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A new family of indole-fused multi-resonance thermally activated delayed fluorescence materials have been developed, which exhibit narrowband blue emission with a small full width at half maximum of 22–23 nm. High maximum external quantum efficiencies of up to 16.8% have been achieved in organic light-emitting diodes. Furthermore, it is unveiled that peripheral substitutions can not only promote device efficiency but also help to maintain narrowband emission under high dopant concentrations. [ABSTRACT FROM AUTHOR]

Exploring highly efficient and durable bifunctional catalysts for enhancing overall water splitting (OWS) is greatly desired but challenging for electrocatalysis applications. Herein, Fe doping in three-dimensional (3D) tremella-like MoNi4 alloy crystal frameworks (denoted as MNFn CFs) is utilized for building up a bifunctional OWS electrocatalyst. Experimental analysis and density functional theory (DFT) simulations reveal that Fe doping enhances the conductivity, lowers the free energy barriers for water splitting, and weakens the adsorption of catalytic intermediates. In particular, a MNF2.5 CF catalyst exhibits a superior OER performance, and requires an ultra-low overpotential of 187.18 mV to drive 30 mA cm−2 and a low Tafel slope of 56.50 mV dec−1 in 1 M KOH. Eventually, an OWS device consisting of MNF2.5 CFs crystallized at 500 and 600 °C (MNF2.5-500‖MNF2.5-600 CFs) is demonstrated and can be driven by a 1.5 V AAA battery. [ABSTRACT FROM AUTHOR]

By employing aza[7]helicene as the chiral donor and triazine as the acceptor, we have developed a new type of circularly polarized luminescence material. The influence of the dihedral angle between the donor and acceptor moieties on the dissymmetry factors has been revealed for the first time, providing a novel strategy to amplify dissymmetry factors by engineering the dihedral angles in donor–acceptor type chiral materials. [ABSTRACT FROM AUTHOR]

Improving the intrinsic Na+ ion diffusivity of the advanced cathode material Na3V2(PO4)2O2F (NVPOF) has been a fundamental strategy to enhance its Na+ ion storage performance, while challenges remain in structural design and fabrication with specific features targeting the alleviation of migration energy barriers of the Na+ ions at different (de)sodiated states. Herein, K+ ions are introduced into the Na-sites in NVPOF to create Na+ ion vacancies, support the Na+ ion transport channels in the c axis and disrupt the continuity of the crystal structure. This strategy simultaneously reduces the electrostatic repulsive forces on the migrating Na+ ions from neighboring Na+ ions at a sodiated state and energy barriers originating from Na+ ion ordering at a desodiated state. Thus, the obtained NVPOF-K0.05 cathode presents a dramatic enhancement in the rate capability up to 80C (49.1 mA h g−1) and almost no decay in the long cycles at 10C up to 500 cycles (106.7 mA h g−1). The NVPOF-K0.05//Se@C sodium-ion full cell exhibits outstanding energy/power density (430.3 W h kg−1 at 208.3 W kg−1 and 310.5 W h kg−1 at 3357.1 W kg−1) and cycling stability (86.5% capacity retention of 107.1 mA h g−1 after 1000 cycles at 10C). [ABSTRACT FROM AUTHOR]

Addressing the structural instability and torpid kinetic limitation has been a pressing while challenging issue for vanadium oxide cathode materials to realize their outstanding performance in rechargeable aqueous zinc-ion batteries (ZIBs). Herein, vanadium oxide nanobelts with a bilayer structure (LiV3O8@NaV3O8, LVO@NVO) have been prepared successfully via a quick one-pot eutectic oxidation process. When evaluated as a cathode for ZIBs, the LVO@NVO shows an amazing capacity of 476 mA h g−1 at 0.05 A g−1, superior rate properties (236 mA h g−1 @ 5 A g−1), and excellent cycling capability over 2000 cycles with a capacity-retention of 93.4%. Owing to the pre-intercalated Li+ and Na+ cations and the resulting bilayer structure, higher pseudocapacitance, faster charge-transfer/ion-diffusion kinetics, and a robust architecture have been achieved in the LVO@NVO cathode, which are responsible for the superior zinc-ion storage performance. Furthermore, the energy storage mechanism based on Zn2+ and H+ co-intercalation/extraction has been proved. [ABSTRACT FROM AUTHOR]

In-plane micro-supercapacitors (MSCs) possess the capabilities of easy integration with planar circuits and feasible flexibility when they are used in flexible and wearable electronics. However, their unsatisfactory energy density limits their wide application. The Zn-ion hybrid supercapacitor is an ideal candidate as it assimilates the high energy-density of the zinc metal anode and high power-density of the pseudocapacitive material cathode. In view of the fact that multiple-metal MXenes could exhibit great potential compared to the single-metal MXenes in energy storage capability, here, Zn//V3CrC3Tx supercapacitors are fabricated. It is found that the partial replacement of Cr atoms for V atoms in V4C3Tx triggers an expansion of layer spacing of the MXene, the adsorption of Zn ions increases, and ion diffusion is promoted, which dramatically improve the capacitance, discharging potential, and cycle stability. Furthermore, in-plane Zn//V3CrC3Tx MSCs on paper demonstrate outstanding electrochemical properties and mechanical flexibility with an ultra-high area energy-density of 51.12 μW h cm−2, long cycle life of 20 000 cycles (84.5% capacitance retention), and outstanding bendability of 10 000 cycles (80.2% capacitance retention). The areal energy density and flexibility outperform most of the reported in-plane flexible MSCs. Owing to the emerging materials design and consummate flexible nature of the scheme, it can inject fresh strength into the development of flexible electronics. [ABSTRACT FROM AUTHOR]

The development of efficient and low-cost catalysts is of great significance for the future application of the electrocatalytic hydrogen evolution reaction (HER). Herein, a series of Ni,N co-doped Mo2C nanostructures (Nix–Mo2C/N) with different Ni content levels are fabricated. The phase-directing effect of Ni on Mo2C/N is observed, which is in charge of the phase transformation of Mo2C/N from an α- to a β-phase. At the optimized Ni-doping level, biphase Ni15–Mo2C/N exhibits outstanding HER activity under both acidic and alkaline conditions. In particular, under alkaline conditions, Ni15–Mo2C/N delivers an overpotential of only 105.0 mV, accompanied by a low Tafel slope of 44.96 mV dec−1. The performance is comparable to commercial 20% Pt/C and higher than most state-of-the-art Mo2C-based catalysts as well. [ABSTRACT FROM AUTHOR]

Although hydrated vanadate compounds have received extensive attention in aqueous batteries due to their high specific capacity, they are still impeded by the poor cycling resulting from host structure degradation and metal dendrite formation. Herein, we prepare multi-ion co-pre-intercalated hydrated vanadate microflowers (MxVO) with a robust crystal structure from vanadium slag waste, presenting highly reversible and ultrafast Zn2+ storage. Furthermore, using diethyl ether as the electrolyte additive, the cycling durability of zinc metal can be improved and the cells can work well at −20 °C. Impressively, the MxVO cathode realizes an unparalleled rate capability (203 mA h g−1 at 100 A g−1) and excellent cycling stability (317 mA h g−1 after 4000 cycles at 20 A g−1). Even when tested at −20 °C, it demonstrates a satisfactory zinc storage capability (e.g., the coin-type cell shows a discharge capacity of 120 mA h g−1 at 50 A g−1, and the pouch cell delivers ∼200 mA h g−1 at 1 A g−1). Hence, this work has exploited a new and efficient avenue for the exploration and utilization of solid waste toward high-performance aqueous batteries and other electrochemical applications. [ABSTRACT FROM AUTHOR]

Transition metal phosphide electrodes, particularly those with unique morphologies and micro-/nanostructures, have demonstrated desirable capabilities for hybrid supercapacitor applications by virtue of their superior electrical conductivity and high electrochemical activity. Here, three-dimensional hierarchical CoFeP@nickel–manganese sulfide nanoarrays were in situ constructed on a flexible carbon cloth via a hydrothermal method, a phosphorization process, followed by an electrodeposition approach. In this smart nanoarchitecture, CoFeP nanorods grown on carbon cloth act as the conductive core for rapid electron transfer, while the nickel–manganese sulfide nanosheets decorated on the surface of CoFeP serve as the shell for efficient ion diffusion, forming a stable core–shell heterostructure with enhanced electrical conductivity. Benefiting from the synergy of the two components and the generation of a heterointerface with a modified electronic structure, The CoFeP@nickel–manganese sulfide electrodes deliver a high capacity of 260.7 mA h g−1 at 1 A g−1, excellent rate capability, and good cycling stability. More importantly, an aqueous hybrid supercapacitor based on CoFeP@nickel–manganese sulfide as a positive electrode and a lotus pollen-derived hierarchical porous carbon as a negative electrode is constructed to display a maximum energy density of 60.1 W h kg−1 at 371.8 W kg−1 and a good cycling stability of 85.7% capacitance retention after 10 000 cycles. [ABSTRACT FROM AUTHOR]

In this article, a new zinc-containing ionic liquid (IL) [HMMIm]2[ZnCl4] (HMMIm = 1-hexyl-2,3-dimethyl-imidazolium) is designed, which acts as a multifunctional source for the interfacial engineering of ZnS nanodots (NDs). Given the electrostatic interaction driven by the imidazolium cation, the steric effect of the alkyl chain, and the in situ released Zn ion from the IL, [HMMIm]2[ZnCl4] shows great advantages in controlling the formation of ZnS NDs. Based on this strategy, a nanocomposite consisting of homodispersed ZnS NDs anchored on sulfur/nitrogen dual-doped reduced graphene oxide (ZnS-NDs@SNG) is prepared. When evaluated as an anode material for lithium-ion batteries (LIBs), the nanocomposite delivers high reversible specific capacity, excellent high-rate performance, and superior cycling life. In particular, a discharge capacity of 648.1 mA h g−1 can be achieved at a high current density (10.0 A g−1) over 5000 cycles. Benefitting from the multifunctional IL and the simple synthesis protocol, the IL-assisted interfacial engineering strategy will enable a new avenue for the controllable synthesis of metal-sulfide-based anode materials. [ABSTRACT FROM AUTHOR]

A series of hypercrosslinked polymers (P1 to P8) was synthesized from pyridine and conjugated monomers to support palladium for photocatalytic Suzuki–Miyaura coupling reactions. The results of SEM, TEM and XRD analyses reveal that the supports possess a loose porous amorphous lamellar structure, and the TGA test shows that they are thermally stable. Among the prepared photocatalysts, the one using P6 as a support performed the best, displaying excellent photocatalytic and recycling performance under the irradiation of blue light at 30 °C. [ABSTRACT FROM AUTHOR]

The intrinsically sluggish kinetics of the oxygen reduction reaction (ORR) and overuse of expensive and unstable Pt-based catalysts have severely hampered the development of clean energy technologies. Herein, a type of non-noble metal nanozyme as an ORR electrocatalyst, with Fe–Cu dual atomic sites embedded in three-dimensional porous N-doped carbon (FeCu-DA/NC), is fabricated by mimicking both the constituents of active centers and enzymatic microenvironment of Cytochrome c oxidase (CcO). The atomically dispersed Fe–Cu single atom sites are clearly identified by direct aberration-corrected transmission electron microscopy imaging, systematic X-ray absorption fine structure (XAFS) analyses, and density functional theory (DFT) calculations. FeCu-DA/NC exhibits a superior ORR activity, with about 30 mV more positive half-wave potential (E1/2) than that of commercial Pt/C catalysts in a base, and moreover with only an E1/2 gap of 20 mV to Pt/C in an acid. Importantly, FeCu-DA/NC displays an excellent durability under both acidic and basic conditions, which is much superior to that of Pt/C. DFT calculations further demonstrate that the enhanced performance can be attributed to the unique synergistic effect between Cu and Fe single atoms in which Cu–N4 serves as the electron donor to increase the electron density of the active centers of Fe–N4 and thus to facilitate O2 activation. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) provide the most efficient metal utilization for various catalytic reactions. Meanwhile, hierarchical pore structures play a decisive role in determining the catalytic activity of N-doped porous carbon materials, since normally micropores provide active locations and macro/mesopores serve as mass transport channels. However, it remains challenging to engineer highly dispersed SACs with hierarchical pore structures due to the complexity in synthesizing extra templates with controlled sizes and the possible exogenous impurities from templates. Herein, we develop a facile "confined recrystallization" self-template strategy to synthesize a hierarchical porous Fe SAC on N-doped carbon (Fe-NC SAC) with an iron mass loading of 1.5 wt%, by using polyvinylpyrrolidone (PVP), ferric nitrate and melamine. In this novel strategy, the introduced PVP can restrict the recrystallization of ferric nitrate owing to its large molecular weight. The formed nano-sized ferric nitrate crystals can not only serve as multifunctional self-templates to produce hierarchical pores, but also form atomically dispersed Fe–Nx sites through getting nitrogen from melamine. With the Fe-NC SAC as the catalyst, an excellent bifunctional ORR/OER performance and long-term durability superior to those of Pt/C and RuO2 are achieved in both liquid and solid Zn–air battery tests. Notably, in the flexible solid Zn–air battery, the Fe-NC SAC showed a high discharge voltage of 1.25 V and stable charge–discharge cycling at 1 mA cm−2 under different bending conditions. Further density functional theory (DFT) calculations showed that the ORR follows the association mechanism of O2 → *OOH → *O → *OH → OH−, while the OER goes on through the mechanism of OH− → *OH− → *O → *OOH → O2, with a low theoretical overpotential of 1.21 V on the Fe-NC SAC. This work not only provides a novel strategy to endow SACs with a hierarchical pore structure, but also represents an example of how to effectively investigate the correlation between the structure and catalytic activity of catalysts. [ABSTRACT FROM AUTHOR]

In past decades, with interest in wearable smart devices rapidly growing, the design and fabrication of novel energy storage devices have received increasing attention. Although secondary batteries are among the best options in this area, their bulky construction remains unable to fulfil the specific demands of miniaturization, portability, and flexibility. This review comprises a brief update on recent progress in printable secondary batteries, in combination with their principles and frequently used printing techniques. Moreover, we also discuss the challenges and advantages of printed secondary batteries and describe their future prospects in wearable smart devices. [ABSTRACT FROM AUTHOR]

In the search for more effective and stable fuel cell electrocatalysts, we have developed a facile method to synthesize novel Pd13Cu3S7 nanotubes (Pd13Cu3S7 NTs) for the first time. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) measurements have been used to characterize the structure, components and morphology of the Pd13Cu3S7 NTs. Due to their novel structure and composition, the as-prepared Pd13Cu3S7 NTs showed a high oxygen reduction reaction (ORR) catalytic performance, with similar catalytic activity to that of commercial Pt/C but with better stability than Pt/C. Furthermore, the ORR catalyzed by the Pd13Cu3S7 NTs was calculated to be a directly 4e− process. On the other hand, the Pd13Cu3S7 NTs also exhibited excellent ethanol oxidation reaction (EOR) activity (2.7 mA cm−2), which is about five times that of commercial Pd/C (0.55 mA cm−2). An EIS study indicated that the charge transfer resistance of the Pd13Cu3S7 NTs is much lower than that of commercial Pd/C in the EOR. [ABSTRACT FROM AUTHOR]

Small carbon nanoparticles are an emerging member of the carbonaceous nanomaterial family and have been subsequently named as “carbon quantum dots” or “carbon nanodots”. Generally, carbon quantum dots are a type of spherical or sphere-like nanoparticles of less than 10 nm in size. Due to their unique properties, for example, size-dependent fluorescence, non-toxicity, biocompatibility, and easy accessibility, carbon quantum dots possess a great many potential applications in a range of fields from chemical sensing and imaging to catalysis and drug delivery, and thus are appealing to a number of researchers in nanoscience and nanotechnology. In this review, we give a brief introduction of the synthesis and fundamental properties of carbon quantum dots, then present their applications in metal ion sensing in detail along with illustrating the related mechanisms, and finally come up with some challenges currently faced and future outlooks for this fascinating carbon material. We hope this review could be helpful for readers who are preparing to join and/or have joined the research field of carbon quantum dots. [ABSTRACT FROM AUTHOR]

Ionothermal syntheses, characterization and properties of two selenidostannate compounds with two- or three-dimensional (D) skeletons by utilizing the synergistic structure-directing effects of the ionic liquid (IL) [Bmmim]Cl (Bmmim = 1-butyl-2,3-dimethylimidazolium) and in-situ generated metal–amine complexes (MACs), namely, 2D-(Bmmim)2[Ni(teta)(en)][Sn3Se7]2 (1, teta = triethylenetetramine, en = ethylenediamine) and 3D-(Bmmim)1.5(dienH)0.5Ni(dien)2[Sn4Se9]2 (2, dien = diethylenetriamine) are presented. Single-crystal X-ray diffraction analyses revealed that compound 1 possesses a lamellar anionic [Sn3Se7]n2n− structure comprising a large ten-membered ring with a window size of 24.85 × 13.38 Å when considering the [Sn3Se4] semicube as a member. While 2 features a 3D [Sn4Se9]n2n− framework with orthogonally intersecting channels where the three different types of cations are filled. The successful isolation of these two compounds demonstrated again that the mixed SDA strategy is promising for the synthesis of novel crystalline selenidostannates. [ABSTRACT FROM AUTHOR]

A new magnesium coordination polymer (Mg-CP), namely [Bmim]2[Mg6(NDC)5(HNDC)2(HCOO)2] (1, H2NDC = 1, 4-naphthalenedicarboxylic acid, [Bmim] = 1-butyl-3-methyl-imidazolium ion), has been ionothermally synthesized and structurally characterized. Single-crystal X-ray structural determination indicated that the title compound possessed an anionic three-dimensional (3D) framework constructed by the interconnections of unprecedented hexanuclear magnesium-carboxylate clusters as secondary building units (SBUs) via bridging NDC ligands. Compound 1 exhibited blue luminescence emission at 440 nm when excited at 360 nm. Significantly, the title non-porous Mg-CP could be utilized as a precursor for preparing porous carbons through thermal decomposition in optimized conditions. Different from the reported high decomposition temperature (＞1000 °C) mostly based on porous Zn-CP precursors, the optimum decomposition temperature for 1 was only 700 °C, and the resulting porous carbons showed 465 cm3 g−1 adsorption volume for N2. The as-prepared carbon exhibited finely selective N2 adsorption ability over H2 and CO2. This work may provide a certain guiding significance for exploiting ionothermally synthesized Mg-CPs as a new type of precursor towards porous carbons. [ABSTRACT FROM AUTHOR]

Presented are the syntheses, characterizations and properties of a series of selenidostannate compounds directed by metal–amine complex (MAC) cations and/or [Bmmim]+ (Bmmim = 1-butyl-2,3-dimethylimidazolium). Mixtures of the ionic liquid (IL) (Bmmim)Cl and amines, such as ethylenediamine (en) and diethylenetriamine (dien), in various ratios were used to ionothermally/solvothermally prepare four selenidostannates, namely, [Mn(en)3]Sn3Se7 (1), [Mn(dien)2]Sn3Se7·H2O (2), (Bmmim)3[Mn(en)3]2[Sn9Se21]Cl (3) and (Bmmim)6[Mn(dien)2]2Sn15Se35 (4). Single-crystal X-ray diffraction analyses revealed that these compounds exhibit lamellar anionic [Sn3Se7]n2n− structures. [Sn3Se7]n2n− layers in all 1–4 possess a {63} net, considering [Sn3Se10] semi-cube unit as a 3-connected node; however, diverse multi-membered rings exist there. In compounds 1 and 2, all the [Sn3Se10] units are 3-connected nodes interlinking with each other via edge-sharing two Se atoms to produce six-membered rings. However, in compound 3, the insertion of two [Sn3Se9] units into a six-membered ring results in a novel eight-membered heart-shaped ring, which has never been observed before in the family of chalcogenidostannates. More interestingly, the [Sn3Se7]n2n− layer in compound 4 consists of mixed six- and eight-membered rings. The phase composition is strongly dependent on the ratio of IL to MAC in the syntheses, e.g., 1 and 2 were obtained with IL : MAC ratios less than 3 : 1 and 4 : 1, while 3 and 4 were obtained when the ratios were increased to 4 : 1 and 5 : 1, respectively. The structural variation from 1 to 4 clearly indicates the competitive and synergistic effects between MAC and IL cation on the formation of lamellar selenidostannates. A synthetic approach via varying the ratio of IL to MAC cation as solvent and structure-directing agent will be attractive in the synthesis of novel chalcogenidometallates. [ABSTRACT FROM AUTHOR]

The removal of highly radioactive and long-lived 137Cs+ and 90Sr2+ from solution is of significance for radionuclide remediation. Herein we prepared a two-dimensionally microporous thiostannate, namely (Me2NH2)4/3(Me3NH)2/3Sn3S7·1.25H2O (FJSM-SnS), and systematically investigated its Cs+ and Sr2+ ion-exchange performance in different conditions. The structural stabilities and variation, ion-exchange kinetic and isothermal behavior, pH-dependent distribution coefficients (Kd), ion-exchange in simulated groundwater and ion-exchange applied to chromatography have been investigated. The results indicated that the maximum Cs+ and Sr2+ ion-exchange capacities of FJSM-SnS were 408.91 mg g−1 and 65.19 mg g−1, respectively. In particular, FJSM-SnS showed quick ion-exchange ability and wide pH resistance (0.7–12.7) which make it outstanding among the ion-exchangers. An ion-exchange chromatographic column was firstly studied for chalcogenido ion-exchange materials, that is, a column filled with 3.0 g FJSM-SnS could remove 96–99% of Cs+ ion and near 100% of Sr2+ ion at low ionic concentrations in 900 bed volumes solutions. Furthermore, the title material could be synthesized on a large scale by a facile, one-pot and economical solvothermal method. The relatively low cost but remarkable ion-exchange performance makes it promising for radionuclide remediation. [ABSTRACT FROM AUTHOR]

Flower-like Ni-Pt nanoclusters assembled on graphene have been facilely synthesized by a co-reduction route. Thanks to the unique structure and strong interaction with graphene, the as-synthesized Ni3Pt7/graphene nanoclusters exhibit 100% hydrogen selectivity and exceedingly high activity toward hydrogen generation from alkaline solution of hydrazine at room temperature. [ABSTRACT FROM AUTHOR]

A new thiogermanate–thioantimonate, namely, [AEPH2][GeSb2S6]·CH3OH (1) (AEP = N-(2-aminoethyl)piperazine) has been solvothermally synthesized, whose structure features a one-dimensional anionic ribbon of [GeSb2S6]n2n− built of the firstly observed tetranuclear {GeSb3S11} cluster as secondary building unit. The photocatalytic study indicated that 1 was able to degrade Rhodamine B under visible irradiation. [ABSTRACT FROM AUTHOR]

Diblock copolymers of poly(ethylene glycol) (PEG) and biodegradable 2-(diisopropylamino)ethanol grafted poly(l-aspartic acid) (PAsp(DIP)) were synthesized and evaluated as a MRI-visible and pH-sensitive drug delivery system. The copolymers can self-assemble into stable vesicles in aqueous solutions at neutral pH, resembling the physiological environment, whereas they disassemble in acidic endosomal/lysosomal compartments of tumor cells to achieve rapid drug release. The anticancer drug doxorubicin (DOX) and hydrophilic superparamagnetic iron oxide nanoparticles (SPIONs) were encapsulated inside the inner aqueous core of the vesicles for cancer therapy and MR imaging, respectively. In vitrodrug release studies showed that the DOX release from the pH-sensitive vesicles was significantly faster at pH 5.0 than at pH 7.4. SPIONs clustering inside the inner aqueous core of the vesicles resulted in a high spin–spin (T2) relaxivity. Cell culture studies showed that the DOX-SPION-loaded vesicles could be effectively internalized by human hepatic cancer Bel 7402 cells, and DOX could be rapidly released from vesicles inside lysosomal compartments and then migrated into nuclei. Consequently effective suppression of cancer cell growth was detected. This study demonstrated the potential of the biodegradable DOX-SPION-loaded pH-sensitive vesicles as an effective multifunctional nanomedicine platform for cancer therapy due to their pH-triggerable drug release and high MRI sensitivity. [ABSTRACT FROM AUTHOR]

Copolymers of poly(ethylene glycol) and poly(-caprolactone) bearing folate as a targeting molecule, i.e.Fa–PEG–PCL, are synthesized and employed to encapsulate nonclustered superparamagnetic iron oxide nanoparticle (SPION) to achieve a water-dispersible and tumor-targeted MRI contrast agent. Compared to the water-soluble SPIONs prepared by small molecular surfactant coating, the nonclustered SPIO-encapsulated PEG–PCL micelles (PEG–PCL–SPIONs) simultaneously display increased transversal (r2) and much decreased longitudinal (r1) magnetic resonance relaxivities, leading to high r2/r1ratios which make PEG–PCL–SPIONs highly sensitive MRI T2contrast agents. Animal experiments are carried out by injecting the micelle solutions viaa tail vein into nude mice bearing subcutaneous xenografts of human Bel 7402 hepatoma. Notably, the nonclustered SPIO-encapsulated micelles measuring 35 nm on average based on PEG4.3k–PCL1k display much slower liver accumulation implying prolonged circulation, compared to the clustered SPIO-encapsulated micelles (125 nm) based on PEG4.3k–PCL7.2k. Furthermore, injection of the small-sized and folate-targeted micelle, i.e.Fa–PEG4.3k–PCL1k–SPION, result in obviously shortened MRI T2as well as much decreased MRI signal intensity within the tumor section, implying efficient accumulation of the micelles which is also demonstrated by prussian blue staining of the tumor tissue. Our results reveal the great potential of the nonclustered SPIO-encapsulated and small-sized micelle with active tumor-targeting function as an effective MRI probe for in vivotumor detection. [ABSTRACT FROM AUTHOR]

Presented here are the ionothermal preparation and structural variation of selenidostannates, whose structures can be tuned by varying the combination of ionic liquids and auxiliary amines as mixed solvent, as well as changing the reaction temperature and time. Remarkably, a silver-selenidostannate compound featuring lamellar structure was achieved by unusual insertion of linear two-coordinate Ag+ ions between the {Sn3Se7}n2n− double chains. [ABSTRACT FROM AUTHOR]

The development of efficient and low-cost catalysts is of great significance for the future application of the electrocatalytic hydrogen evolution reaction (HER). Herein, a series of Ni,N co-doped Mo 2 C nanostructures (Ni x -Mo 2 C/N) with different Ni content levels are fabricated. The phase-directing effect of Ni on Mo 2 C/N is observed, which is in charge of the phase transformation of Mo 2 C/N from an α - to a β -phase. At the optimized Ni-doping level, biphase Ni 15 -Mo 2 C/N exhibits outstanding HER activity under both acidic and alkaline conditions. In particular, under alkaline conditions, Ni 15 -Mo 2 C/N delivers an overpotential of only 105.0 mV, accompanied by a low Tafel slope of 44.96 mV dec -1 . The performance is comparable to commercial 20% Pt/C and higher than most state-of-the-art Mo 2 C-based catalysts as well.

The memristor is a promising candidate to implement high-density memory and neuromorphic computing. Based on the characteristic retention time, memristors are classified into volatile and non-volatile types. However, a single memristor generally provides a specific function based on electronic performances, which poses roadblocks for further developing novel circuits. Versatile memristors exhibiting both volatile and non-volatile properties can provide multiple functions covering non-volatile memory and neuromorphic computing. In this work, a versatile memristor with volatile/non-volatile bifunctional properties was developed. Non-volatile functionality with a storage window of 4.0 × 10 5 was obtained. Meanwhile, the device can provide threshold volatile functionalities with a storage window of 7.0 × 10 4 and a rectification ratio of 4.0 × 10 4 . The leaky integrate-and-fire (LIF) neuron model and artificial synapse based on the device have been studied. Such a versatile memristor enables non-volatile memory, selectors, artificial neurons, and artificial synapses, which will provide advantages regarding circuit simplification, fabrication processes, and manufacturing costs.

Transition metal phosphide electrodes, particularly those with unique morphologies and micro-/nanostructures, have demonstrated desirable capabilities for hybrid supercapacitor applications by virtue of their superior electrical conductivity and high electrochemical activity. Here, three-dimensional hierarchical CoFeP@nickel-manganese sulfide nanoarrays were in situ constructed on a flexible carbon cloth via a hydrothermal method, a phosphorization process, followed by an electrodeposition approach. In this smart nanoarchitecture, CoFeP nanorods grown on carbon cloth act as the conductive core for rapid electron transfer, while the nickel-manganese sulfide nanosheets decorated on the surface of CoFeP serve as the shell for efficient ion diffusion, forming a stable core-shell heterostructure with enhanced electrical conductivity. Benefiting from the synergy of the two components and the generation of a heterointerface with a modified electronic structure, The CoFeP@nickel-manganese sulfide electrodes deliver a high capacity of 260.7 mA h g -1 at 1 A g -1 , excellent rate capability, and good cycling stability. More importantly, an aqueous hybrid supercapacitor based on CoFeP@nickel-manganese sulfide as a positive electrode and a lotus pollen-derived hierarchical porous carbon as a negative electrode is constructed to display a maximum energy density of 60.1 W h kg -1 at 371.8 W kg -1 and a good cycling stability of 85.7% capacitance retention after 10 000 cycles.

In this article, a new zinc-containing ionic liquid (IL) [HMMIm] 2 [ZnCl 4 ] (HMMIm = 1-hexyl-2,3-dimethyl-imidazolium) is designed, which acts as a multifunctional source for the interfacial engineering of ZnS nanodots (NDs). Given the electrostatic interaction driven by the imidazolium cation, the steric effect of the alkyl chain, and the in situ released Zn ion from the IL, [HMMIm] 2 [ZnCl 4 ] shows great advantages in controlling the formation of ZnS NDs. Based on this strategy, a nanocomposite consisting of homodispersed ZnS NDs anchored on sulfur/nitrogen dual-doped reduced graphene oxide (ZnS-NDs@SNG) is prepared. When evaluated as an anode material for lithium-ion batteries (LIBs), the nanocomposite delivers high reversible specific capacity, excellent high-rate performance, and superior cycling life. In particular, a discharge capacity of 648.1 mA h g -1 can be achieved at a high current density (10.0 A g -1 ) over 5000 cycles. Benefitting from the multifunctional IL and the simple synthesis protocol, the IL-assisted interfacial engineering strategy will enable a new avenue for the controllable synthesis of metal-sulfide-based anode materials.

Herein, for the first time, we find that the surface mass transport properties of catalysts play critical roles in determining the electrocatalytic NRR selectivity over the competitive HER in aqueous media on metallic Cu. In particular, by controlling the monolayer thickness of Cu nanoparticles with a minimum mass transport barrier, the faradaic efficiency (FE) of the NRR can be dramatically enhanced to 33% in the H-type cell test and even to 59% in a new-type Zn-N 2 aqueous battery.

Ionothermal syntheses, characterization and properties of two selenidostannate compounds with two- or three-dimensional (D) skeletons by utilizing the synergistic structure-directing effects of the ionic liquid (IL) [Bmmim]Cl (Bmmim = 1-butyl-2,3-dimethylimidazolium) and in-situ generated metal-amine complexes (MACs), namely, 2D-(Bmmim)2[Ni(teta)(en)][Sn3Se7]2 (1, teta = triethylenetetramine, en = ethylenediamine) and 3D-(Bmmim)1.5(dienH)0.5Ni(dien)2[Sn4Se9]2 (2, dien = diethylenetriamine) are presented. Single-crystal X-ray diffraction analyses revealed that compound 1 possesses a lamellar anionic [Sn3Se7]n(2n-) structure comprising a large ten-membered ring with a window size of 24.85 × 13.38 Å when considering the [Sn3Se4] semicube as a member. While 2 features a 3D [Sn4Se9]n(2n-) framework with orthogonally intersecting channels where the three different types of cations are filled. The successful isolation of these two compounds demonstrated again that the mixed SDA strategy is promising for the synthesis of novel crystalline selenidostannates.

Presented are the syntheses, characterizations and properties of a series of selenidostannate compounds directed by metal-amine complex (MAC) cations and/or [Bmmim](+) (Bmmim = 1-butyl-2,3-dimethylimidazolium). Mixtures of the ionic liquid (IL) (Bmmim)Cl and amines, such as ethylenediamine (en) and diethylenetriamine (dien), in various ratios were used to ionothermally/solvothermally prepare four selenidostannates, namely, [Mn(en)3]Sn3Se7 (1), [Mn(dien)2]Sn3Se7·H2O (2), (Bmmim)3[Mn(en)3]2[Sn9Se21]Cl (3) and (Bmmim)6[Mn(dien)2]2Sn15Se35 (4). Single-crystal X-ray diffraction analyses revealed that these compounds exhibit lamellar anionic [Sn3Se7]n(2n-) structures. [Sn3Se7]n(2n-) layers in all 1-4 possess a {6(3)} net, considering [Sn3Se10] semi-cube unit as a 3-connected node; however, diverse multi-membered rings exist there. In compounds 1 and 2, all the [Sn3Se10] units are 3-connected nodes interlinking with each other via edge-sharing two Se atoms to produce six-membered rings. However, in compound 3, the insertion of two [Sn3Se9] units into a six-membered ring results in a novel eight-membered heart-shaped ring, which has never been observed before in the family of chalcogenidostannates. More interestingly, the [Sn3Se7]n(2n-) layer in compound 4 consists of mixed six- and eight-membered rings. The phase composition is strongly dependent on the ratio of IL to MAC in the syntheses, e.g., 1 and 2 were obtained with IL:MAC ratios less than 3:1 and 4:1, while 3 and 4 were obtained when the ratios were increased to 4:1 and 5:1, respectively. The structural variation from 1 to 4 clearly indicates the competitive and synergistic effects between MAC and IL cation on the formation of lamellar selenidostannates. A synthetic approach via varying the ratio of IL to MAC cation as solvent and structure-directing agent will be attractive in the synthesis of novel chalcogenidometallates.

The bpy, dpe and dppe were introduced as auxiliary ligands, respectively, to construct three magnesium-1,4-NDC coordination polymers (Mg-CPs) that exhibited tunable photoluminescence (PL) and direct white-light emission upon varying the excitation light.

Wavy palladium (Pd) nanorods were obtained by controlled synthesis by using amine-boranes as the reducing agents. Thanks to the unique structure and strong interaction with graphene, the as-synthesized Pd nanorods supported on graphene exhibit much enhanced electrocatalytic activity towards formic acid oxidation as compared with Pd nanoparticles.

Presented here are three organic-decorated manganese selenidostannates with various structural dimensionalities (D), namely, 1D – SnSe3Mn(en)2 (en = ethylenediamine) (1), 2D – SnSe3Mn(en) (2) and 3D – MnSnSe4Mn(en)2 (3). 2 and 3 represent the first 2D and 3D organic-decorated Mn–Sn–Se compounds, respectively. A structural transformation was observed between 1 and 2.

Two mixed-valent thioarsenates, namely (enH2)(4.5)[In(As(V)S4)3][As2(III)(μ-S2)S3]Cl (1) and (enH2)MnAs(III)As(V)S6 (2) (en = ethylenediamine), have been solvothermally synthesized and characterized. Thermal stability, magnetic and mixed-valent optical properties, as well as theoretical band structures and DOSs, of 1 and 2 have also been studied.

Considerable areal capacitance (mF cm(-2) level) and long cycling stability (2000 cycles, the best ever for Fe(3)O(4)-based electrodes) are demonstrated for the first time for Fe(3)O(4)@SnO(2) core-shell nanorod film, which is grown directly on a current collector substrate.