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Hydrophobic membranes infused with mixed solvents including a low polar solvent and a specific solvent can efficiently separate analytes from blood upon applying a voltage. In contrast, membranes infused with a specific solvent alone show significantly reduced separation efficiencies for blood samples. Infusion of a low polar solvent is of importance for achieving antifouling ability of membranes for biological sample pretreatment. [ABSTRACT FROM AUTHOR]

The availability of catalytic sites for contact with reactants is a key issue to improve the performance of a catalyst, where constructing hollow structured nanomaterials has been considered as an effective strategy. Here, an N-doped carbon supported Ru catalyst with an interior cavity was synthesized by etching a MOF-derived core–shell precursor, in which metal Ru can be highly dispersed in the porous shell. This catalyst shows 98.7% conversion and >99% selectivity towards p-chloroaniline in the hydrogenation of p-chloronitrobenzene, which is better than the corresponding supported catalyst. Moreover, it also displays excellent stability with 5 cycle runs and good substrate universality for the hydrogenation of extensive substituted nitroarenes. Various characterization techniques and control experiments reveal the advantage of the unique structure to promote the mass transport and adsorption of reactant molecules on Ru sites. This work provides a novel strategy to design an efficient Ru-based catalyst for chemoselective hydrogenation. [ABSTRACT FROM AUTHOR]

Copper ions (Cu2+) play an essential role in various cellular functions, including respiration, nerve conduction, tissue maturation, oxidative stress defense, and iron metabolism. Covalent organic frameworks (COFs) are a class of porous crystalline materials with directed structural designability and high stability due to the combination of different monomers through covalent bonds. In this study, we synthesized a porphyrin-tetrathiazole COF (TT-COF(Zn)) with Zn-porphyrin and tetrathiafulvalene (TTF) as monomers and used it as a photoactive material. The strong light absorption of metalloporphyrin and the electron-rich properties of supplied TTF contribute to its photoelectrochemical performance. Additionally, the sulfur (S) in the TTF can coordinate with Cu2+. Based on these properties, we constructed a highly sensitive photoelectrochemical sensor for detecting Cu2+. The sensor exhibited a linear range from 0.5 nM to 500 nM (R2 = 0.9983) and a detection limit of 0.15 nM for Cu2+. Notably, the sensor performed well when detecting Cu2+ in water samples. [ABSTRACT FROM AUTHOR]

The constrained enzymatic activity and aggregation challenges encountered by small-sized nanozymes pose obstacles to their practical utility, necessitating a strategy to mitigate aggregation and boost enzymatic catalytic efficiency. In this work, a negatively charged Eu MOF was utilized as the encapsulation matrix, encapsulating the small-sized nanozymes FeNCDs into the Eu MOF to synthesize an FeNCDs@Eu MOF. The dispersibility of the encapsulated FeNCDs was increased, and owing to the negative charge of the FeNCDs@Eu MOF, electrostatic pre-concentration of the positively charged target molecule tetracycline (TC) was facilitated, thereby amplifying the enzymatic catalytic efficiency of the FeNCDs. The response of the FeNCDs to TC increased by nearly 6 times upon encapsulation. The TC detection limit (LOD) of the FeNCDs@Eu MOF-based sensor is as low as 11.63 nM. The incorporation of fluorescence detection expanded the linear range of the sensor, rendering it more suitable for practical sample detection. [ABSTRACT FROM AUTHOR]

Organic dye pollutants have become a major concern owing to their harmful nature to the environment, and removing and separating them should be one of the best remedies. Herein, two two-dimensional (2D) Cu-based coordination polymers (CPs) [Cu(3-dpye)(OX)]n (Cu-CP-1) and [Cu(3-dpyb)(OX)]n (Cu-CP-2) [3-dpye = N,N′-bis(3-pyridinecarboxamide)-1,2-ethane, 3-dpyb = N,N′-bis(3-pyridinecarboxamide)-1,4-benzene, OX = oxalate] were successfully synthesized by tuning the secondary ligands under hydrothermal conditions and applied to selectively adsorb and photodegrade anionic dyes, such as methyl orange (MO) and Congo red (CR), from an aqueous solution. The Cu-CPs exhibited different compositions because of the different N-donor ligands, which were used as precursors for the preparation of Cu/Cu2O heterojunctions (Cu@C-1, Cu@C-2, Cu@N-1, Cu@N-2, Cu@S-1 and Cu@S-2). Doping a foreign element into the intrinsic Cu-based materials is an effective way to enhance both the adsorbing capacity and the photocatalytic activity. Benefiting from the formation of Cu/Cu2O and graphite-type carbon sheets, the maximum adsorption capacities of Cu@N-2 at room temperature are 2097.84 mg g−1 for MO and 1942.85 mg g−1 for CR in 240 min, while the photocatalytic degradation rates are 95.23% for MO and 99.25% for CR after 4 h. [ABSTRACT FROM AUTHOR]

We synthesized tetrasubstituted olefins regioselectively and stereoselectively from ynamides and internal alkynes with sulfonyl iodides under blue LEDs in few minutes. The key features are being metal-free, easy to handle, simple, broad in scope, and environmentally friendly. Furthermore, a gram-scale experiment was conducted, and the synthesized corresponding sulfonyl-iodinated products were smoothly altered into various other products. [ABSTRACT FROM AUTHOR]

To develop high-performance low-Pt electrocatalysts for direct alcohol fuel cells (DAFCs), we herein propose an interfacial engineering strategy, using interfacial Ag nanowire arrays as a sacrificing template and successfully fabricating a AgPtAu nanotrough array catalyst at water/air interfaces. By adjusting the conditions of interfacial reaction, composition-varied AgPtAu nanotrough arrays can be easily obtained. The formation of a trough-like morphology of AgPtAu can be attributed to the interface-confined Ag nanowire arrays reacting successively with PtCl62− and AuCl4− in the water phase. Optimized surface-Pt-rich Ag11Pt5Au84 nanotrough arrays exhibit ∼2270 and ∼2290 mA mgAu+Pt−1 in the mass activity towards methanol and ethanol electrooxidation, respectively, ∼3 times better than that of commercial Pt/C, and show improved tolerance towards CO-like carbonaceous intermediates. This work suggests that properly combining the positive catalytic effects of morphology and composition may be a possible avenue to tackle the issue of low-Pt electrocatalysts for DAFCs. [ABSTRACT FROM AUTHOR]

In this work, three commercial Cu catalysts were benchmarked in the CO2RR using a gas-diffusion type microfluidic flow electrolyzer. We showed that commercial Cu could deliver a high FE of near 80% for C2+ product formations at 300 mA cm−2. By tuning the catalyst loading, a high reaction rate of near 1 A cm−2 with a C2+ product FE over 70% was achieved. Our results demonstrated that commercial Cu could achieve similar or better performances compared to many current catalysts by design in the CO2RR using similar electrolyzers. In addition, we showed that high CO reduction reaction (CORR) performance could also be achieved on commercial Cu, and disparities between CO and CO2 electrolysis were discussed. [ABSTRACT FROM AUTHOR]

Cellulose aerogels were synthesized to be used for urea adsorption and targeting a fast adsorption rate and high adsorption capacity. This kind of urea adsorbent was synthesized by a sol–gel method in a simple NaOH/urea aqueous solution system. The aerogels were characterized by FT-IR spectroscopy, XRD, SEM, and N2 adsorption/desorption techniques and their adsorption properties were evaluated. The results showed that the aerogels comprised an ultralight mesoporous material with a large specific surface area and a porous three-dimensional network structure. The adsorption process followed the Freundlich model and the pseudo-first-order kinetic model. The synthesized aerogels had a superior adsorption capacity and a fast adsorption rate, and adsorption equilibrium could be reached within 60 min under the human physiological temperature. Therefore, this aerogel type of absorbent has potential applications for the adsorption of urea in dialysate. [ABSTRACT FROM AUTHOR]

Since the famous Swedish chemist Scheele described molybdenum blue for the first time in 1778, polyoxometalate (POM) chemistry has made significant progress in its more than 200-year history. Compared with the POM chemistry of Mo, W and V, significant improvement of polyoxotantalates (POTas) occurred mainly during the last few years. In this paper, complexes with different structures, including isopolyoxotantalates (IPOTas), organic–inorganic hybrid POTas, Ta/W mixed POMs and heteropolyoxotantalates (HPOTas) with their derivatives, are reviewed, aiming at providing some useful guidance for further exploration and discovery of more exciting POTas with innovative architectures and excellent performances. Herein, we highlight and discuss the structural features of POTas according to various structural types. In addition, the synthesis strategies and related applications, especially in photocatalysis, are reviewed. [ABSTRACT FROM AUTHOR]

Homo-valent diruthenium(II , II) carbonates have been underexplored hitherto. This paper reports the synthesis and crystal structure of a diruthenium(II , II) compound, Na4Ru2(CO3)4·10H2O (1). It has a two-dimensional structure in which the paddle-wheel diruthenium units of Ru2(CO3)44− are cross-linked through the carbonate groups. The investigation of the primary magnetic properties and theoretical studies with density functional theory (DFT) reveal that weak antiferromagnetic interactions are propagated between the Ru2 units which contain two unpaired electrons in an electron configuration σ2π4δ2π*2δ*2 with a ground state S = 1. According to Raman spectrum measurements combined with theoretical calculations, the strong peak at 356 cm−1 in the small-wavenumber region was assigned to the stretching of the Ru–Ru double bonds. [ABSTRACT FROM AUTHOR]

Herein, a Co–Fe Prussian blue analogue nanocube (Co–Fe PBA NC) was prepared in situ via a simple and rapid coprecipitation method at room temperature, and the synthesized nanocube was systematically characterized. The Co–Fe PBA NC was proven to have intrinsic oxidase-like activity, which can catalyze the production of reactive oxygen species, such as superoxide anions (O2˙−), hydroxyl radicals (˙OH), and singlet oxygen (1O2), in a dissolved oxygen system without the presence of hydrogen peroxide (H2O2). By making full use of the oxidase-like activity of the Co–Fe PBA NC and using the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB), a colorimetric sensor was fabricated for the detection of ascorbic acid (AA) and its related biological enzymes' activities, including alkaline phosphatase (ALP), α-glucosidase (α-Glu), and ascorbic acid oxidase (AAO), in human serum. This study presents an oxidase mimic that can be synthesized via a simple, rapid, and low-cost method, which overcomes the defects of cumbersome and time-consuming synthetic process, dependence on professional instruments and high cost of some previously reported nanozymes. In addition, this study provides a new multifunctional colorimetric sensing platform for AA and its related biological enzymes, showing great potential in biological assays. [ABSTRACT FROM AUTHOR]

Major advances in molecular detection are being driven by goals associated with the development of methods that are amenable to miniaturization and automation, and that have high sensitivity and low interference. The new detection methods are confronted by many interfacial issues, which when properly addressed can lead to improved performance. One interfacial property, special wettability, can facilitate precise delivery and local enrichment of molecules to sensing elements. This review summarizes applications of unique features of special wettability in molecular detection including (1) chemical and electrochemical reactions in anchored microdroplets on superwetting surfaces, (2) enrichment of analytes and active materials at low contact areas between droplets and superwetting surfaces, (3) complete opposite affinities of superwetting surfaces toward nonpolar/polar solutes and oil/water phases, and (4) directional droplet transportation on asymmetric superwetting surfaces. The challenges and opportunities that exist in design and applications of special wettability in interfacial delivery and enrichment for detection of a few molecules are also discussed. [ABSTRACT FROM AUTHOR]

An unprecedented DMAP-catalysed amidation of aryl and alkyl carboxylic acids with organo-cyanamides has been developed. Unlike the use of N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) as an electrophilic cyanating reagent, an unusual desulfonylation/decyanation reaction model has been disclosed for the first time. Remarkable features of this reaction include readily available substrates, simple operation and broad scope, enabling the efficient synthesis of structurally diverse amides. The synthetic utility of this protocol was demonstrated by the late-stage amidation of bioactive carboxylic acids and a scale-up reaction. [ABSTRACT FROM AUTHOR]

The urea oxidation reaction (UOR), which possesses a low theoretical potential and superior kinetics, is an attractive substitute for the anodic oxygen evolution reaction (OER) in overall water splitting; however, the implementation of hydrogen production in overall urea splitting is impeded by the deficiency of highly efficient, durable and cost-effective catalysts. Herein, we fabricated an Ni2P–MoP2 heterostructure with a hierarchical structure grown on carbon paper (Ni–Mo–P/CP), which exhibited robust activity and outstanding durability for the electrocatalytic oxidation of urea. The Ni–Mo–P/CP catalyst possessed an ultralow potential of 1.39 V to obtain the current density of 100 mA cm−2, small Tafel slope (27 mV dec−1) and long-term durability with almost no decay within 15 h. The experimental characterization revealed that the optimized electronic structure and the synergistic effect of abundant exposed active sites in the Ni–Mo–P/CP catalyst contribute to the efficient UOR catalytic activity. This work enriches the candidate catalysts for the UOR and promotes the industrial development of hydrogen production. [ABSTRACT FROM AUTHOR]

In this paper, the effects of Zr, Al or Sr doped Mn/MCM-41 on NH3-SCR activity, SO2/H2O resistance and mechanism were studied. The results showed that Mn/Zr-MCM-41 has 100% NOx conversion at 175–300 °C while Mn/Al-MCM-41 achieves about 94% N2 selectivity at 120–400 °C. Zr doping significantly enhances the resistance to SO2 at 200 °C while Sr plays a negative role. Doped metal does not change the ordered hexagonal arrangement of MCM-41, but can cause the specific surface area enrichment of Mn while Al doping leads to the entry of Mn into the channel of MCM-41. Mn/MCM-41 has only Lewis acid sites, but Zr, Al or Sr doped catalysts have Lewis and Brønsted acid sites. Moreover, the reaction path on Mn/MCM-41 and Mn/Zr-MCM-41 mainly conforms to the L–H mechanism while Mn–Al or Mn–Sr doped catalysts follow L–H and E–R mechanisms. However, the deposited sulfates change the progress of the NH3-SCR process and cause a decline of SCR activity. [ABSTRACT FROM AUTHOR]

The replacement of traditional incandescent, halogen and fluorescent lamps by white light emitting diodes (WLEDs) is expected to reduce the global electricity consumption by one-third by 2030, according to the US Department of Energy. The current WLED technology uses rare-earth element (REE) based phosphor materials, which, not only is cost-intensive but also constitutes an environmental concern. Hence, researchers are in a quest for a new-generation of opto-electronic materials that can replace the conventional phosphors in WLEDs and thus aim towards a cleaner and more energy efficient lighting technology for the future. Luminescent metal–organic frameworks (LMOFs) have recently emerged as a new sub-class of MOFs which have demonstrated enormous potential for applications in sensing, imaging, optoelectronics and in solid-state lighting (SSL) technology. LMOFs could be game changers as lighting phosphors due to advantages such as high luminescence quantum yield, tunable excitation and emission which can be achieved by rational design and optimization of metal centers, linkers, and the guest molecules, facile fabrication into devices, and structural robustness. These clear advantageous features of LMOFs make them score over other contemporary materials, and enable them to be futuristic phosphor materials for WLED technology. In this feature article, we will provide an overview of the most recent developments of LMOF-based phosphor materials for SSL with a special focus on WLED technology. The emphasis will be centered around REE-free LMOFs, as the aim is to direct the attention of the readers towards a more viable and greener lighting technology. [ABSTRACT FROM AUTHOR]

The transition metal hydroxide NiFe LDH is a promising oxygen evolution reaction (OER) catalyst. Surface engineering, such as the introduction of oxygen vacancies into NiFe LDH, has been reported to further improve the OER performance; however, searching a facile approach remains an issue. In this work, we report a novel and efficient electrochemical reduction method for in situ introduction of oxygen vacancies into NiFe LDH laminates by applying a constant negative voltage. The results show that the reduced NiFe LDH (denoted as r-NiFe LDH) exhibits enhanced OER performance versus its counterpart NiFe due to the increase of oxygen vacancy density, the electrochemically active surface area, wetting ability, and the significant electron transfer rate. In 1 M KOH, the r-NiFe LDH shows a high current density of 110 mA cm−2 at 1.60 V (vs. RHE), which is 2.8 times the current density of NiFe LDH (40 mA cm−2), as well as the long-term stability of 100 h. This electroreduction method is also applicable to other LDH materials loaded by different current substrates or synthesized by various methods, demonstrating its universality for the enhancement of the OER activity of LDH electrocatalysts. [ABSTRACT FROM AUTHOR]

Biochar was modified by an acylation reaction using EDTA. Then, a novel biochar-based porous composite was successfully prepared using modified biochar as a base to remove Cu(II) in wastewater. In addition, functional groups, morphologies and the specific surface areas of EDTA-BIOC hydrogel were characterized by FT-IR, SEM, and BET, respectively. Various factors affecting the adsorption of Cu(II) on EDTA-BIOC hydrogel were investigated, such as pH, temperature, contact time, salinity, and initial concentration of Cu(II). Addition of EDTA greatly improved the adsorption capacity for Cu(II), and the maximum adsorption capacity of EDTA-BIOC hydrogel for Cu(II) was 93.9 mg g−1 at 318 K, which was higher than for biochar, gel-0 and EDTA-BIOC/SiO2 hydrogel. Cu(II) adsorption on EDTA-BIOC hydrogel was shown to fit well with the pseudo-second-order kinetic model and Langmuir isotherm. The adsorption mechanisms of Cu(II) by the hydrogel are systematically discussed, including physical adsorption, electrostatic attraction, cation exchange and complexation. Furthermore, EDTA-BIOC hydrogel could maintain a high adsorption capacity after five adsorption–desorption processes, which provided the possibility for recycling the EDTA-BIOC hydrogel multiple times. Finally, the adsorption capacity of EDTA-BIOC hydrogel for Cu(II) was studied in various water samples. The experimental results showed that EDTA-BIOC hydrogel exhibited great potential for treating different wastewaters containing Cu(II). [ABSTRACT FROM AUTHOR]

The rapid and sensitive surface-enhanced Raman scattering (SERS) detection of molecular biomarkers from real samples is still a challenge because the intrinsically trace analytes may have a low molecular affinity for metal surfaces. Herein, we develop a smart signal conversion and amplification strategy based on silver–gold–silica core-satellite structure nanoparticles (Ag@Au@SiO2 NPs) to sensitively detect low adsorptive vitamin E using SERS, which has been considered a biomarker of neuromuscular disorders when its abnormal content is measured in the serum of patients. Through the reducibility of vitamin E, Ag+ ions are rapidly reduced to Ag atoms, resulting in the epitaxial growth of Ag nanocrystals on gold nanoparticles forming satellite particle–particle gap-narrowed Ag@Au@SiO2 NPs. The generated strong plasmonic field dramatically enhances the Raman signal of the Raman reporter molecule 4-aminothiophenol (4-ATP) and the detected vitamin E molecules at an estimated level of 58.19 nmol L−1. The sensitivity of this operational SERS strategy provides tremendous prospects for the screening of neuromuscular disorders. [ABSTRACT FROM AUTHOR]

A novel Zn2+-based metal–organic framework (MOF) with the formula {[Zn(μ2-η1:η1-BBIP)(μ2-η1:η1:η1-OBA)]·3H2O}n, denoted as JXUST-7, has been successfully assembled using semi-rigid N-donor 3,5-bis(benzimidazol-1-yl)pyridine (BBIP) and flexible 4,4′-oxybisbenzoate (H2OBA). The adjacent Zn2+ ions are linked through an OBA2− ligand with a μ2-η1:η1:η1 bridging mode to form an infinite one-dimensional (1D) Zn2+–OBA2− chain. The neighbouring 1D chains are further connected by a BBIP ligand with a μ2-η1:η1 bridging mode to gain a two-dimensional (2D) sheet layer structure. Topological analysis indicates that the whole 2D structure of JXUST-7 could be simplified as a uninodal sql topology with a point symbol of {44·62}. Furthermore, the opposite parallel 2D layers are further packed by a face-to-face π–π interaction to generate a three-dimensional supramolecular structure. Luminescence experiments reveal that JXUST-7 could be considered as a multi-responsive MOF-based fluorescent probe toward Fe3+, Cr2O72− and acetylacetone (acac) via the fluorescence quenching (turn-off) effect. The detection limits for Fe3+, Cr2O72− and acac are 0.14, 1.33 and 6.53 ppm, respectively. The fluorescence quenching mechanism was analyzed in detail by powder X-ray diffraction, fluorescence lifetime measurement, X-ray photoelectron spectra, theoretical calculation and UV-Vis absorption spectra. More importantly, JXUST-7 could be cyclically utilized at least five times for detecting Fe3+, Cr2O72− and acac. [ABSTRACT FROM AUTHOR]

A Co–zeolite imidazole ester framework (ZIF-67) has excellent electrochemical performance for the oxygen reduction reaction (ORR), but the structural stability is still the key problem to be solved. PEDOT is a polymer of EDOT (3,4-ethylenedioxythiophene monomer), a π-conjugated conductive polymer with superior performance and wide application. It has a rigid and linear conformation, which is necessary to maintain the integrity of the material structure and prevent collapse. And this conformation is also conducive to charge transport and crystallization, resulting in good performance of high charge/discharge capacities, fast response time and high sensing ability. Herein through the pre-implantation of PEDOT nanowires, the structural collapse, anisotropic shrinkage and Co atom agglomeration of ZIF-67 in the pyrolysis process were inhibited, and S,N co-doping was realized at the same time. The XRD, SEM, TEM and XPS characterization studies prove that PEDOT nanowires successfully embedded in the ZIF-67 structure, and N and S are doped into the carbon framework of the catalyst. The synthesized catalyst has a regular hexahedral morphology, interconnected three-dimensional (3D) nanowire (NW) framework and graphitized carbon coated Co nanoparticles (Co/C@NS NWs), endowing it with excellent bifunctional catalytic performance toward oxygen. The initial potential was 0.91 V (vs. RHE) and the limiting current density was −4.8 mA cm−2 for the ORR. The potential required to reach 10 mA cm−2 is only 1.55 V (vs. RHE) and the Tafel slope for the oxygen evolution reaction (OER) is relatively low (100 mV dec−1). An open circuit voltage of 1.46 V for Zn–air battery cathodes catalyzed by Co/C@NS NWs at a discharge power density of 129.3 mWcm−2 is obtained, and the specific capacity at a discharge current density of 10 mA cm−1 is 800 mA h gZn−1. The voltages show no obvious change for a 35 h continuous discharge/charge cycle experiment. Therefore, this work provides a new inspiration for the design and development of high-performance non-noble metal carbon-based bifunctional oxygen electrocatalysts. [ABSTRACT FROM AUTHOR]

High-performance fluorescence sensors combining convenience, low cost and high sensitivity are prospective for water pollution and human health. Luminescent metal–organic frameworks (LMOFs) as sensors can meet these criteria for high efficient detection of toxic metal ions. Herein, a new LMOF LCU-109 has been fabricated by Sharpless in situ tetrazole synthesis system assisted by polycarboxylic O-donor ligand. It showed a 2D binodal (3,6)-connected kgd structure with multiple N and O dual-functional sites for detecting guest metal ions. As expected, LCU-109 can be highly sensitive and selectively detect trace amounts of Fe3+ and Cu2+ ions in an aqueous solution by the luminescence quenching mechanism. Notably, the detection limits (LODs) of Fe3+ and Cu2+ ions are 0.0043 and 0.0028 ppm, respectively, in water, which are significantly lower than the minimum standards stipulated for drinking water by the World Health Organization (WHO) (0.3/2.0 ppm) and U.S. Environmental Protection Agency (USEPA) (0.3/1.2 ppm). Moreover, LCU-109 also shows excellent luminescent sensing activities for Fe3+ and Cu2+ ions in simulated HEPES biological system and actual river water with low LODs of 0.034/0.019 ppm and 0.0756/0.107 ppm, respectively, which is also lower than the standard of WHO and USEPA. Moreover, convenient and real-time naked eye detection effects are provided by the exquisitely made LCU-109 fluorescent test papers. Importantly, combining density functional theory (DFT) calculations with a variety of experiments, the fluorescence quenching mechanism for energy competitive absorption and weak interaction is further revealed. [ABSTRACT FROM AUTHOR]

Seawater electrolysis provides a desirable pathway for large-scale production of green hydrogen without dependence on freshwater. However, its practical application is seriously hindered by low energy efficiency and insufficient durability because of the detrimental chlorine electro-oxidation and complex components of seawater. Herein, 2D MoN/Co2N hybrid nanosheets grown on 1D Cu nanowires and integrated on 3D Cu foam electrodes (Co/Mo–N–C/Cu) were fabricated for seawater splitting, which could enable the alkaline seawater electrolyzer assembled with these hierarchically structural electrodes to achieve a current density of 100 mA cm−2 at a low voltage of 1.70 V, along with good stability due to the synergistic effect among the MoN/Co2N hybrid nanosheets, unique 1D/2D/3D hierarchical structure, and the N-doped carbon protection layer. Theoretical calculations demonstrated that strong electron transfer occurred at heterogeneous interfaces, which could mediate the adsorption and desorption of intermediates, thus reducing the reaction energy barriers. [ABSTRACT FROM AUTHOR]

Volatile aldehydes cause great harm to human health and the living environment, and the detection of aldehydes has attracted much attention from chemists and material scientists. In recent years, as one of the most promising classes of functional materials, luminescent metal–organic frameworks (LMOFs) have bloomed as fluorescent sensors for the detection of aldehydes. Herein, the sensing properties of LMOF sensors toward formaldehyde, benzaldehyde, acetaldehyde and other aldehydes have been reviewed, and the sensing mechanism and applications are also illustrated. Additionally, the current status and its potential development prospects in this field are outlined. [ABSTRACT FROM AUTHOR]

Amide linkage of glycine–amino acid was synthesized by coupling of substituted 2-(aminomethyl)malononitrile as a C-terminal glycine unit and N-terminal amine using CsOAc and O2 in an aqueous solution. This is a coupling reagent-free and catalyst-free peptide synthesis via oxidative amide bond formation. Various tripeptides and tetrapeptides were synthesized efficiently and the sulfide moiety is inert even under an oxygen atmosphere. [ABSTRACT FROM AUTHOR]

The thinnest beryllium nanowires with high strength and uniformity are theoretically constructed of connected Be6 octahedron units. Based on this, Ca- and Mg-doped beryllium nanowires are successfully constructed and researched. They are unusual all-metal charge transfer salts Ca2+(Be6)n4−Mg2+ (n = 1–7), and they surprisingly display considerable second-order nonlinear optical (NLO) responses (β0e = 1.05 × 104–1.12 × 105 au). This is because the effect of doping Ca and Mg atoms brings great increase in β0e. In addition, more notably, the effect of the nanowire length on β0e revealed that the β0e value gradually and rapidly increases with the increase in the number of Be6 octahedron units (n). Thus, these doped beryllium nanowires are a new class of NLO nanowires. Fortunately, these NLO nanowires possess working wavebands in the infrared (IR, >2800 nm) and ultraviolet (UV, <200 nm) regions. Then, these doped beryllium NLO nanowires could also be used as new hot IR and UV NLO materials. Considering the dispersion effect, the frequency-dependent value of the electro-optical Pockels effect (EOPE) βe(−ω; ω, 0) at ω = 0.005 au is slightly larger than the corresponding value of β0e. Significantly, the effect of the nanowire length on βe(−ω; ω, 0) is also displayed. Obviously, a new design strategy of enhancing NLO responses by increasing n was obtained. Noticeably, the nanowires display Janus electronic properties of both stronger electron-donating and electron-withdrawing behaviors. This work predicts that novel metal nanowires may be applied in new hot IR and UV NLO materials as well as molecular electronic devices. [ABSTRACT FROM AUTHOR]

Recently, low-dimensional organic–inorganic hybrid metal halides have attracted considerable attention in solid-state optical application fields, especially in white-light emitting diodes (WLEDs) owing to intrinsic broadband luminescence performances. Herein, by selecting different types of organic cations as a structural decoration strategy, we designed a series of new 1D hybrid halides of A2Pb3Br10 (A = NPM, DMPDA, TMEN) based on same [Pb3Br10]4− chains composed of edge-shared [Pb3Br12]6− trimers. The low-dimensional crystal lattice results in the formation of self-trapped excitons, which leads to broadband light emissions covering the entire visible region for all A2Pb3Br10 homologues. Specifically, compound 1 exhibits yellowish-white light emission (0.34, 0.45) with a photoluminescence quantum efficiency of 2.51%. Both compounds 2 and 3 show bluish-white light emissions centered at 438 nm and 440 nm, respectively, with high color rendering index (CRI) of 96, which belongs to one of the highest values to date. The intrinsic broadband white light emissions enable them as promising candidates for single-component white-light emitting materials. [ABSTRACT FROM AUTHOR]

A dual functional nanoprobe Pd–Q+@PDMS was proposed to simultaneously monitor Cl− and O2, leading to the determination of an average Cl− concentration of 85.7 ± 5.5 mM in lysosomes of HeLa cells. Mimicking ischemic conditions, the cells exhibited a luminescence change corresponding to a decreasing subcellular Cl− concentration. [ABSTRACT FROM AUTHOR]

For the challenge of stabilizing a fullerene-like borospherene, a perfect fullerene-like borospherene B20 with Ih symmetry is stabilized theoretically for the first time by selected 12 η5 (pentahapto)-Mg atoms capped on the 12 B5 pentagons, forming an exohedral metalloborospherene Ih Mg12&B20 molecule. Owing to the pull–push electron transfer relay, the molecule is converted to a spherical electride molecule (Mg2+)12&B2018− + 6e− with multiexcess electrons and high-valent B2018− polyanion with a full-shell electronic configuration, performing the stabilization of the fullerene-like B20 cage. Furthermore, we embed the metal M atom in the B20 cage, forming new endohedral electride molecules (Mg2+)12&(Mn+@B2018−) + (6 + n)e− (M = Li, n = 1 and Mg, n = 2). The embedded atom M increases the excess electron number. Notably, these electride molecules possess two different types of superatomic characteristics, exhibiting the behavior of an electron reservoir. Moreover, a compound (Mg12&B20)2O is designed and obtained, so Mg12&B20 might serve as a nano-building block. In addition, the Mg12&B20 and Mg12&(Mg@B20) electride molecules are efficient external electric field-manipulated nonlinear optical (NLO) switches with high sensitivity and reversibility. The embedding metal atom in the B20 cage can also serve as a new strategy to manipulate NLO switching. [ABSTRACT FROM AUTHOR]

Pt/C and SO42−/ZrO2 were mechanically mixed as the catalysts for p-aminophenol synthesis by catalytic transfer hydrogenation of nitrobenzene in water with formic acid as the hydrogen source. The effect of Pt loading and the solid acid on the reaction was investigated. PAP selectivity reached a maximum at a loading of 1 wt%. The characterization results revealed the presence of three valence states of Pt. Pt0 was beneficial for the nitrobenzene hydrogenation, while higher valence Pt contributed to the formic acid decomposition. The catalytic performance of different solid acid catalysts, including HZSM-5, Hβ, SO42−/ZrO2 and SO42−/TiO2, was compared. It was found that Lewis acid sites with strong acid strength were favorable for p-aminophenol formation, and SO42−/ZrO2 showed higher catalytic activity for the reaction. Using Pt/C + SO42−/ZrO2 as the catalyst, the reaction conditions were optimized. Under the optimal reaction conditions, the nitrobenzene conversion and the p-aminophenol selectivity were 80.0% and 47.6%, respectively. The reaction mechanism was also proposed based on the main by-products of the reaction. [ABSTRACT FROM AUTHOR]

Herein, we developed an amplified AND logic platform (AALP) on a cell membrane, which integrated two DNA aptamers for cell recognition and localized catalytic hairpin assembly (LCHA) for signal amplification. The AALP could perform "AND" logic computing via a double-checked strategy of two biomarkers on similar cell surfaces and precisely label the target cells with an amplified fluorescence signal. [ABSTRACT FROM AUTHOR]

A set of transition-metal-free NaI/TBHP-mediated sulfonylation cyclization reactions of methylthiolated alkynones with sulfonyl hydrazides was developed, by which various 3-sulfonylated thioflavones were prepared under mild reaction conditions. The features of this procedure included metal-free reaction conditions, ease of reagent handling, short reaction times, and a broad functional group tolerance. [ABSTRACT FROM AUTHOR]

Inspired by the natural enzyme cascade reaction, an artificial DNAzyme cascade system is developed for the amplified detection of intracellular miR-141. The results showed that the method enormously enhanced the readout of the fluorescence signal and achieved a femtomolar detection limit. [ABSTRACT FROM AUTHOR]

A novel, facile and universal N2 plasma approach to form single atom metal sites (Pt, Pd, Ag, Cu, and Co) is proposed. Fast nucleation and slow growth of metal ions under low temperature plasma are the premise to form single atoms. These isolated metal atoms are subsequently trapped by in situ doped nitrogen. We provide a new route to expand the toolbox of single-atoms preparation. [ABSTRACT FROM AUTHOR]

Chiral organic compounds are excellent second-order nonlinear optical (NLO) materials due to their intrinsic asymmetric structures combined with the advantages of organic compounds. Here, based on linear [3]spirobifluorenylene, seven compounds are designed by introduction of donor/acceptor units and their combinations at different substituent positions. The ground state electronic structures, electronic transition, and second-order NLO properties of these compounds are fully investigated by DFT/TDDFT theory. The simulated electron absorption wavelengths and CD spectrum are in good agreement with the experimental ones, enabling us to fully specify the electronic transition properties and absolute configuration. It is found that the combination introduction of donor units and acceptor units is the most effective way to not only tune the energy gap and electron transition properties but also enhance the NLO response. For instance, the second-order NLO value of compound 8 is (109.76 × 10−30 esu) which is about 26 times larger than that of the highly π-delocalized phenyliminomethylferrocene complex, which is attributed to obvious charge transfer. In view of their large NLO response and intrinsic asymmetric structures, the studied compounds have the possibility to be excellent second-order NLO materials. [ABSTRACT FROM AUTHOR]

A series of dinuclear platinum(II) alkynyl complexes [Pt2L2(C≡CC6H4R-4)4] (R = H 1, CH32, But3) and unusual tetranuclear Pt(II)–Ag(I) clusters [Pt2Ag2L(C≡CC6H4R-4)6] (R = H, 4; CH3, 5; But, 6), together with novel polymer crystals [Pt2Ag2L(C≡CC6H5)6]∞ ([4]∞), were synthesized by a self-assembly reaction between [NBu4]2[Pt(C≡CC6H4-R-4)4] and [Ag6L6]6+ (L = 4-(3,5-(diphenylphosphine)phenyl)pyridine). These complexes were characterized by using a range of spectroscopic techniques and complexes 1, 3, 5, and [4]∞ were analysed by X-ray crystallography. Each platinum atom of the Pt(II)–Ag(I) clusters shows an unusual asymmetric distorted square planar geometry with three alkynyl groups and one bridging L phosphorus atom. Dinuclear complexes 1–3 demonstrate solid-state weak blue luminescence, while tetranuclear Pt(II)–Ag(I) clusters 4–6 show intense blue-green or yellow-green emission. Furthermore, the crystalline samples of polymer [4]∞ display bright yellow emission (518 nm) that is significantly red-shifted as compared to monomer crystal 4. [ABSTRACT FROM AUTHOR]

An electrochemical dehydrogenative [2 + 2 + 1] annulation used for the synthesis of imidazoles has been developed under undivided electrolytic conditions. In an undivided cell, aryl ketones and amines can smoothly participate in this transformation to furnish a variety of substituted imidazoles. The reaction avoids the use of both transition-metal catalysts and peroxide reagents, which makes it more sustainable and renewable. [ABSTRACT FROM AUTHOR]

In 2015, we proposed FRET nanoflares for intracellular molecular (RNA, H+, and K+) detection. To improve detection accuracy and achieve on-demand sensing, herein, we developed photocaged FRET nanoflares for spatiotemporal microRNA imaging in living cells. In other words, the probes will not work until they are exposed to UV light. [ABSTRACT FROM AUTHOR]

A supramolecular assembly was constructed by the nonconvalent interaction of pillar[5]arene (WP5) with a pyridinium modified tetraphenylethene (Py-TPE) derivative, in which Py-TPE/WP5 acted as a donor, and sulforhodamine 101 and sulfonated aluminum phthalocyanine acted as acceptors to realize a highly efficient light-harvesting system with two-step sequential energy transfer. [ABSTRACT FROM AUTHOR]

Although carbon nanomaterials show good potential as efficient electrocatalysts for oxygen reduction reaction (ORR), their inferior long-term stability due to their high surface energy resulting in compact restacking limits their practical performance. To overcome this issue, here, we design and construct an anti-agglomerating single-walled carbon nanotube (SWNT) catalyst by using poly-3,4-ethylenedioxythiophene (PEDOT) as an upholder. Physical characteristic results indicate that PEDOT effectively fills in the interweaved zone or adheres to the SWNT surface. Furthermore, S atoms can be doped into the lattice and produce more defects. Electrochemical tests show that SWNTs@PEDOT exhibits similar catalytic activities towards ORR to SWNTs, and both of them can realize a quasi-4e ORR pathway. Within a 32 000 s long-term test, the cathodic current of the SWNTs toward ORR gradually decays to 58% of the initial value; in contrast, SWNTs@PEDOT shows excellent stability with several stages of rise, fall, rise to 105% of the initial current. The excellent stability is due to the stable skeleton caused by PEDOT preventing agglomeration of SWNTs. The equilibrium of swelling and shrinkage of PEDOT even lead to an increase and favorable stability of the current. This suggests a practical method to overcome the weakness of agglomeration, thus enhancing the long-term stability for nano-carbon catalysts. [ABSTRACT FROM AUTHOR]

To study the influence of twinned crystals on the performance of TKX-50, normal TKX-50 (N-TKX-50) and twinned TKX-50 (T-TKX-50) supercells are constructed, and ReaxFF-lg reactive molecular dynamics simulations are performed to study the thermal decomposition and oxidation of N-TKX-50 and T-TKX-50 at 1000, 2000 and 3000 K. The mechanism of thermal decomposition and oxidation of N-TKX-50 and T-TKX-50 are analyzed in terms of potential energy evolution, primary reaction paths, and the intermediate and final products. We find that T-TKX-50 possesses higher decomposition and consumption rate than N-TKX-50 at the same temperature conditions, while the decomposition and the oxidation end-products of N-TKX-50 and T-TKX-50 are the same. These results confirm that the T-TKX-50 crystal is unfavorable for the thermal stability of TKX-50. We believe that this work can provide some guidance for investigating the decomposition and oxidation of other materials. [ABSTRACT FROM AUTHOR]

The first coordination disk-type nano-Saturn complexes, [Cu10(Mim)10]⊃C60 and [Cu10(Mim)10]⊃C70 (Mim = 2-methylimidazolate), were assembled under one-pot solvothermal conditions. The highest number of 30 C–H⋯π interactions between the [Cu10(Mim)10] disk and the C60/C70 surfaces drives the formation of the nano-Saturns. The calculated interaction energy is much larger than that of most of the reported disk-type nano-Saturns. Different photoinduced charge/energy transfer mechanisms are present for both nano-Saturn systems to quench the intrinsic luminescence of the [Cu10(Mim)10] disk. [ABSTRACT FROM AUTHOR]

Inspired by the natural enzyme cascade reaction, a multiple DNAzyme cascade platform is engineered to imitate the intracellular process of signal transduction and signal amplification. In this design, when particular stimuli appear, an activated upstream DNAzyme will cleave a well-designed intermediary S1, releasing a downstream DNAzyme that can cleave the reporter substrate S2 to output signals. Thus, the signal is passed from the upstream DNAzyme to the downstream DNAzyme through a well-designed intermediary, accomplishing signal transduction and signal amplification. According to the experimental results, the DNAzyme cascades are capable of improving sensitivity for bioassays compared with that for single DNAzyme-based biocatalysis, which holds promise for potential applications, such as biomolecular computing, logic circuits and precision medicine. [ABSTRACT FROM AUTHOR]

Control of magnetic performances of molecular magnets is essential but few efforts have been documented. A green and efficient sonication assisted synthesis of a new heterometallic diruthenium(II , III) carbonate, Na[Ni(H2O)4Ru2(CO3)4]·3H2O (1), was carried out by self-assembling in aqueous solution. Compound 1 exhibits spin-glass behavior below ∼5.0 K, and a systematic investigation of the ultrasonic irradiation influence on the powder samples reveals that their coercivity increases from 50 Oe to 743 Oe with the control of ultrasonic power under appropriate conditions. [ABSTRACT FROM AUTHOR]

Ultra-high-density rhenium diselenide (ReSe2) nanoflakes were synthesized on a porous carbon cloth (PCC) by chemical vapor deposition (CVD). Besides the two-dimensional/three-dimensional (2D/3D) construction with more active catalytic sites, the small size effect together with the interfacial C–Se bonding facilitated the electron transport between ReSe2 and PCC. Hence, the heat-treated ReSe2@PCC with enhanced charge transport is by far the best performance electrode for the hydrogen evolution reaction (HER) among the state-of-the-art ReX2-based electrodes. [ABSTRACT FROM AUTHOR]

Hg2+ is highly toxic and hazardous and widely found in polluted water. To remove mercury ions from wastewater, there is an urgent need to investigate and develop new adsorbents. Herein, we synthesized three novel thioether-based metal–organic frameworks (MOFs) through a facile diffusion method or a solvothermal strategy, i.e. [(ZnCl2)3(L1)2·χ(solvent)]n (1), [(Cu2I3O2)4(CH4N0.5)4(L1)4(DMA)4·3(H2O)·χ(solvent)]n (2) and [(CuBr2)2(L2)2 CH3CN·χ(solvent)]n (3), where L1 = 1,3,5-tris((pyridin-4-ylthio)methyl)benzene and L2 = 2,4,6-trimethoxy-1,3,5-tris((pyridin-4-ylthio)methyl)benzene. The obtained thioether-based MOFs were characterized by single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis. Further studies revealed that they could remove Hg2+ from water. They have high adsorptivity (up to 362 mg g−1) and are highly efficient in removing Hg2+ (up to 95%). Besides, these MOFs can be recycled and can selectively remove Hg2+ from water in the presence of other metal ions. Consequently, these MOFs are highly promising candidates for the selective absorption and removal of mercury ions from water. [ABSTRACT FROM AUTHOR]

Pr3+:CaTiO3, a robust persistent luminescent material, was coupled with chiral molecules and Ag nanoparticles (NPs) to construct a Pr3+:CaTiO3@Ag@ L -cysteine ternary material that can realize rapid enantiomer selective sensing of L - and D -arginine by making use of the chiral induced spin selectivity (CISS) effect. In addition, long-lifetime photoelectrons excited in the Pr3+:CaTiO3 matrix were effectively transported through a Ag NP "bridge" into the L -cysteine chiral monolayer, due to cooperation between each component in the ternary material. [ABSTRACT FROM AUTHOR]

To understand the possible mechanisms of hexavalent chromium (Cr(VI)) adsorption on the surface of modified layered double hydroxides (LDHs), we synthesized ethylenediaminetetraacetic acid intercalated MgAl-LDH (LDH-EDTA) and its magnetic product (Mag-LDH-EDTA), and evaluated their adsorption performance for Cr(VI) by batch equilibrium experiments. The characterization analysis proved that the EDTA was intercalated into MgAl-LDH and the adsorbents had an ordered structure and abundant functional groups. The adsorption mechanisms of Cr(VI) by LDH-EDTA and Mag-LDH-EDTA could be attributed as electrostatic attraction, surface complexation, anion exchange, and reduction reaction speculating from the detailed X-ray diffraction patterns (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis. The removal ratio remained above 96% and 79% for 50 mg L−1 Cr(VI) using 0.03 g LDH-EDTA and Mag-LDH-EDTA, respectively. The adsorption process was less influenced by the pH value of the aqueous solution. The pseudo-second-order model and the Langmuir equation well fitted to the adsorption kinetic and isotherm data. Thus, the EDTA intercalated LDH materials had potential applications for Cr(VI) removal in real wastewater treatment. [ABSTRACT FROM AUTHOR]

A luminescent edge-interlocked heteroleptic metallocage based on Cu3(pyrazolate)3 was prepared through a ligand replacement reaction from a homoleptic metallocage and a new ligand. Its structure was confirmed by XRD and MALDI-TOF mass spectrometry. Theoretical calculations revealed the new ligand was evidently responsible for the bathochromic shift of the optimal excitation. This work provides a heteroleptic strategy to regulate the interlocking fashion and photophysical mechanism of metallocages based on Cu3(pyrazolate)3. [ABSTRACT FROM AUTHOR]