CuCo2O4/CuO Heterostructure with Oxygen Vacancies Induced by Plasma for Electrocatalytic Nitrate Reduction to Ammonia.

Electrochemical nitrate reduction (NO3RR) to ammonia production is regarded as one of the potential alternatives for replacing the Haber-Bosch technology for realizing artificial ammonia synthesis. In this study, a CuCo2O4/CuO-Ar heterostructure in the shape of dandelion nanospheres formed by nanoarrays has been successfully constructed, demonstrating excellent NO3RR performance. Experimental results indicate that Ar plasma etching of CuCo2O4/CuO-Ar significantly increases the content of oxygen vacancies compared to the sample of CuCo2O4/CuO-Air etched by air plasma, resulting in improved NO3RR performance. Density functional theory calculations further confirm that the existence of more oxygen vacancies effectively decreases the energy barrier of nitrate adsorption, which is due to the generation of more oxygen vacancies facilitating nitrate adsorption and weakening the N-O bonds of nitrate after plasma treatment. As a result, CuCo2O4/CuO-Ar exhibits a high NH3 yield of 0.55 mmol h-1 cm-2 and a Faraday efficiency of 95.07% at the optimal potential of -0.9 V (vs RHE) in a neutral medium. Importantly, CuCo2O4/CuO-Ar also showcases excellent electrocatalytic stability. This study presents new views on the design and structure regulation of NO3RR electrocatalysts and their potential applications in the future.

A One-Step Self-Flowering Method toward Programmable Ultrathin Porous Carbon-Based Materials for Microwave Absorption and Hydrogen Evolution.

Ultrathin 2D porous carbon-based materials offer numerous fascinating electrical, catalytic, and mechanical properties, which hold great promise in various applications. However, it remains a formidable challenge to fabricate these materials with tunable morphology and composition by a simple synthesis strategy. Here, a facile one-step self-flowering method without purification and harsh conditions is reported for large-scale fabrication of high-quality ultrathin (≈1.5 nm) N-doped porous carbon nanosheets (NPC) and their composites. It is demonstrated that the layered tannic/oxamide (TA/oxamide) hybrid is spontaneously blown, exfoliated, bloomed, in situ pore-formed, and aromatized during pyrolysis to form flower-like aggregated NPC. This universal one-step self-flowering system is compatible with various precursors to construct multiscale NPC-based composites (Ru@NPC, ZnO@NPC, MoS2 @NPC, Co@NPC, rGO@NPC, etc.). Notably, the programmable architecture enables NPC-based materials with excellent multifunctional performances, such as microwave absorption and hydrogen evolution. This work provides a facile, universal, scalable, and eco-friendly avenue to fabricate functional ultrathin porous carbon-based materials with programmability.

Cu2+1O/Ag Heterostructure for Boosting the Electrocatalytic Nitrate Reduction to Ammonia Performance.

Electrocatalytic nitrate reduction reaction (ENO3RR) is an alternative, sustainable, and environmentally friendly value-added NH3 synthesis method under ambient conditions relative to the traditional Haber-Bosch process; however, its low NH3 yield, low Faradaic efficiency (FE), low selectivity, and low conversion rate severely restrict the development. In this work, a Cu2+1O/Ag-CC heterostructured electrocatalyst was successfully fabricated by constructing a heterogeneous interface between Cu2+1O and Ag for selective electrochemical nitrate-to-ammonia conversion. The construction of the heterogeneous interface effectively promotes the synergistic effect of the catalytically active components Cu2+1O and Ag, which enhances the material conductivity, accelerates the interfacial electron transfer, and exposes more active sites, thus improving the performance of ENO3RR. Such Cu2+1O/Ag-CC manifests a high NH3 yield of 2.2 mg h-1 cm-2 and a notable ammonia FE of 85.03% at the optimal applied potential of -0.74 V vs RHE in a relatively low concentration of 0.01 M NO3--containing 0.1 M KOH. Moreover, it shows excellent electrochemical stability during the cycle tests. Our study not only provides an efficient catalyst for ammonia electro-synthesis from ENO3RR but also an effective strategy for the construction of ENO3RR electrocatalysts for electrocatalytic applications.

Fe1-xNix(PO3)2/Ni2P Heterostructure for Boosting Alkaline Oxygen Evolution Reaction in Fresh Water and Real Seawater at High Current Density.

Oxygen evolution reaction (OER) is a limiting reaction for highly efficient water electrolysis. Thus, the development of cost-effective and highly efficient OER catalysts is the key to large-scale water electrolysis for hydrogen production. Herein, by using an interfacial engineering strategy, a unique nanoflower-like Fe1-xNix(PO3)2/Ni2P/NF heterostructure with abundant heterogeneous interfaces is successfully fabricated. The catalyst exhibits excellent OER catalytic activity in alkaline fresh water and alkaline natural seawater at high current densities, which only, respectively, requires overpotentials of 318 and 367 mV to drive 1000 mA cm-2 in fresh water and natural seawater both containing 1 M KOH. Furthermore, Fe1-xNix(PO3)2/Ni2P/NF demonstrates excellent durability, which can basically remain stable for 80 h during the electrocatalytic OER processes, respectively, in alkaline fresh water and natural seawater. This work provides a new construction strategy for designing highly efficient electrocatalysts for OER at high current densities both in alkaline fresh water and in natural seawater.

Multicomponent TiO2/Ag/Cu7S4@Se Heterostructures Constructed by an Interface Engineering Strategy for Promoting the Electrocatalytic Nitrogen Reduction Reaction Performance.

The electrocatalytic nitrogen reduction reaction (ECNRR) is a sustainable and environmentally friendly method for NH3 synthesis under environmental conditions relative to the Haber-Bosch process; however, its low selectivity (Faradaic efficiency (FE)) and low NH3 yield impede the progress. Herein, benefiting from the application of the interface engineering strategy, a multicomponent TiO2/Ag/Cu7S4@Se-CC heterogeneous electrocatalyst with a unique structure was successfully fabricated, generating a unique sandwich structure by using a Ag layer as an electric bridge intercalated between TiO2 and Cu7S4, in which the optimized catalyst can accelerate the electron transfer efficiency. Moreover, through the electronic structure adjustment, an electron-deficient region was constructed, which can inhibit the H2 adsorption but enhance the N2 adsorption, thereby improving the selectivity and the catalytic activity. Significantly, the FE and NH3 yield of TiO2/Ag/Cu7S4@Se-CC reached 51.05 ± 0.16% and 39.16 ± 2.31 µg h-1 cm-2, in which the FE is among the highest non-precious metal-based NRR electrocatalysts in alkaline electrolytes reported. This study provides insight into the rational design and construction of NRR electrocatalysts for electrocatalytic applications.

Effects of Metal Blending in Random Bimetallic Single-Chain Magnets: Synergetic, Antagonistic, or Innocent.

A family of isomorphous three-dimensional metal-organic frameworks based on bimetallic (FeCo, FeNi, and CoNi) chains with random metal sites have been prepared and magnetically characterized. The solid-solution-type bimetallic materials inherit intrachain ferromagnetic interactions and single-chain-magnet (SCM) behaviors from the homometallic parent materials. Interestingly, different composition dependence of magnetic behaviors has been found. The FeII1-x NiIIx series (0≤x≤1) show an innocent composition dependence, where the blocking temperature of slow relaxation decreases monotonically as FeII is replaced by less anisotropic NiII . The FeII1-x CoIIx series show an unexpected antagonistic blending effect on slow relaxation: blending FeII and CoII tends to depress the spin dynamics, and the bimetallic materials with intermediate composition show significantly lower blocking temperature than both FeII and CoII materials. This is quite the opposite of what happens in the Co1-x Nix series, where CoII and NiII seem to have a synergetic effect so that slow relaxation in bimetallic systems can be promoted to higher temperature than both CoII and NiII materials.

An overview of potential molecular mechanisms involved in VSMC phenotypic modulation.

The fully differentiated medial vascular smooth muscle cells (VSMCs) of mature vessels keep quiescent and contractile. However, VSMC can exhibit the plasticity in phenotype switching from a differentiated and contractile phenotype to a dedifferentiated state in response to alterations in local environmental cues, which is called phenotypic modulation or switching. Distinguishing from its differentiated state expressing more smooth muscle (SM)-specific/selective proteins, the phenotypic modulation in VSMC is characterized by an increased rate of proliferation, migration, synthesis of extracellular matrix proteins and decreased expression of SM contractile proteins. Although it has been well demonstrated that phenotypic modulation of VSMC contributes to the occurrence and progression of many proliferative vascular diseases, little is known about the details of the molecular mechanisms of VSMC phenotypic modulation. Growing evidence suggests that variety of molecules including microRNAs, cytokines and biochemical factors, membrane receptors, ion channels, cytoskeleton and extracellular matrix play important roles in controlling VSMC phenotype. The focus of the present review is to provide an overview of potential molecular mechanisms involved in VSMC phenotypic modulation in recent years. To clarify VSMC differentiation and phenotypic modulation mechanisms will contribute to producing cell-based therapeutic interventions for aberrant VSMC differentiation-related diseases.

Association between serum uric acid levels and cerebral white matter lesions in Chinese individuals.

PURPOSE/AIM OF THE STUDY: We aimed to evaluate the association between serum uric acid (SUA) levels and cerebral white matter lesions (WMLs) in Chinese individuals. MATERIAL AND METHODS: We prospectively identified patients aged 50 years and older in neurology department from July 2014 to March 2015. Both periventricular WMLs (P-WMLs) and deep WMLs (D-WMLs) were identified on magnetic resonance imanging (MRI) scans and the severity was graded using the Fazekas method. Multivariate logistic regression analyses were performed to examine the association between SUA and WMLs. RESULTS: A total of 480 eligible participants were enrolled in this study. SUA level in severe group was much higher than that in mild group (for P-WMLs: 320.21 ± 79.97 vs. 286.29 ± 70.18, p = 0.000; for D-WMLs: 314.71 ± 74.74 vs. 290.07 ± 74.04, p = 0.031). Subgroup analyses showed that higher SUA level was associated with higher severity of P-WMLs in women, but not in male patients. Multivariate logistic regression analyses showed that SUA was still associated with increased risk of higher severity of P-WMLs (OR = 1.003, 95% = 1.000-1.006), but not D-WMLs. CONCLUSION: Elevated SUA level was independently associated with greater odds of higher severity of P-WMLs, particularly in women.

cis-Tri-aqua-[1,1'-(propane-1,3-di-yl)bis-(pyridin-1-ium-4-carboxyl-ato)-κO]bis-(thio-cyanato-κN)manganese(II) dihydrate.

In the title compound, [Mn(NCS)2(C15H14N2O4)(H2O)3]·2H2O, the metal ion is octa-hedrally coordinated by three water mol-ecules, one carboxyl-ate O atom from a 1,1'-(propane-1,3-di-yl)bis-(pyridinium-4-carboxyl-ate) ligand and two N atoms from two thio-cyanate anions in cis positions, forming a mononuclear complex mol-ecule. In the crystal, mol-ecules are connected into a three-dimensional architecture through O-H⋯O hydrogen bonds involving water mol-ecules and carboxyl-ate groups.

Pd/NbOPO4 multifunctional catalyst for the direct production of liquid alkanes from aldol adducts of furans.

Great efforts have been made to convert renewable biomass into transportation fuels. Herein, we report the novel properties of NbO(x)-based catalysts in the hydrodeoxygenation of furan-derived adducts to liquid alkanes. Excellent activity and stability were observed with almost no decrease in octane yield (>90% throughout) in a 256 h time-on-stream test. Experimental and theoretical studies showed that NbO(x) species play the key role in C-O bond cleavage. As a multifunctional catalyst, Pd/NbOPO4 plays three roles in the conversion of aldol adducts into alkanes: 1) The noble metal (in this case Pd) is the active center for hydrogenation; 2) NbO(x) species help to cleave the C-O bond, especially of the tetrahydrofuran ring; and 3) a niobium-based solid acid catalyzes the dehydration, thus enabling the quantitative conversion of furan-derived adducts into alkanes under mild conditions.

Ce-doped copper oxide and copper vanadate Cu3VO4 hybrid for boosting nitrate electroreduction to ammonia.

The electrocatalytic nitrate reduction to ammonia reaction (ENO3RR) holds great potential as a cost-effective method for synthesizing ammonia. This work designed a cerium (Ce) doped Cu2+1O/Cu3VO4 catalyst. The coupling of vanadium-based oxides with Cu2+1O effectively adjusts the catalyst's electronic structure, addressing the inherent issues of limited activity and low conductivity in typical copper-based oxides; moreover, Ce doping generates oxygen vacancies (Ov), providing more active sites and thereby enhancing the ENO3RR performance. The catalyst exhibits superior NH3Faradaic efficiency (93.7 %) with a NH3 yield of 18.905 mg h-1 cm-2at -0.5 V vs. RHE under alkaline conditions. This study provides guidance for the design of highly efficient catalysts for ENO3RR.

Controllable proton-reservoir ordered gel towards reversible switching and reliable electromagnetic interference shielding.

Smart and dynamic electromagnetic interference (EMI) shielding materials possess a remarkable capacity to modify their EMI shielding abilities, rendering them invaluable in various civil and military applications. However, the present response mechanism of switch-type EMI shielding materials is slightly restricted, as it primarily depends on continuous pressure induction, thereby resulting in concerns regarding their durability and reliability. Herein, for the first time, we demonstrate a novel method for achieving solvent-responsive, reversible switching, and robust EMI shielding capabilities using a controlled proton-reservoir ordered gel. The gel contains polyaniline (PANI) and sodium alginate (SA). Initially, SA acts as a proton reservoir for PANI in an aqueous system, enhancing the doping level of PANI and improving its electrical conductivity. Additionally, PANI and SA chains respond to diverse polar solvents, such as water, acetonitrile, ethanol, n-hexane, and air, inducing distinct conformations that affect the degree of PANI conjugation and electron migration along the chains. This process is reversible and non-destructive to the polymer chain, ensuring the effective and uncompromised performance of the EMI shielding switch. We can achieve precise and reversible tuning (on/off) of EMI shielding with different effectiveness levels by manipulating the solvents within the framework. This work opens a new solvent-stimuli avenue for the development of EMI shielding materials with reliable and intelligent on/off switching capabilities.

A photoluminescent hydrogen-bonded biomass aerogel for sustainable radiative cooling.

Passive radiant cooling is a potentially sustainable thermal management strategy amid escalating global climate change. However, petrochemical-derived cooling materials often face efficiency challenges owing to the absorption of sunlight. We present an intrinsic photoluminescent biomass aerogel, which has a visible light reflectance exceeding 100%, that yields a large cooling effect. We discovered that DNA and gelatin aggregation into an ordered layered aerogel achieves a solar-weighted reflectance of 104.0% in visible light regions through fluorescence and phosphorescence. The cooling effect can reduce ambient temperatures by 16.0°C under high solar irradiance. In addition, the aerogel, efficiently produced at scale through water-welding, displays high reparability, recyclability, and biodegradability, completing an environmentally conscious life cycle. This biomass photoluminescence material is another tool for designing next-generation sustainable cooling materials.

Manganese(II), iron(II), and mixed-metal metal-organic frameworks based on chains with mixed carboxylate and azide bridges: magnetic coupling and slow relaxation.

Mn(II) and Fe(II) compounds derived from azide and the zwitterionic 1-carboxylatomethylpyridinium-4-carboxylate ligand are isomorphous three-dimensional metal-organic frameworks (MOFs) with the sra net, in which the metal ions are connected into anionic chains by mixed (µ-1,1-azide)bis(µ-carboxylate) triple bridges and the chains are cross-linked by the cationic backbones of the zwitterionic ligands. The Mn(II) MOFs display typical one-dimensional antiferromagnetic behavior. In contrast, with one more d electron per metal center, the Fe(II) counterpart shows intrachain ferromagnetic interactions and slow relaxation of magnetization attributable to the single-chain components. The activation energies for magnetization reversal in the infinite- and finite-chain regimes are Δτ1 = 154 K and Δτ2 = 124 K, respectively. Taking advantage of the isomorphism between the Mn(II) and Fe(II) MOFs, we have prepared a series of mixed-metal Mn(II)(1-x)Fe(II)(x) MOFs with x = 0.41, 0.63, and 0.76, which intrinsically feature random isotropic/anisotropic sites and competing antiferromagnetic-ferromagnetic interactions. The materials show a gradual antiferromagnetic-to-ferromagnetic evolution in overall behaviors as the Fe(II) content increases, and the Fe-rich materials show complex relaxation processes that may arise for mixed SCM and spin-glass mechanisms. A general trend is that the activation energy and the blocking temperature increase with the Fe(II) content, emphasizing the importance of anisotropy for slow relaxation of magnetization.

[Protective effects of crude polysaccharides from Chroogomphus rutilus on SH-SY5Y cells impaired by MPP(+)].

The aim of the present study was to investigate the protective effects of crude polysaccharides from Chroogomphus rutilus on dopaminergic neurons impaired by MPP(+). SH-SY5Y cells were pretreated with crude polysaccharides (200, 400 and 800 µg/mL), and then MPP(+) was added to cell medium. After 48 h of incubation, MTT method was used to detect the survival rate of SH-SY5Y cells damaged by MPP(+). Annexin V-FITC staining and flow cytometry were used to detect apoptotic rate. The results showed that pretreating SH-SY5Y cells with crude polysaccharides (400 and 800 µg/mL) increased the survival rates, and reduced the apoptotic rates of SH-SY5Y cells. To rule out the possibility that crude polysaccharides may decrease actual concentration of MPP(+) by direct binding, we washed off crude polysaccharides before MPP(+) addition. Under this experimental condition, MTT results showed the survival rates of the SH-SY5Y cells were still significantly increased by 800 µg/mL crude polysaccharides pretreatment. These results suggest a protective effect of polysaccharides on the SH-SY5Y cells. Most of this protection is contributed by direct action of polysaccharides on the cells, not by binding with MPP(+). It is indicated that the crude polysaccharides from Chroogomphus rutilus can be developed as a potential drug for Parkinson's disease prevention and treatment in the future.

Cu/NiO nanorods for efficiently promoting the electrochemical nitrate reduction to ammonia.

The electrochemical nitrate reduction reaction (ENO3RR) is a green ammonia synthesis method under ambient conditions relative to the traditional Haber-Bosch technology, which does not require high-temperature or high-pressure conditions and can convert nitrate pollutants in the environment into value-added NH3, thus achieving a dual purpose. However, more electrocatalysts with a remarkable performance towards high-efficiency ENO3RR need to be developed. In this work, a Cu/NiO-NF composite electrocatalyst with a nanorod structure on nickel foam was successfully fabricated, which contains heterogeneous interfaces between Cu and NiO toward selective electrocatalytic nitrate reduction for ammonia synthesis. The steric nanorod morphology of the catalyst can significantly increase the surface area, expose more active sites, and improve the reaction activity. Moreover, the construction of the composite and the interface effectively boosts the synergistic effect of the active species Cu and NiO, which can regulate the electronic structure of the catalyst, expose more active sites, enhance the conductivity of the material, and accelerate the interfacial electron transfer, thereby further promoting the ENO3RR performance. This Cu/NiO-NF composite exhibits a high NH3 yield of 0.6 mmol h-1 cm-2 and up to 97.81% faradaic efficiency at the optimal applied potential of -1.0 V (vs. RHE) in a concentration of 0.1 M NO3--containing 0.1 M PBS. Furthermore, it demonstrates excellent electrochemical cycle stability. This work provides insights into the rational design and fabrication of ENO3RR electrocatalysts for potential electrocatalytic applications.

Gradient Hierarchical Hollow Heterostructures of Ti3C2Tx@rGO@MoS2 for Efficient Microwave Absorption.

Heterostructure engineering has emerged as a promising approach for creating high-performance microwave absorption materials in various applications such as advanced communications, portable devices, and military fields. However, achieving strong electromagnetic wave attenuation, good impedance matching, and low density in a single heterostructure remains a significant challenge. Herein, a unique structural design strategy that employs a hollow structure coupled with gradient hierarchical heterostructures to achieve high-performance microwave absorption is proposed. MoS2 nanosheets are uniformly grown onto the double-layered Ti3C2Tx MXene@rGO hollow microspheres through self-assembly and sacrificial template techniques. Notably, the gradient hierarchical heterostructures, comprising a MoS2 impedance matching layer, a reduced graphene oxide (rGO) lossy layer, and a Ti3C2Tx MXene reflective layer, have demonstrated significant improvements in impedance matching and attenuation capabilities. Additionally, the incorporation of a hollow structure can further improve microwave absorption while reducing the overall composite density. The distinctive gradient hollow heterostructures enable Ti3C2Tx@rGO@MoS2 hollow microspheres with exceptional microwave absorption properties. The reflection loss value reaches as strong as -54.2 dB at a thin thickness of 1.8 mm, and the effective absorption bandwidth covers the whole Ku-band, up to 6.04 GHz. This work provides an exquisite perspective on heterostructure engineering design for developing next-generation microwave absorbers.

[Distribution, Sources, and Behavioral Characteristics of Microplastics in Farmland Soil].

Microplastics (MPs) are widely present in farmland soil as an emerging contaminant. This paper serves as a comprehensive and systematic review of research progress on the characteristics of distribution, abundance, sources, shape, polymer composition, size, and migration of MPs in farmland soils around the world. Moreover, research prospects were also proposed. MPs have been detected in farmland soils around the world, mainly coming from agricultural plastic films, organic fertilizers, sludge, surface runoff, agricultural irrigation, atmospheric deposition, and tire wear particles. The morphology of MPs in soil mainly includes debris, fibers, and films. MPs polymer forms mainly include polyethylene, polypropylene, and polystyrene. Farmland land use significantly affects soil MPs abundance. Additionally, the abundance of MPs increase with the reduction in size. MPs in soil can migrate to deep soil through tillage, leaching, bioturbation, and gravity. Research on soil MPs detection methods, database establishment, safety thresholds, migration and transformation laws, potential ecological health risk assessment, and the construction of prevention and control technology systems should be strengthened in the future. The paper can provide a reference for the risk control and governance of farmland soil MPs pollution.

Hierarchical Ti3C2Tx@ZnO Hollow Spheres with Excellent Microwave Absorption Inspired by the Visual Phenomenon of Eyeless Urchins.

Ingenious microstructure design and rational composition selection are effective approaches to realize high-performance microwave absorbers, and the advancement of biomimetic manufacturing provides a new strategy. In nature, urchins are the animals without eyes but can "see", because their special structure composed of regular spines and spherical photosensitive bodies "amplifies" the light-receiving ability. Herein, inspired by the above phenomenon, the biomimetic urchin-like Ti3C2Tx@ZnO hollow microspheres are rationally designed and fabricated, in which ZnO nanoarrays (length: ~ 2.3 µm, diameter: ~ 100 nm) as the urchin spines are evenly grafted onto the surface of the Ti3C2Tx hollow spheres (diameter: ~ 4.2 µm) as the urchin spherical photosensitive bodies. The construction of gradient impedance and hierarchical heterostructures enhance the attenuation of incident electromagnetic waves. And the EMW loss behavior is further revealed by limited integral simulation calculations, which fully highlights the advantages of the urchin-like architecture. As a result, the Ti3C2Tx@ZnO hollow spheres deliver a strong reflection loss of - 57.4 dB and broad effective absorption bandwidth of 6.56 GHz, superior to similar absorbents. This work provides a new biomimetic strategy for the design and manufacturing of advanced microwave absorbers.

Tricomponent azide, tetrazolate, and carboxylate cobridging magnetic systems: ferromagnetic coupling, metamagnetism, and single-chain magnetism.

Three novel coordination polymers with azide and a bifunctional zwitterionic ligand bearing carboxylate and tetrazolate as bridging groups, [M(L)(N(3))]·xH(2)O [L=1-(carboxylatomethyl)-4-(5-tetrazolato)pyridinium, M=Cu (1, x=2), Ni (2, x=1), and Co (3, x=1)], have been synthesized and characterized by X-ray crystallography and magnetic measurements. The compounds consist of two-dimensional coordination layers in which uniform anionic chains with the unprecedented tricomponent (µ-azide)(µ-tetrazolate)(µ-carboxylate) bridges are cross-linked by cationic 1-methylenepyridinium spacers. The tricomponent bridges induce ferromagnetic interactions in all the compounds. Furthermore, this isostructural series of ferromagnetic-chain-based compounds has allowed us to observe distinct bulk properties that are dependent upon the natures of the different spin carriers: with the isotropic Cu(II) ion, 1 exhibits a paramagnetic phase of the ferromagnetic chains without long-range magnetic order above 2 K; with the weakly anisotropic Ni(II) ions, 2 displays antiferromagnetic ordering and field-induced metamagnetism without slow dynamic relaxation; and with Co(II), which has strong magnetic anisotropy due to first-order spin-orbital coupling, 3 exhibits magnetic hysteresis and slow magnetization dynamics typical of single-chain magnets.