Strong Interaction Research Articles

Arbutin attenuates CFA-induced arthritis by modulating expression levels of 5-LOX, NF‑κB, IL-17, PGE-2 and TNF-α.

Arbutin, a naturally soluble glycosylated phenol has antioxidant, antimicrobial, antitumor and anti-inflammatory properties. The current exploration appraises the treatment of arthritis by use of Arbutin (25, 50 and 100mg/kg) orally in CFA-induced rat arthritis model. Body weight changes, paw size, and joint diameter were recorded till the 28th day in the arthritic-induced rats. Hematological, biochemical, oxidative and inflammatory biomarkers were measured through the blood samples of anesthetized rats. Arbutin markedly decreased paw volume, PGE-2, anti-CCP and 5-LOX levels, however, maintained metabolic and hematological balance and prevented weight loss. Radiology and histology changes improved significantly in the ankle joints of rats. Moreover, Arbutin increased gene pointers such as IL-10 and IL-4 while significantly reducing the levels of CRP and WBCs, whereas Hb, platelets and RBCs count markedly raised in post-treatments. Antioxidant levels of SOD, CAT and GSH were improved and MDA level was reduced in treated groups. Rt-PCR investigation showed a significant reduction of the interleukin-1β, TNF-α, interleukin-6, cyclooxygenase-2, NF-κB and IL-17 and increased expression of gene pointers like IL-4, and IL-10 in treated groups. Assessment of molecular docking revealed a strong binding interaction of Arbutin against 5-LOX, IL-17, TNF-alpha and interleukin-6, cyclooxygenase-2, nuclear factor-κB, IL-4 and iNOS providing a strong association between experimental and theoretical results. As a result, Arbutin has significantly reduced CFA-induced arthritis by modulation of anti-inflammatory cytokines, i.e., IL-10 and IL-4, the pro-inflammatory cytokines panel such as NF-κB, TNF-alpha, IL-1β, IL-6, PGE-2, 5-LOX and COX-2 and oxidative biomarkers.

Tuning Adsorbate-Mediated Strong Metal-Support Interaction by Oxygen Vacancy: A Case Study in Ru/TiO2.

The adsorbate-mediated strong metal-support interaction (A-SMSI) offers a reversible means of altering the selectivity of supported metal catalysts, thereby providing a powerful tool for facile modulation of catalytic performance. However, the fundamental understanding of A-SMSI remains inadequate and methods for tuning A-SMSI are still in their nascent stages, impeding its stabilization under reaction conditions. Here, we report that the initial concentration of oxygen vacancy in oxide supports plays a key role in tuning the A-SMSI between Ru nanoparticles and defected titania (TiO2-x). Based on this new understanding, we demonstrate the in-situ formation of A-SMSI under reaction conditions, obviating the typically required CO2-rich pretreatment. The as-formed A-SMSI layer exhibits remarkable stability at various temperatures, enabling excellent activity, selectivity and long-term stability in catalyzing the reverse water gas-shift reaction. This study deepens the understanding of the A-SMSI and the ability to stabilize A-SMSI under reaction conditions represents a key step for practical catalytic applications.

Optical properties of lead-free Cs3Bi2I9 nanowire arrays prepared by template

Bismuth-based (Bi) perovskites have garnered significant interest as alternatives to lead-based (Pb) perovskites in photoelectric applications due to their non-toxicity and diverse structural properties. However, the inherent high limitation of electrons presents a significant challenge to their further utilization in various applications. Herein, all-inorganic Cs3Bi2I9 nanowire arrays have been successfully prepared by AAO template combined with the two-step method of low-temperature solution. Compared to the Cs3Bi2I9 film, the Cs3Bi2I9 nanowire arrays obtained the higher photoluminescence intensity, indicating a strong interaction between Cs3Bi2I9 and AAO, resulting from the significant weakening of the high electron confinement in the valence band of Cs3Bi2I9, which presenting as the valence band of the Cs3Bi2I9-AAO is mainly contributed by the O 2p orbital, while the conduction band does not change significantly. In addition, the Cs3Bi2I9 nanowire arrays have been demonstrated with the enhanced environmental and thermal stability, which maintain 90 % of their initial photoluminescence intensity after 120 h (in a vacuum) heating at 80 °C or after 10 days in the air (relative humidity of 40 %).

Crystal Facet Controlled Metal-Support Interaction in Uricase Mimics for Highly Efficient Hyperuricemia Treatment.

The effect of strong metal-support interaction (SMSI) has never been systematically studied in the field of nanozyme-based catalysis before. Herein, by coupling two different Pd crystal facets with MnO2, i.e., (100) by Pd cube (Pdc) and (111) by Pd icosahedron (Pdi), we observed the reconstruction of Pd atomic structure within the Pd-MnO2 interface, with the reconstructed Pdc (100) facet more disordered than Pdi (111), verifying the existence of SMSI in such coupled system. The rearranged Pd atoms in the interface resulted in enhanced uricase-like catalytic activity, with Pdc@MnO2 demonstrating the best catalytic performance. Theoretical calculations suggested that a more disordered Pd interface led to stronger interactions with intermediates during the uricolytic process. In vitro cell experiments and in vivo therapy results demonstrated excellent biocompatibility, therapeutic effect, and biosafety for their potential hyperuricemia treatment. Our work provides a brand-new perspective for the design of highly efficient uricase-mimic catalysts.

Exploring the Mechanisms behind Non-aromatic Fluorescence with the Density Functional Tight Binding Method.

Recent experimental findings reveal nonconventional fluorescence emission in biological systems devoid of conjugated bonds or aromatic compounds, termed non-aromatic fluorescence (NAF). This phenomenon is exclusive to aggregated or solid states and remains absent in monomeric solutions. Previous studies focused on small model systems in vacuum show that the carbonyl stretching mode along with strong interaction of short hydrogen bonds (SHBs) remains the primary vibrational mode explaining NAF in these systems. In order to simulate larger model systems taking into account the effects of the surrounding environment, in this work we propose using the density functional tight-binding (DFTB) method in combination with non-adiabatic molecular dynamics (NAMD) and the mixed quantum/molecular mechanics (QM/MM) approach. We investigate the mechanism behind NAF in the crystal structure of l-pyroglutamine-ammonium, comparing it with the related nonfluorescent amino acid l-glutamine. Our results extend our previous findings to more realistic systems, demonstrating the efficiency and robustness of the proposed DFTB method in the context of NAMD in biological systems. Furthermore, due to its inherent low computational cost, this method allows for a better sampling of the nonradiative events at the conical intersection which is crucial for a complete understanding of this phenomenon. Beyond contributing to the ongoing exploration of NAF, this work paves the way for future application of this method in more complex biological systems such as amyloid aggregates, biomaterials, and non-aromatic proteins.

Acoustic Resonance Tuning by High-Order Lorentzian Mixing.

Nanoscale mechanical resonators have attracted a great deal of attention for signal processing, sensors, and quantum applications. Recent progress in ultrahigh-Q acoustic cavities in nanostructures allows strong interactions with various physical systems and advanced functional devices. Those acoustic cavities are highly sensitive to external perturbations, and it is hard to control those resonance properties since those responses are determined by the geometry and material. In this paper, we demonstrate a novel acoustic resonance tuning method by mixing high-order Lorentzian responses in an optomechanical system. Using weakly coupled phononic-crystal acoustic cavities, we achieve coherent mixing of second- and third-order Lorentzian responses, which is capable of the fine-tunability of the bandwidth and peak frequency of the resonance with a tuning range comparable to the acoustic dissipation rate of the device. This novel resonance tuning method can be widely applied to Lorentzian-response systems and optomechanics, especially active compensation for environmental fluctuation and fabrication errors.

Recycled Iron Phosphates: A New Phosphorus Fertilizer for Paddy Rice.

The potential of recycled iron phosphates (FePs), e.g., vivianites (Fe3(PO4)2·8H2O) and Fe(III)-rich phosphorus (P) adsorbent materials, as phosphorus fertilizer is limited by the strong interaction between Fe and P. In this study, the efficiency of FePs as P fertilizer was explored by applying them as granules or powder in flooded strongly P-fixing soils (acid and calcareous), thereby taking advantage of increased P release induced by reductive dissolution of P-bearing Fe(III) minerals. First, no P diffusion from granular FeP fertilizers into flooded soils was detectable by the diffusive gradient in thin films (DGT) technique and microfocused X-ray fluorescence (μ-XRF) analysis of thin soil sections, in contrast to detectable P diffusion away from granules of soluble triple superphosphate (TSP) fertilizer. On the contrary, powdered FePs demonstrated an excellent increase in extractable P (1 mM CaCl2) in a 120-day incubation experiment in flooded soils. Second, a pot experiment was performed with rice (Oryza sativa) grown in flooded acid and calcareous soils. The fertilizer value of FePs was remarkable when dosed as powder, as it was even up to 3-fold higher than TSP in the acid soil and similar to TSP in the calcareous soil. The beneficial effect of FeP over TSP in the acid soil is attributed to the slow release of P from FePs, which allows to partly overcome P fixation. The promising results of FePs as P fertilizer applied as powders in flooded soils debunk the generally accepted idea that FePs are poor sources of P while demonstrating the importance of the timing of FeP fertilizer application.

Atomically Dispersed p-Block Aluminum-Based Catalysts for Oxygen Reduction Reaction.

The main group metals are commonly perceived as catalytically inert in the context of oxygen reduction reactions (ORR) due to the delocalized valence orbitals. Regulating the local environment and structure of metal center coordinated by nitrogen ligands (M-Nx) is a promising approach to accelerate catalytic dynamics. Herein, we, for the first time, report the atomically dispersed Al catalysts coordinated with N and C atoms for 4-electron ORR. The axial coordinated pyrrolyl N group (No) is constructed in the Al-N4-No moiety to regulate the p-band structure of Al center, effectively steering the local environment and structure of the square planar Al-N4 sites, which typically exhibit too strong interaction with ORR intermediates. The dynamic covalency competition of axial Al-No and Al-O bonding could endow the Al center with moderate hybridization between Al 3p orbital and O 2p orbital, alleviating the binding energy of ORR intermediates. The as-prepared Al-N4-No electrocatalyst exhibits excellent ORR activity, selectivity, and durability, along with the rapid kinetics as demonstrated by in situ Raman spectroscopy. This work offers a fundamental comprehension of the fine regulation on p-band and guides the rational design of main-group metal-based single atom catalysts.

Revealing Interaction of Fluorinated Propylamine Hydrochloride with Precursor and Defect States of Perovskite Films Toward Efficient Flexible Solar Cells

AbstractThe trap state at the surfaces and grain boundaries of perovskite is one of the major obstacles to the further commercialization of flexible perovskite solar cells (FPSCs). Herein, two innovative multifunctional fluorinated propylamine salt 2,2,3,3,3‐pentafluoropropylamine hydrochloride (PFPACl) and 3,3,3‐triflupropylamine hydrochloride (TFPACl) are in situ introduced onto the photo absorbing layer to improve the performance of the FPSCs. The nuclear magnetic resonance (NMR) spectroscopy indicates strong interactions of both PFPACl and TFPACl with the perovskite precursor components. For the first time, the structures of the supramolecular complexes formed by two additives with FAI are deduced from NOESY NMR data, thus pointing to the importance of the preorganization of the perovskite components in solution before film casting. The experiments and density functional theory（DFT) calculations reveal that PFPACl is likely dissociated more into the form of R‐NH3+‐Cl− due to the higher electronegativity of the fluoroalkyl tail. Therefore, PFPA+ binds more strongly to VFA defects than TFPA+, and anion Cl− has strong enough interaction with VFAI and uncoordinated Pb2+, leading to homogeneous coverage of PFPACl on the entire surface of the perovskite films and better energy alignment with the hole transport layer. Consequently, PFPACl‐treated FPSCs achieved a relatively high PCE of 23.59% with excellent mechanical robustness and operational stability.

Interlayer Potassium Single-Atom-Coordinated g-C3N4 for Significantly Boosted Visible Light Photocatalytic H2 Production.

In recent years, graphitic carbon nitride (g-C3N4) has attracted considerable attention because it includes earth-abundant carbon and nitrogen elements and exhibits good chemical and thermal stability owing to the strong covalent interaction in its conjugated layer structure. However, bulk g-C3N4 has some disadvantages of low specific surface area, poor light absorption, rapid recombination of photogenerated charge carriers, and insufficient active sites, which hinder its practical applications. In this study, we design and synthesize potassium single-atom (K SAs)-doped g-C3N4 porous nanosheets (CM-KX, where X represents the mass of KHP added) via supramolecular self-assembling and chemical cross-linking copolymerization strategies. The results show that the utilization of supramolecules as precursors can produce g-C3N4 nanosheets with reduced thickness, increased surface area, and abundant mesopores. In addition, the intercalation of K atoms within the g-C3N4 nitrogen pots through the formation of K-N bonds results in the reduction of the band gap and expansion of the visible-light absorption range. The optimized K-doped CM-K12 nanosheets achieve a specific surface area of 127 m2 g-1, which is 11.4 times larger than that of the pristine g-C3N4 nanosheets. Furthermore, the optimal CM-K12 sample exhibits the maximum H2 production rate of 127.78 μmol h-1 under visible light (λ ≥ 420 nm), which is nearly 23 times higher than that of bare g-C3N4. This significant improvement of photocatalytic activity is attributed to the synergistic effects of the mesoporous structure and K SAs doping, which effectively increase the specific surface area, improve the visible-light absorption capacity, and facilitate the separation and transfer of photogenerated electron-hole pairs. Besides, the optimal sample shows good chemical stability for 20 h in the recycling experiments. Density functional theory calculations confirm that the introduction of K SAs significantly boosts the adsorption energy for water and decreases the activation energy barrier for the reduction of water to hydrogen.

Thermal‐mechanical properties of bamboo charcoal/recycled low‐density polyethylene composites

AbstractBamboo fiber has garnered considerable attention owing to its high specific strength and renewability. However, the hydrophilic nature of the material must be carefully managed to create a bamboo composite with usable thermal‐mechanical properties. Herein, the NaOH‐treated bamboo fiber (particle size ≤200 μm) was used to produce bamboo charcoal (BC). Then, recycled low‐density polyethylene containing BC composites was fabricated by varying the BC composition (between 2 and 8 wt%). Effects of different BC wt% in the BC/recycled low‐density polyethylene composites (denoted as xBCPE, where x indicates BC wt% in the composites) were analyzed for tensile strength, morphology, and thermal properties. In addition, the water absorption capacities of the BCPE composites were compared. These xBCPE composites showed excellent thermal stability and low water absorption properties. Therefore, they are potential candidate materials for electrical device packaging with partial degradability.Highlights Bamboo charcoal (BC) was prepared via low‐temperature pyrolysis of alkaline‐treated bamboo fiber. BC displayed strong interfacial interaction with recycled low‐density polyethylene. Proportion of BC on the composite properties was investigated and furnished. The xBCPE composites demonstrate low water absorption and excellent thermal stability. The reinforced composite (4BCPE) shows great promise as a functional material.

High-Entropy Prussian Blue Analogues Enable Lattice Respiration for Ultra-Stable Aqueous Aluminum-Ion Batteries.

Aqueous aluminum ion batteries (AAIBs) hold significant potential for grid-scale energy storage owing to their intrinsic safety, high theoretical capacity, and abundance of aluminum. However, the strong electrostatic interactions and delayed charge compensation between high-charge-density aluminum ions and the fixed lattice in conventional cathodes impede the development of high-performance AAIBs. To address this issue, we introduce, for the first time, high-entropy Prussian blue analogs (HEPBAs) as cathodes in AAIBs with unique lattice tolerance and efficient multipath electron transfer. Benefiting from the intrinsic long-range disorder and robust lattice strain field, HEPBAs enable the manifestation of the lattice respiration effect and minimize lattice volume changes, thereby achieving one of the best long-term stabilities (91.2% capacity retention after 10,000 cycles at 5.0 A g-1) in AAIBs. Additionally, the interaction between the diverse metal atoms generates a broadened d-band and reduced degeneracy compared with conventional PBAs, which enhances the electron transfer efficiency with one of the best rate performance (79.2 mAh g-1 at 5.0 A g-1) in AAIBs. Furthermore, exceptional element selectivity in HEPBAs with unique cocktail effect could facile tune electrochemical behavior. Overall, the newly developed HEPBAs with a high-entropy effect exhibit promising solutions for advancing AAIBs and multivalent-ion batteries. This article is protected by copyright. All rights reserved.

Interfacial Super‐Assembly of Vacancy Engineered Ultrathin‐Nanosheets toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion

Ion‐selective nanochannel membranes assembled from two‐dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy‐engineered, oxygen‐deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers‐wrapped carbon nanotubes (VOLDH/CNF‐CNT) composite membrane. This membrane, featuring abundant angstrom‐scale, cation‐selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super‐assembly. The membrane shows interlayer free‐spacing of ~3.62 Å, which validates the membrane size exclusion selectivity.This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high‐power density of 5.35 W/m2 with long‐term durability (20,000s), which is almost 400% higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH‐ and temperature‐sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high‐performance salinity gradient power conversion and underscores the potential of vacancy engineering and super‐assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Interfacial Super-Assembly of Vacancy Engineered Ultrathin-Nanosheets toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion.

Ion-selective nanochannel membranes assembled from two-dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy-engineered, oxygen-deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers-wrapped carbon nanotubes (VOLDH/CNF-CNT) composite membrane. This membrane, featuring abundant angstrom-scale, cation-selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super-assembly. The membrane shows interlayer free-spacing of ~3.62 Å, which validates the membrane size exclusion selectivity.This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high-power density of 5.35 W/m2 with long-term durability (20,000s), which is almost 400% higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH- and temperature-sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high-performance salinity gradient power conversion and underscores the potential of vacancy engineering and super-assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

Insights into PVC-promoted hydrothermal carbonization of manure: Dechlorination, inorganic metals removal, and combustion behaviors

Hydrothermal carbonization (HTC) can serve as a promising route to effectively co-valorize biomass and plastic wastes for solid fuel production. However, manure-derived hydrochar for fuel application remains a significant challenge due to its high ash content and low energy density. Polyvinyl chloride (PVC), as a chlorine-containing plastic, subjected to HTC commonly results in the generation of massive acidic wastewater. Herein, we proposed a PVC-promoted HTC route for high energy–density hydrochar production. By utilizing PVC as an in situ acidic additive, the HTC condition was optimized at 275 °C, 30 min, with a PVC addition of 10 %. The hydrochar obtained under the optimized condition exhibited a higher heating value (HHV) of 25.89 MJ/kg, comparable to bituminous coals, and achieve a high energy recovery rate of nearly 70 %. Moreover, the excellent removal efficiencies of inorganic metals and chlorine both exceeding 95 % (except for Fe at 86 %) were observed, owing to the strong interactions between dechlorination and inorganic metals removal. Importantly, it was evidenced that acidic reaction environment was demonstrated to enhance the carbonization degree and modify the hydrochar formation mechanism. Furthermore, the high comprehensive combustion index S of 3.22 × 10−7 %2/( °C3·min2) and low average Ea of 134.20 kJ/mol were achieved, indicating the favorable combustion behaviors. Overall, this work systematically and comprehensively investigated the PVC-promoted HTC of manure waste for advanced solid fuel production and examined its combustion characteristics, unveiling the hydrochar formation mechanism.

A Hybrid-Salt Strategy for Modulating the Li+ Solvation Sheathes and Constructing Robust SEI in Non-Flammable Electrolyte Lithium Metal Batteries.

The electrode interface determines the performance of an electrochemical energy storage system. Using traditional electrolyte organic additives and high-concentration electrolyte emerging recently are two generally strategies for improving the electrode interface. Here, a hybrid-salt electrolyte strategy is proposed for constructing the stable electrode interface. Through the solubilization effect of phosphate ester on LiNO3, a hybrid-salts-based non-flammable phosphate ester electrolyte system (HSPE) with LiPF6 and LiNO3 as Li salts has been developed. By the strong interaction between NO3 - and Li+, the Li+ solvation sheath and solvent behaviors have been modulated, thus the undesirable effects of phosphate ester are eliminated and a robust SEI is formed. Experimental results and theoretical calculations illustrate that NO3 - as a kind of strongly coordinating anion can reduce the number of TEP molecules and lower the reduction reactivity of TEP. The reconfigured Li+ solvation structure allows the formation of an inorganic-rich SEI on the electrode surface. As a result, in the designed HSPE, the average coulombic efficiency of lithium plating/stripping is increased to 99.12 %. This work explored a new approach to construct the electrode interface and addressing the poor interface performance issue of phosphate esters.

One-pot synthesis of novel polyvinylphosphonic acid hydrogels for efficient separation of low-enriched uranium in water

Uranium extraction from seawater and the treatment of radioactive wastewater has traditionally been a hot topic. Herein, p(VPA-AM)n solid hydrogels with high uranium extraction properties based on vinylphosphonic acid (VPA) were successfully prepared by one-step copolymerization for the first time. The batch adsorption experiments demonstrated that p(VPA-AM)n has strong uranium chelating ability, fast uranium adsorption kinetics (within 200 min) and high uranium adsorption capacity (644.67 mg/g), and its adsorption behavior conforms to the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model, which is a spontaneous heat-absorbing chemical monolayer adsorption process. After 15 adsorption–desorption tests, the adsorption capacity was kept above 96 % of the original capacity, and the uranium extracted from the salt lake water achieved at 3.56 mg/g, which showed superb behavior in treating complex uranium systems. Mechanism studies revealed that the strong interaction between UO22 + and −PO43- dominated the adsorption and the robust complexation might have led to the electron transfer in the structure. The maximum uranium removal rate of p(VPA-AM)n in simulated seawater reached 90 %, and the simple in situ zinc oxide-modified p(VPA-AM)n hydrogel showed good anti-biosludge properties against three common bacteria (E. coli, B. subtilis and S. aureus), which has a great potential for application in seawater uranium extraction and uranium wastewater treatment.

Doubly charmed pentaquark states in QCD sum rules

We have studied the mass spectra of doubly charmed pentaquark states in the Λc(*)D(*) and Σc(*)D(*) channels with JP=1/2±, 3/2±, and 5/2± within the framework of quantum chromodynamics sum rules. We use the parity projected sum rules to separate the contributions of negative and positive parities from the two-point correlations induced by the pentaquark interpolating currents. Our results show that the bound states of Pcc pentaquarks may exist in the ΛcD(12−), ΣcD(12−), ΣcD*(32−), Λc*D(32−), Λc*D*(52−) channels with negative-parity and ΣcD(12+), ΣcD*(32+), Σc*D(32+) channels with positive-parity, since their masses are predicted to be lower than the corresponding meson-baryon thresholds. However, they are still allowed to decay into the Ξcc(*)π final states via strong interaction. The triply charged Pcc+++(ccuud¯) and neutral Pcc0(ccddu¯) in the isospin quartet would definitely be pentaquark states due to their exotic charges. We suggest searching for these characteristic doubly charmed pentaquark signals in the Pcc+++→Ξcc(*)++π+/ρ+, Σc(*)++D(*)+ and Pcc0→Ξcc(*)+π−/ρ−, Σc(*)0D(*)0 decays in the near future. Published by the American Physical Society 2024

Molten salt induced strong interaction between Co3O4 and montmorillonite for the promoted peroxymonosulfate activation toward tetracycline degradation

Cobalt-based materials exhibit great premises for activating peroxymonosulfate (PMS) toward water remediation. Generally, active Co species are anchored on the surface of supports to improve the utilization efficiency, yet the stability of the catalyst is difficult to resolve due to the weak interaction between the active species and the support. Herein, a molten salt method is employed to reinforce the interfacial interaction between Co3O4 and montmorillonite (Mt) support. The use of molten Na3PO4 can mitigate the dehydroxylation process of Mt, and thus the electronic structure of Co3O4 NPs can be regulated by the surface hydroxyl species more efficiently. Consequently, the prepared Co3O4/Mt displays an enhanced CoII/CoIII ratio, and the degradation of tetracycline (TC) could reach 99% in 7 min by the PMS-based advanced oxidation process. Meanwhile, the TC removal efficiency can still reach 96% after 8 cycles, and the Co ion leaching is over 10 times lower as compared with the catalyst prepared not using the molten salt. This study highlights the significance of the molten salt method for enhancing the strong interfacial interaction, which is crucial to regulating the nature of supported catalysts, and provide satisfactory Co-based catalyst for PMS activation toward TC degradation.

Introduction of element Bi in the P-block promotes N2 activation for efficient electrocatalytic nitrogen reduction to produce ammonia

The synthesis of ammonia through electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions is a presumable strategy. However, it still faces the problems of poor activity and low Faradic efficiency, so the development of efficient, stable and highly selective catalysts is of the importance. Molybdenum disulfide (MoS2) materials are widely used in NRR reactions owing to good electrical conductivity and abundant active sites, but the edge active site is the dual active site of NRR and competitive hydrogen evolution reaction (HER). Encouragingly, the strong interaction between elements in the P-block and N 2p orbitals results in excellent performance in adsorbing and activating nitrogen. Meanwhile, the partial occupation of p-orbitals by elements in the P-block also leads to poor HER activity. Herein, we introduced the P-block element Bi into 1 T-MoS2 and prepared Bi2S3/MoS2 composite. Taking advantage of the high conductivity of 1 T-MoS2 and the N2 adsorption and activation advantages of Bi element, an ammonia yield rate of 54.64 µg h−1 mg−1cat. and a high Faradic efficiency of 58.56 % were obtained. In addition, the active site and the evolution pathway of N2 reduction were investigated by in-situ infrared spectroscopy measurements and density functional theory (DFT). The in-situ infrared spectroscopy measurement results manifested the presence of the main intermediate transition state during the reduction of N2 to NH3. The calculation results indicated that N2 had the best adsorption on the introduced P-block element Bi, and the entire NRR reaction process followed an alternating pathway. This study reveals the synergistic effect of P-block elements and transition metal-based electrocatalytic materials on nitrogen reduction to ammonia synthesis.