene molecules to the C82 cage. Apart from charge transfers, multiple C-H···π intermolecular interactions are also confirmed to play important roles both for the orientation of the C cage correlated with the preferential sites of the endohedral Nd atom and for the 2D-layered packing structures within the cocrystals. Density functional theory computations offered theoretical support for the molecular structures of Nd@C82(I,II) isomers, the valence of the endohedral Nd atom (between II+ and III+), and the global ground state, i.e., the Nd@C2v(9)-C82 isomer in the quintet state.

Due to the powerful reducing ability of the metal active site, low-valent uranium complexes show remarkable performance in activating thermodynamically stable and kinetically inert small molecules. In this work, experimentally known uranium metallocenes [Cp3U]z (z = 0 and +1) were intensively studied using relativistic density functional theory for their activation of small molecules (X = CO2, N2, CO and NO). Regardless of whether z = 0 or +1, a weak double bond was realized between uranium and NO, which is in agreement with a previous study; a weak single bond with the dative nature was assigned to other small-molecule uranium adducts. A general order for the uranium–small molecule bond strength, NO > CO > N2 > CO2, has been built, the trend being exactly the same as the computed reduction potentials. These are corroborated by energetics and experimental results that (i) analogues of the first three [Cp3U(X)] adducts were crystallographically identified but the one of [Cp3U(CO2)] was not, and (ii) much higher X gas pressure was required to synthesize [Cp3U(N2)] than for [Cp3U(CO)]. Additionally, the experimentally inaccessible CO2 adduct was rationalized using thermodynamic and kinetic calculations as well as geometric/electronic properties and bonding analyses.

Due to its good properties and low cost, melamine formaldehyde foam has been widely used in cars, furniture and construction. However, how to recycle the spent foam still remains challenging for scientists. In this work, a new method was designed to prepare N-doped carbon dot (NCD) materials by calcining sodium lignin sulfonate/melamine formaldehyde foam (LSMF) via one step. TEM, IR and XPS were used to characterize the structure and morphology of newly-synthesized NCDs. It is shown that carbon powder is obtainable by calcination. Since it derives from the collapse of the foam structure of LSMF, the carbon powder can almost completely dissolve in deionized water. The particle size ranges from 5 to 20 nm. The fluorescence properties of NCDs were studied by fluorescence spectroscopy. A strong emission has been detected at 580 nm with the quantum yield of 2.94%. When applying NCDs to detect various metal ions, there is a significant fluorescence quenching effect and good selectivity for Fe3+. The mechanism has been hypothesised. Our study provides a method for productive preparation of NCDs from spent foam.

To explore the innovative uranyl(V) complexes by deeply understanding their coordination stability, relativistic density functional theory calculations have been performed to investigate the experimentally reported [(py)(R2AlOUVO)(py)(H2L)] [R = Me (1), iBu (2)] and [{(py)3MOUVO}(py)(H2L)] [M = Li (3), Na (4), K (5)] and their uranyl(VI) counterparts. Structural and topological analyses along with transformation-reaction energies and redox potentials were systematically studied. Geometrical and quantum theory of atoms in molecules analyses implied a linear U-Oexo-M feature in 1-3 and a bent one in 4 and 5. The calculated free energies (ΔrG) of reactions transforming 1/2 into 3/4/5 confirmed a higher stability of the latter ones, which were further corroborated by their reduction potentials (E0). The E0 value of 5 versus uranyl(VI) is close to its experimental value, particularly in solvation with spin-orbit coupling. The highest occupied and lowest unoccupied molecular orbitals of uranyl(V) and uranyl(VI) have predominant U(5fδ) character. Compared to mononuclear uranyl(VI), the coordination of aluminum and alkali metals to uranyl exo-oxo significantly contributes to the stabilization of uranyl(V) by altering the E0 value from -1.59 to -0.85, -0.91, -1.33, -1.50, and -1.46 V, respectively. The calculation results show a more positive E0 than that of the precursor 6VI/6 without exo-oxo coordination. The calculated E0 values of 3-5 are certainly more negative than those of 1 and 2. The alkali metals were found to activate U═O bonds more easily/readily than aluminum by coordination to the exo-oxo atom. In brief, the uranyl exo-oxo cation-cation-interaction enhanced the reduction ability from its uranyl(VI) analogue and raised the stability of the UV center.

Catalysis operated on supported single metal atom is considered as one of the vital efforts for chemical and energy conversion. Despite the enormous amount of research on single transition metal (TM) enhanced graphdiyne (GDY) material, its modification with slightly depleted uranium remains unexplored. Herein, we conducted relativistic density functional theory (DFT) calculations for the accumulation of atomic uranium inside size-suitable GDY pore. The stability of graphdiyne-uranium (GDY-U) is corroborated in terms of short U–C bond distances (2.34–2.44 A), with local depletion of charge and greater U(5f)-C(p) molecular orbital overlap. The magnificent structural and electronic properties of GDY-U system qualify it for the investigation of hydrogen evolution reaction (HER). The HER performance of all exposed sites, including central metal atom and four dissimilarly coordinated acetylenic carbons has been examined and compared with that of pure GDY. As the overall HER interfacial descriptor, free energy change of the intermediate state (ΔGH∗) at the central metal surface of GDY-U was found to be most favorable (0.153 eV) amongst all sites and far superior to those of pure GDY. In addition to the uranium surface, the coordinated carbons also show improved HER activity, indicating the enhancement of the system upon metal insertion. The calculated ΔGH∗ of the GDY-U system here is comparable to some of the recently reported GDY-TM materials, suggesting that atomic uranium could be an exceptional alternative for applied common catalysts.

The lignin amine (LA) was exploited to prepare dually N/S-doped carbon (NSC), which was endowed with intriguing porous structure by Fe3O4 template. N and S elements, originating from LA, are doped into the materials. NSC possesses diverse-scale 3D pores. The macropores are made by Fe3O4, which facilitate to produce meso and micro pores on their walls by KOH activation. The sample prepared at 700 °C (NSC-700) is found to have the largest specific surface area (1199 cm2 g−1) and specific capacity (241 F g−1 at current density of 1 A g−1). Its capacity is 260% as high as that of lignin amine carbon (LAC) prepared without adding Fe3O4. Excellent rate performance is unraveled because of possessing 82% specific capacity at 20 A g−1 and 27.2 Wh kg−1 energy density at 10000 W kg−1 power density. Moreover, the specific capacity maintains 95.0% after 3000 cycles, indicating good electrochemical stability. The good electrical performance of NSC-700 is attributed to its interesting electronic properties that are induced by special pore structure. Because of having merits such as high rate performance, long life, large specific capacity and low cost, our NSC is anticipated to be a promising capacitor as electrode material.

With the reported CO2 activation for the oxidation of benzene to phenol (-ENE → -OL) by the graphitic carbon nitride g-C3N4 (CN) via an artificial photosynthetic route as inspiration, high-valent a...

To advance biomass-metal oxide composite synthesis, develop its interfacial chemistry and raise its performance in applications, specifying local structures and their effects are of great importance. Herein, a facile hydrothermal route was utilized to prepare a composite of renewable cellulose and zinc oxide. Microstructures from nanoscale to atomic level were examined with electron microscopy, spectroscopic technique and relativistic density functional theory. ZnO nanoparticles uniformly grow on linear cellulose nanofiber, affording an orderly hierarchical structure in general. Chemical interfacial coupling is computationally borne out. Three types of local structures with different hydrogen locations are energetically favored; notably the hydrogen-transfer one is most possibly occurring in the composite, whose interfacial interaction is dominated by orbital attractions and interfacial strength reaches − 5.06 eV. Electronic structures of the composite rationalized experimental diffuse reflectance spectra. The influence of different hydrogen positions in composite on various properties was discussed in detail. Experimental and computational characterizations unravel local structures of a typical cellulose–ZnO composite, which show different hydrogen positions. Hydrogen-transfer isomers are found the most possibly occurring, resembling the photoanode in dye-sensitized solar cells. The interfacial nature and interaction strength as well as electronic structures are determined by hydrogen locations.

Versatile graphdiyne (GDY) substrate has been modified by numerous transition metals and resulting composites showed excellent photo/electro-catalytic performance. However, GDY materials modified by actinides that are stockpiled waste product due to large-scale use in nuclear industry, are particularly scarce and remains great challenge. To deeply understand the structural properties, GDY complexating actinyl (AnmO2)n+ (An = U, Np, Pu; m = VI, V) species with its atomistic pore was investigated by relativistic density functional theory (DFT). The GDY pore was found suitable to hold actinyl species, by forming organometallic AnC dative bonds. This chemical coupling interaction was further confirmed by quantum theory of atoms-in-molecule and electronic structure calculations. The GDY-uranyl(V), for instance, shows a π(UC) bonding HOMO, which is anticipated to improve electron transfer between ligand and metal. Orbital structures and compositions of complexes suggest their implication towards catalysis, which were further corroborated by calculations on redox potentials of GDY-actinyl complexes. Hence, our results show the potential applications of GDY complexating actinyl species towards novel catalytic surfaces. Keywords: Graphdiyne-actinyl, Electronic structures and bonding, Redox properties, Relativistic DFT calculations

By fine tuning the metal mole ratio, CoAl-LDHs (CA) with a 2D nanosheet structure were successfully prepared via a one-step hydrothermal method using urea as both precipitator and pore-forming agent. The morphology of CA samples shows uniform and thin porous hexagonal nanosheets. In particular, CA2-1, prepared with the 2 : 1 molar ratio for Co and Al, respectively, has the highest surface area (54 m2 g−1); its average transverse size of platelets is 2.54 μm with a thickness of around 19.30 nm and inter-plate spacing of about 0.2 μm. The sample exhibits a high sensing performance (response value of 17.09) towards 100 ppm NOx, fast response time (4.27 s) and a low limit of detection (down to 0.01 ppm) at room temperature. Furthermore, CA2-1 shows long -term stability (60 days) and a better selectivity towards NOx at room temperature. The excellent performance of the fabricated sensor is attributed to the special hexagonal structure of the 2D thin nanosheets with abundant mesopores, where the active sites provide fast adsorption and transportation channels, promote oxygen chemisorption, and eventually decrease the diffusion energy barrier for NOx molecules. Furthermore, hydrogen bonds between water molecules and OH− could serve as a bridge, thus providing a channel for rapid electron transfer. This easy synthetic approach and good gas sensing performance allow CoAl-LDHs to be great potential materials in the field of NOx gas sensing.

Four novel polyoxouranium-based uranyl carboxylates have been constructed by using a combination of three silicon-centered carboxylate ligands and polyoxouranium building blocks. Interesting oligomerization of the uranyl groups from three types of tetrameric units in 1 and 2 to octameric [(UO2)8(μ3-OH)6(μ2-OH)2(H2O)4]8+ in 3 and ultimately infinite polyoxouranium chains in 4 was observed. The 3D structure of 2 contains two different linear tetramers, whose structures are totally different from seven types of tetranuclear motifs previously observed in uranyl carboxylates. Compound 3 displays a rare octanuclear polyoxouranium brick; it is fabricated by the association of eight uranyl units in pentagonal-bipyramidal geometry that involves the edge-sharing polyhedral connection mode, which are further linked by four isolated UO7 pentagonal bipyramids to create a complicated 3D framework. These newly synthesized hybrid materials were extensively characterized by single crystal analysis, thermogravimetric analysis (TG) and different spectroscopic techniques (IR, UV-vis, and luminescence spectroscopy), which show well-resolved characteristic "five-finger" emission of the uranyl ions under excitation at 420 nm. Relativistic density functional theory (DFT) was used to explore five model compounds that theoretically simulate experimental real compounds. Experimental spectroscopy was rationalized by electronic-structure analysis.

Developing materials that possess colorimetric responses to external stimuli is a promising strategy for addressing the current challenges in radiation dosimetry. Currently, colorimetric ionizing-radiation-responsive materials remain underexplored, and those with multistimuli response are rare. Herein, the integration of thorium cation and photoresponsive terpyridine carboxylate ligand gives rise to a thorium nanocluster

Designing novel catalysts is essential for the efficient conversion of metal alkylidyne into metal oxo ketene complexes in the presence of CO

The specification of the local structure and clarification of interfacial interactions of biomass composites is of tremendous significance in synthesizing novel materials and advancing their performance in various demanding applications. However, it remains challenging due to the limitations of experimental techniques, particularly for the manner that biomass composites commonly have hydrogen bonds involved in the vicinity of active sites and interfaces. Herein, the cellulose/Mg(OH)2 nanocomposite has been synthesized via a simple hydrothermal approach and examined by density functional theory (DFT) calculations. The composite exhibits a layered morphology; Mg(OH)2 flakes are around 50 nm in size and well-dispersed. They either anchor onto the cellulose surface or intercalate between layers. The specific composite structure was confirmed theoretically, in line with XRD, SEM and TEM observations. The interfacial interactions were found to be hydrogen bonding. The average adsorption energy per hydroxyl group was computed to be within −0.47 and −0.26 eV for a composite model comprising three cellulose chains and a two-layered Mg(OH)2 cluster. The combined computational/experimental results allow to postulate the antibacterial mechanism of the nanocomposite.

The ZnO/Ag/cellulose composite (ZAC) with excellent photocatalytic activity of degrading benzene and phenol in VOCs has been successfully synthesized. EDS, TEM, XPS and UV-vis analyses show that the ZAC is a ternary composite. It is composed of Ag, ZnO and cellulose, where the cellulose works as the substrate to anchor the other two components. The X-ray diffraction patterns find well-crystallized ZnO nanoparticles. Multiple PL peaks in the visible region measured for ZAC, imply rich defects on ZnO. It is observed that Ag nanoparticles are mainly attached on ZnO in the composite, which would raise the separation efficiency of photogenerated electrons and holes. Photocatalytic degradation shows that ZAC is able to decompose almost 100% phenol and 19% benzene in VOCs under UV light irradiation (6 W) which is almost no harm to human body. Due to the renewable cellulose, our ternary composite ZAC imparts low-cost, easily recycled and flexible merits, which might be applied in the indoor VOCs treatment.

The recognition and in-depth understanding of inverse trans influence (ITI) have successfully guided the synthesis of novel actinide complexes and enriched actinide chemistry. Those complexes, however, are mainly limited to the involvement of high-valence actinide and/or metal-ligand multiple bonds. Examples containing both low oxidation state actinide and metal-metal single bond remain rare. Herein, more than 20 actinide-transition metal (An-TM) complexes of phosphinoaryl oxide ligands have been designed in accordance with several experimentally known analogs, by changing the metal atoms (An = Th, Pa, U, Np, and Pu; and TM = Ni, Pd, and Pt), actinide oxidation states (IV and III) and metal-metal axial donor ligands (X = Me3SiO, F, Cl, Br, and I). The relativistic density functional theory study of structural (trans-An-X and cis-An-O toward An-TM), bonding (topological electron/energy density), and electronic properties reveals the order of the ITI stabilizing actinide-metal bond. Computed electron affinity (EA) values, related to the electrochemical reduction, linearly correlate with experimentally measured reduction potentials. Although the same ITI order for the ligand donors was shown as in a previous study, the correlation between electrochemical reduction and the ITI was found to be weak when the actinide atoms were changed. For most complexes, the reduction is primarily of an actinide-based mechanism with minor participation of transition metal and phosphinoaryl oxide, whereas that of thorium-nickel complexes is different.

Heterobimetallic uranium-transition metal (U-TM) complexes have abundant active centers (two metals and several ancillary ligands with various donor atoms) and possible metal-metal bonding interaction, leading to diversified electronic structures and rather complicated electronic transition types. In this regard, a comprehensive and systematic theoretical study is highly desired although challenging. In the work, density functional theory (DFT) was utilized to examine a series of uranium-group 10 metal complexes supported by bidentate phosphinoaryl oxide ligands (labeled as L). TM (Ni, Pd, and Pt), uranium oxidation state (IV and III) and axial donor (I, Br, Cl, F, Me3SiO, and vacant) were varied. Calculations demonstrate an intrinsic TM → U dative bond. The order of bond strength of U-Ni > U-Pt > U-Pd is suggested by the formal shortness ratios, quantum theory of atoms in molecule (QTAIM) data, interaction energy ( Eint), and bond orders calculated at various levels of theory. It is further evidenced by relativistic effects of heavy metal, natural orbital population and electronic spectroscopy. Regarding U-Ni complexes with different axial donors, metal-metal distances are found to be linearly correlated with QTAIM data/ Eint/bond orders. Experimental UV-vis-NIR spectra were well reproduced by time-dependent DFT calculations. Complicated visible-light absorption bands, whose understanding remains unclear for many experimentally known heterobimetallic complexes, were rationalized in the work, along with NIR bands assigned as 5f → 5f transitions.

Commonly accepted uranium oxidation states in molecular complexes are III+ to VI+. Recently, this has been extended experimentally by the synthesis of seminal U(II) complexes, Y·[U(Cp′)3] and Y·[URE] (Y = K+(2.2.2-cryptand), Cp′ = C5H4SiMe3, H3RE = (Ad,MeArOH)3mesitylene and Ad = adamantyl). Relativistic density functional theory has been applied to explore whether the uranium oxidation state (+I) is possibly accessible. Calculations show that the U(I) complex of a heterocalix[4]arene (H2L) is energetically stable. It features a 5f5-dominated electronic configuration, four δ(U–Ar)-bond orbitals and a moderate UII/UI reduction potential. Its stability and structural/bonding/energetic properties were corroborated by comparisons with theoretically designed complexes [UI(Cp′)3]2− and [UIRE]2−.

The reaction of (THF)(H2L)(UVIO2) (L is a tetra-anion of polypyrrolic macrocycle) with AnIIICp3 (Cp = cyclopentadienyl) afforded two intriguing cation–cation interaction (CCI) complexes (i.e., uranyl-Np and -U), but did not yield the uranyl−Pu analogue. To complement and extend experimental results, a scalar relativistic density functional theory has been performed on the formation reactions and various relevant properties of (THF)(A2L)(OUO)–An(CpX)3 (A = Li and H; An = Pu, Np, and U; X = Me, H, Cl, and SiMe3). Inspired by a strategy that improves uranyl precursor reactivity, we utilized (THF)(Li2L)(UVIO2) instead to gain a uranyl–Pu complex. Reaction free energy is reduced even to be negative (i.e., undergoing an exergonic process), which provides the thermodynamic possibility for experimental synthesis. This manner is further rationalized by the lithiated precursor showing the increased Li–Oendo bond, uranium oxidation ability (VI → V), and exo–oxo basicity, as well as the lithiated uranyl–Pu product ha...

The interfacial chemistry of nanocomposite materials is of overarching importance in the separation and purification science; moreover, its understanding helps to guide synthesis, clarify structure-property relationship and unearth novel applications. However, the composites feature rather complicated local structures and hydrogen bonds are often involved in the interface and the vicinity of active sites. In this regard, density functional theory first-principle calculations associated with experimental study have synergistically examined two-dimensional (2D) magnesium hydroxide material with different layers and their adsorption toward cellobiose. Hydrogen bonds are found responsible for the interfacial coupling, which make it vital to cover the dispersion correction in the calculation. The average adsorption energy ranges from -0.29 to -0.35 eV, falling well within the range of reported hydrogen-bonding strength. On the basis of calculated structural/interfacial properties and experimental findings, the 2D Mg(OH)

To explore the innovative uranyl(V) complexes by deeply understanding their coordination stability, relativistic density functional theory calculations have been performed to investigate the experimentally reported [(py)(R

Radiation dosimeters displaying conspicuous response of irradiance are highly desirable over the recent decade owing to the growing demand of monitoring high-energy radiation and environmental exposure. Herein, we present the first case of dosimetry based on a discrete nanocluster by judicious incorporating heavy Th6 polynuclear centers as radiation attenuator and organic linkers as photo-responsive sensor to enhance chromic response. Rather unusual dual-module photochromic transitions upon multiple external stimuli including UV, β-ray, and γ-ray are integrated into this single material. The striking color change, and more significantly, the visible chromic transition of luminescence in response to accumulating radiation dose allow an on-site quantitative platform for naked-eye detection of ionization radiations over a broad range (1–80 kGy). SC-XRD and DFT calculations revealed that the dual-module photochromism can be attributed to a unique π(TPC)→π*(TPC) intermolecular charge transfer (IeMCT) driven by enhanced π-π stacking interaction between the adjacent TPC moieties upon irradiations.

The redox properties of actinides play a significant role in manipulating organometallic chemistry and energy/environment science, for being involved in fundamental concepts (oxidation state, bonding and reactivity), nuclear fuel cycles and contamination remediation. Herein, a series of trans-calix[2]pyrrole[2]benzene (H2L2) actinide complexes (An = Ac–Pu, and oxidation states of +II and +III) have been studied by relativistic density functional theory. Reduction potentials (E0) of [AnL2]+/[AnL2] were computed within −2.45 and −1.64 V versus Fc+/Fc in THF, comparable to experimental values of −2.50 V for [UL1e]/[UL1e]− (H3L1e = (Ad,MeArOH)3mesitylene and Ad = adamantyl) and −2.35 V for [U(CpiPr)2]+/[U(CpiPr)2] (CpiPr = C5iPr5). The E0 values show an overall increasing trend from Ac to Pu but a break point at Np being lower than adjacent elements. The arene/actinide mixed reduction mechanism is proposed, showing arenes predominant in Ac–Pa complexes but diverting to metal-centered domination in U–Pu ones. Besides being consistent with previously reported those of AnIII/AnII couples, the changing trend of our reduction potentials is corroborated by geometric data, topological analysis of bonds and electronic structures as well as additional calculations on actinide complexes ligated by tris(alkyloxide)arene, silyl-cyclopentadiene and octadentate Schiff-base polypyrrole in terms of electron affinity. The regularity would help to explore synthesis and property of novel actinide(II) complex.

With the reported CO

The composite of hollow In2O3 tubes derived from metal-organic framework (MOF) and two-dimensional (2D) thin sheets g-C3N4 sensing material was successfully prepared via hydrothermal method. The structure, surface morphology and elementary of In2O3/g-C3N4 were characterized by XRD, FT-IR, TEM, SEM and XPS. The response of In2O3/g-C3N4 to 100 ppm NOx is 294.9 at room temperature, which is 15 times higher than that of pure In2O3 tubes. In2O3/g-C3N4 sensor exhibits a low detection limit of 2.9 ppb. The enhanced sensing performance could be ascribed to the heterojunction and the synergistic effect between In2O3 tubes and thin sheets g-C3N4. Obviously, In2O3/g-C3N4 is a novel and promising material for the selective detection of NOx at room temperature.

To remedy the heavy metal ion (HMI) pollution, unravel the relationship of material microstructure and removal performance and clarify relevant mechanism, magnesium-aluminum layered double oxide (MgAl-LDO) has been fabricated via a template method using cellulose. The variously performed characterizations show that ultra-thin flakes of about 5 nm are successfully accessible with the size of 50 ~ 100 nm. They are smaller than the ones prepared without the addition of cellulose. The distinctive structural feature endows the newly-synthesized LDO with large removal capacity for HMIs. Towards Cd2+, Pb2+ and Cu2+, the removal capacity reaches as high as 1422.3, 1336.8 and 1135.4 mg·g−1, respectively. Moreover, the highly achieved durability makes our LDO applicable to treating the polluted water. The mechanism of cation exchange along with deposition has been postulated. The Mg-OH moiety in the sample is found to dominate the HMI removal. The experimental findings are borne out by the first-principle density functional theory calculations on geometries, thermodynamics and electronic structures.

Lignin is one of the most abundant materials in nature, but its highly value-adding utilization is still a challenge. Herein, sodium lignosulfonate (SLS) was adopted to fabricate ZnO centering on the concept of “using lignin valuably”. And the g-C3N4/S-ZnO (CNSZ) composite was successfully prepared. SLS serves as a linkage reagent, interacting with ZnO on one hand and simultaneously helping urea (processor of g-C3N4) to be deposited with ZnO. The structure and morphology of CNSZ were fully characterized. It is shown that g-C3N4 co-exists in the composite. Meanwhile, EDS and XPS analyses indicate the presence of S in the composite, which originates from SLS. The composite is found to show good photocatalytic property. Its degradation efficiency on phenol is 8.5 times higher than bare ZnO. Due to its facile synthesis and excellent property, the newly-synthesized CNSZ is anticipated to be promising for water treatment application.

In this study, a chain structure consisting of single crystal Co3O4 nanoparticles were synthesized by a one-step thermal treatment method. The microstructure and morphology of the samples were characterized by XRD, FT-IR, TEM, XPS and EIS. It is found that Co3O4 materials display chain structure and feature 70 nm particles in the diameter size. Interestingly, the chain structure feature of our Co3O4 materials improves electrode conductivity and carrier transportation with respect to polycrystal Co3O4. When calcined at 550 °C (Co3O4-550), the resulting sample displays good gas sensing performance for NOx at room temperature. Its measured gas sensitive response is 52.1% for 100 ppm NOx, and detection limit is lower than 100 ppb. The outstanding NOx gas sensing performance of the Co3O4-550 may be attributed to its unique chain structure. Tightly stucking particles and lower potential barrier are very beneficial to improve electrical properties of Co3O4-550, which is helpful to enhance its gas sensing performance.

In-depth understanding of interfacial behavior between biopolymer and semiconductor metal oxides is crucial to developing potential applications of their composites. A structure-ordered cellulose/zinc oxide composite was synthesized and systematically examined by a relativistic density functional theory. The prepared composite shows a hierarchical structure. ZnO nanoparticles of around 30 nm in size are found to uniformly grow along the cellulose fiber, which together construct the primary-structure unit. Associated with experimental characterizations, calculations unravel that the electrostatic attraction between cellulose and ZnO is the main driving force to form the primary structure and the subsequent electron transfer from cellulose to ZnO enhances their interfacial interaction; moreover, an exothermic process was computed. The interfacial interaction is mainly contributed by Zn-Oc (Oc denotes the cellulose oxygen atom), which is intrinsically of a dative bond; the interaction was calculated between −1.39 and −1.83 eV in strength and dominated by orbital attractions.

The Fe3O4/C/ZnO ternary composite has been synthesized by a facile one-pot method, in which lignin amine (LA) was used as carbon source as well as bridging ligand. Its structure, morphology and composition have been intensively characterized. The composite is found to be composed by cubic spinel Fe3O4, amorphous carbon and hexagonal wurtzite ZnO. Its morphology features as particles in the mean sizes of about 20 nm, which is larger than those of Fe3O4 and Fe3O4/ZnO. This case may be caused by the special construction of the resulting composite. Fe3O4 is covered by carbon, together forming particles; simultaneously, they interconnect with ZnO particles, leading to an increase in the particle size. With these peculiar structural characteristics, the synergistic effect is unraveled to enhance catalytic property of the composite while being applied in water treatment. Fe3O4/C/ZnO under both ultraviolet and visible light irradiation is found to show high degradation efficiencies. More importantly, the catalytic performance is very stable, maintaining 94% even after 5-cycle re-using test. Moreover, our composite materials also display excellent photocatalytic activities on degrading norfloxacin (NF) that is widely used as antibody. Due to easy recovery, good performance and facile synthetic route, our Fe3O4/C/ZnO is anticipated to have a good practical prospect in applications of water treatment.

In this work, highly dispersed and different morphologies of Co 3 O 4 on the surface of GO modified with polyethylenimine (PEI) were synthesized by hydrothermal method at different temperatures. Co 3 O 4 /PEI-GO exhibited better gas sensing properties for NO x gas than the pure Co 3 O 4 and Co 3 O 4 /GO. Especially, the Co 3 O 4 /PEI-GO composite with hydrothermal at 190 °C for 3 h showed excellent sensitive characteristics to NO x at room temperature. The cause of good gas sensing property come mainly from the synergy between Co 3 O 4 and graphene oxide (GO) modified with PEI, which can significantly enhance the gas sensing performance. The adsorption species of NO x on the surface of Co 3 O 4 /PEI-GO composite sensor was detectable by In Situ Diffuse Reflectance Infrared Transform Spectroscopy (DRIFT). The electronic core-shell configuration model has been established to illustrate the resistance change when the Co 3 O 4 is exposed to oxidizing gases. Hence, the Co 3 O 4 /PEI-GO composite materials are promising in application of detecting NO x gas sensing.