Ultra-efficient peroxymonosulfate utilization and trichloroethylene degradation in heterogeneous catalytic system guided by sheet-like Cu2MnO4 nanoparticles: The role of Cu(III)-O species and free radicals.

Synthesizing cubic spinel Cu2MnO4 with nanosheet structure (SCMO) aimed to construct a "non-radical-mediated radical-oxidative reaction", for increasing PMS utilization efficiency, and solving the defects of SO4•- and •OH through indirect PMS activation by electron transfer process. Compared with box-like Cu2MnO4 (11.1%, 0.0035 min-1) and ordinary Cu2MnO4 nanoparticles (21.3%, 0.0070 min-1), SCMO/PMS showed excellent trichloroethylene removal (98.8%, 0.1577 min-1). The pivotal role of Cu(III) was determined based on EPR analysis, quenching experiments, chemical probe experiments, hydrogen temperature-programmed reduction and Raman spectroscopy analysis, in-situ FTIR and Raman analyses. In brief, the interaction between PMS and SCMO could produce surface-bonded reactive complexes and the subsequent breaking of O-O bond in the sub-stable structure allowed the conversion of Cu(II) to Cu(III), which in turn facilitates the generation of •OH and SO4•-. The density functional theory (DFT) calculations provided supporting evidence for the electron donor role of SCMO and the increase of the electron acceptance capacity of PMS. SCMO/PMS system showed good resistance and degradation efficiency to complex composition and combined pollutants in actually contaminated groundwater, respectively. However, the coexistence of high concentrations of arsenic could significantly affect SCMO performance due to their adsorption on -OH groups, which still need in-depth study.

The Three-Dimensional Hierarchical Structure of Bi x -Sn1-x O2 Used for Ultrasensitive Detection of Butanone under UV Irradiation.

Recent studies have identified butanone as a promising biomarker in the breath of lung cancer patients, yet the understanding of its gas-sensing properties remains limited. A key challenge has been to enhance the gas-sensing performance of materials toward butanone, particularly under ultraviolet light exposure. Herein, we report the synthesis of a novel three-dimensional composite material composed of SnO2 incorporated with Bi2O3 using facile hydrothermal and impregnation precipitation methods. Detailed physical and chemical characterizations were performed to assess the properties of the developed material. Upon activation with ultraviolet light, our composite exhibited exceptionally high sensitivity to butanone. Remarkably, the butanone response was nearly 3 times greater for the Bi2O3-loaded SnO2 composite than for pristine SnO2, achieving a response value of 70. This substantial improvement is due to the synergistic effect of the material's distinctive three-dimensional architecture and the presence of Bi2O3, which significantly augmented the gas-sensing capability of butanone. To elucidate the underlying gas-sensing mechanism, we conducted first-principles calculations using density functional theory (DFT). The computational analysis revealed that the Bi2O3-containing system possesses superior adsorption energy for butanone. Ultimately, our findings suggest that the Bi-SnO2 composite holds great promise as an optimal sensing material for the detection of butanone under ultraviolet illumination.

One-to-Nine Single Spectroscopic Intelligent Probe for Risk Assessment of Multiple Metals in Drinking Water.

26% of the world's population lacks access to clean drinking water; clean water and sanitation are major global challenges highlighted by the UN Sustainable Development Goals, indicating water security in public water systems is at stake today. Water monitoring using precise instruments by skilled operators is one of the most promising solutions. Despite decades of research, the professionalism-convenience trade-off when monitoring ubiquitous metal ions remains the major challenge for public water safety. Thus, to overcome these disadvantages, an easy-to-use and highly sensitive visual method is desirable. Herein, an innovative strategy for one-to-nine metal detection is proposed, in which a novel thiourea spectroscopic probe with high 9-metal affinity is synthesized, acting as "one", and is detected based on the 9 metal-thiourea complexes within portable spectrometers in the public water field; this is accomplished by nonspecialized personnel as is also required. During the processing of multimetal analysis, issues arise due to signal overlap and reproducibility problems, leading to constrained sensitivity. In this innovative endeavor, machine learning (ML) algorithms were employed to extract key features from the composite spectral signature, addressing multipeak overlap, and completing the detection within 30-300 s, thus achieving a detection limit of 0.01 mg/L and meeting established conventional water quality standards. This method provides a convenient approach for public drinking water safety testing.

Enhancing heterogeneous Fenton-like catalysis through pyrrolidine modification of Fe2O3-CuO composites with oxygen-vacancy defects.

Enhancing the generation of reactive hydroxyl radicals (•OH) is crucial for overcoming the limitations of the low reactivity of heterogeneous Fenton Fe-based catalysts. Researchers have explored various methods to modify catalyst structures to enhance reactivity, yet often at the expense of stability. Herein, suitable carbon and nitrogen-codoped Fe2O3-CuO composites were synthesized via pyrolysis method, demonstrating high Fenton reaction activity and remarkable stability. Experimental findings and density functional theory calculations (DFT) revealed that the presence of oxygen vacancies on the catalyst surface facilitated an increase in exposed FeNC active sites, promoting electron transfer and the accelerating the rate of •OH generation. Moreover, carbon and nitrogen, particularly in the form of pyrrole nitrogen bonded to Fe imparted exceptional stability to the FeNC active sites, mitigating their dissolution. Additionally, the Fe-based catalysts exhibited strong magnetism, enabling easy separation from the reaction solution while maintaining a high degradation efficiency for various organic pollutants, even in the presence of multiple anions. Furthermore, a comprehensive mechanism for methylene blue (MB) degradation was identified, enhancing the potential practical applications of these catalysts.

Reactive P and S co-doped porous hollow nanotube arrays for high performance chloride ion storage.

Developing stable, high-performance chloride-ion storage electrodes is essential for energy storage and water purification application. Herein, a P, S co-doped porous hollow nanotube array, with a free ion diffusion pathway and highly active adsorption sites, on carbon felt electrodes (CoNiPS@CF) is reported. Due to the porous hollow nanotube structure and synergistic effect of P, S co-doped, the CoNiPS@CF based capacitive deionization (CDI) system exhibits high desalination capacity (76.1 mgCl- g-1), fast desalination rate (6.33 mgCl- g-1 min-1) and good cycling stability (capacity retention rate of > 90%), which compares favorably to the state-of-the-art electrodes. The porous hollow nanotube structure enables fast ion diffusion kinetics due to the swift ion transport inside the electrode and the presence of a large number of reactive sites. The introduction of S element also reduces the passivation layer on the surface of CoNiP and lowers the adsorption energy for Cl- capture, thereby improving the electrode conductivity and surface electrochemical activity, and further accelerating the adsorption kinetics. Our results offer a powerful strategy to improve the reactivity and stability of transition metal phosphides for chloride capture, and to improve the efficiency of electrochemical dechlorination technologies.

Quantitative Insights into Phosphate-Enhanced Lead Immobilization on Goethite.

Despite extensive study, geochemical modeling often fails to accurately predict lead (Pb) immobilization in environmental samples. This study employs the Charge Distribution MUlti-SIte Complexation (CD-MUSIC) model, X-ray absorption fine structure (XAFS), and density functional theory (DFT) to investigate mechanisms of phosphate (PO4) induced Pb immobilization on metal (hydr)oxides. The results reveal that PO4 mainly enhances bidentate-adsorbed Pb on goethite via electrostatic synergy at low PO4 concentrations. At relatively low pH (below 5.5) and elevated PO4 concentrations, the formation of the monodentate-O-sharing Pb-PO4 ternary structure on goethite becomes important. Precipitation of hydropyromorphite (Pb5(PO4)3OH) occurs at high pH and high concentrations of Pb and PO4, with an optimized log Ksp value of -82.02. The adjustment of log Ksp compared to that in the bulk solution allows for quantification of the overall Pb-PO4 precipitation enhanced by goethite. The CD-MUSIC model parameters for both the bidentate Pb complex and the monodentate-O-sharing Pb-PO4 ternary complex were optimized. The modeling results and parameters are further validated and specified with XAFS analysis and DFT calculations. This study provides quantitative molecular-level insights into the contributions of electrostatic enhancement, ternary complexation, and precipitation to phosphate-induced Pb immobilization on oxides, which will be helpful in resolving controversies regarding Pb distribution in environmental samples.

Multi-interface interaction mechanism of pulp reject-based flocculants for the removal of antibiotics and its combined pollutants.

The efficient removal of antibiotics and its combined pollutants is essential for aquatic environment and human health. In this study, a lignin-based organic flocculant named PRL-VAc-DMC was synthesized using pulp reject as the raw material, with vinyl acetate (VAc) and methacryloxyethyltrimethyl ammonium chloride (DMC) as the grafting monomers. A series of modern characterization methods were used to confirm the successful preparation of PRL-VAc-DMC and elucidate its polymerization mechanism. It was found that the Ph-OH group and its contiguous carbon atoms of lignin served as the primary active sites to react with grafting monomers. Flocculation experiments revealed that PRL-VAc-DMC could react with tetracycline (TC) through π-π* interaction, hydrophobic interaction, hydrogen bonding, and electrostatic attraction. With the coexistence of humic acid (HA) and Kaolin, the aromatic ring, hydroxyl, and amide group of TC could react with the benzene ring, hydroxyl group, and carboxyl group of HA, forming TC@HA@Kaolin complexes with Kaolin particles acting as the hydrophilic shell. The increase in particle size, electronegativity, and hydrophily of TC@HA@Kaolin complexes facilitated their interaction with PRL-VAc-DMC through strong interfacial interactions. Consequently, the presence of HA and Kaolin promoted the removal of TC. The synergistic removal mechanism of TC, HA, and Kaolin by PRL-VAc-DMC was systematically analyzed from the perspective of muti-interface interactions. This paper is of great significance for the comprehensive utilization of pulp reject and provides new insights into the flocculation mechanism at the molecular scale.

Novel chitosan-modified biochar prepared from a Chinese herb residue for multiple heavy metals removal: Characterization, performance and mechanism.

In this study, the sorption properties of Cr(VI), As(III), and Pb(II) on chitosan-modified magnetic biochar (CMBC) derived from residues of Ligusticum chuanxiong Hort. were investigated. CMBC was found to be a valuable material for removing three heavy metals from water simultaneously. Kinetic analysis suggested Cr(VI), As(III), and Pb(II) were chemisorbed onto CMBC, while isotherm data conformed well to Langmuir model, the maximum adsorption capacity of CMBC was found to be 65.74 mg/g for Cr(VI), 49.32 mg/g for As(III), and 69.45 mg/g for Pb(II). Experiments, characterization, and density functional theory (DFT) calculations were employed to explore the mechanisms. Furthermore, CMBC demonstrated excellent removal rates of over 95% for Cr(VI), 99% for As(III) and Pb(II) from contaminated water bodies. This work shows that CMBC holds significant potential for wastewater treatment of heavy metals and provides an effective solution for the utilization of Chinese herb residues in environmental remediation.

Three-Dimensional Metal-Organic Framework@Cellulose Skeleton-Reinforced Composite Polymer Electrolyte for All-Solid-State Lithium Metal Battery.

High-safety and high-energy-density solid-state lithium metal batteries (SSLMBs) attract tremendous interest in both academia and industry. Especially, composite polymer electrolytes (CPEs) can overcome the limitations of single-component solid-state electrolytes. In this work, a strategy of combining a rigid functional skeleton with a soft polymer electrolyte to prepare reinforced CPEs was adopted. The in situ grown zeolitic imidazolate frameworks (ZIFs) with three-dimensional cellulose fiber skeleton (ZIF-67@CF) and succinonitrile (SN) plasticizer into poly(ethylene oxide) (PEO) together form ZIF-67@CF/PEO-SN CPEs. The addition of ZIF-67@CF and SN to PEO synergistically enhanced the physical and electrochemical properties of CPEs. Furthermore, the conduction mechanism of lithium-ion (Li+) in CPEs was studied using density functional theory. It is impressive that the ZIF-67@CF/PEO-SN CPEs at 30 °C exhibit a high ionic conductivity of 1.17 × 10-4 S cm-1, a competitive Li+ transference number of 0.40, a wide electrochemical window of 5.0 V, a notable tensile strength of 18.7 MPa, and superior lithium plating/stripping stability (>550 h at 0.1 mA cm2). Such favorable features endowed LiFePO4/(ZIF-67@CF/PEO-SN)/Li cell at 30 °C with a high discharging capacity (152.5 mA h g-1 at 0.2 C), a long cycling lifespan (>150 cycles with 99% capacity retention), and superior operating safety. This work provides insights and promotes the application of functionalized CPEs for SSLMBs.

Abundant Edge Active Sites-Modified High-Crystalline g-C3N5 for Hydrogen Peroxide Production from Pure-Water via a Quasi-Homogeneous Photocatalytic Process.

Ultrathin carbon nitride pioneered a paradigm that facilitates effective charge separation and acceleration of rapid charge migration. Nevertheless, the dissociation process confronts a disruption owing to the proclivity of carbon nitride to reaggregate, thereby impeding the optimal utilization of active sites. In response to this exigency, the adoption of a synthesis methodology featuring alkaline potassium salt-assisted molten salt synthesis is advocated in this work, aiming to craft a nitrogenated graphitic carbon nitride (g-C3N5) photocatalyst characterized by thin layer and hydrophilicity, which not only amplifies the degree of crystallization of g-C3N5 but also introduces a plethora of abundant edge active sites, engendering a quasi-homogeneous photocatalytic system. Under visible light irradiation, the ultra-high H2O2 production rate of this modified high-crystalline g-C3N5 in pure water attains 151.14 µm h-1. This groundbreaking study offers a novel perspective for the innovative design of highly efficient photocatalysts with a quasi-homogeneous photocatalytic system.

Boosting the Electrochemical Performance of Primary and Secondary Lithium Batteries with Mn-Doped All-Fluoride Cathodes.

Transition metal fluorides are potentially high specific energy cathode materials of next-generation lithium batteries, and strategies to address their low conductivity typically involve a large amount of carbon coating, which reduces the specific energy of the electrode. In this study, MnyFe1-yF3@CFx was generated by the all-fluoride strategy, converting most of the carbon in MnyFe1-yF3@C into electrochemical active CFx through a controllable NF3 gas phase fluorination method, while still retaining a tightly bound graphite layer to provide initial conductivity, which greatly improved the energy density of the composite. This synergistic effect of nonfluorinated residual carbon (∼11%) and Mn doping ensures the electrochemical kinetics of the composite. The loading mass of the active substance had been increased to 86%. The theoretical and actual discharge capacity of MnyFe1-yF3@CFx composite was up to 765 mAh g-1 (pure FeF3 is 712 mAh g-1) and 728 mAh g-1, respectively. The discharge capacity at the high-voltage (3.0 V) platform was more than three times higher than that of the non-Mn-doped composite (FeF3@CFx).

Supercapacitor Performance of Sulfonyldibenzene Derivative-Functionalized Graphene Aerogel.

3D aerogels incorporating functionalized reduced graphene oxide (SUL/rGO) were prepared as a hydrothermal method utilizing graphene oxide (GO) and a sulfonyldibenzene derivative (SUL) as raw materials. The aromatic compound SUL, which contains hydroxyl and sulfonyl groups, was bonded to reduced graphene oxide (rGO) through π-π connections. The obtained composite material exhibited porosity within its structure with improved hydrophilicity, along with excellent electrochemical characteristics. This improvement was ascribed to the specific rGO structure, as well as the pseudocapacitance inherent in SUL, both of which synergistically contribute to improvement in the characteristics of the prepared electrode materials. Also, an analysis was performed employing density functional theory from which the density of states and adsorption energy of SUL on the surface of rGO were computed to further investigate the charge storage process within the prepared composite. The prepared SUL/rGO-2 electrode exhibited the highest specific capacitance value of 388 F/g at a current density equal to 1 A/g. The constructed symmetrical supercapacitor, SUL/rGO-2//SUL/rGO-2, attained an energy density value of 14.55 Wh/kg at a power density equal to 350 W/kg with an exceptional galvanostatic charge-discharge (GCD) cyclic stability equal to 91% following 10 000 cycles. Therefore, this review presents a novel functionalized graphene-based material incorporating hydroxyl and sulfonyl groups, which holds promise in future energy storage applications.

3D/1D Fe3O4@TiO2/TC-TiO2/SiO2 Magnetic Inorganic-Framework Molecularly Imprinted Fibers for Targeted Photodegradation.

To achieve a selective degradation of pollutants in a water body, 3D/1D magnetic molecularly imprinted fibers Fe3O4@TiO2/TC-TiO2/SiO2 were fabricated by an electrospinning method. The molecularly imprinted layer was successfully prepared by a direct imprinting method using TiO2 as a functional monomer. Fe3O4 facilitates the catalyst recovery and light utilization. The as-prepared fibrous photocatalyst has a large specific surface area of 132.4 m2/g. The successful generation of imprinted sites was proven by various characterizations. The weak interaction between the inorganic functional monomer and tetracycline (TC) was determined to be van der Waals force and hydrogen bonds by the IGMH isosurface theory. The construction of the 3D/1D homojunction of molecularly imprinted materials is beneficial to charge transfer. The as-prepared photocatalyst exhibits a high selectivity coefficient α = 737.38 competing with RhB. The TC removal efficiency reached 100% within only 20 min. In addition, the possible degradation pathway and the degradation mechanism are reasonably proposed. This work not only provides an in-depth mechanism of the weak interaction between the inorganic molecularly imprinted functional monomer and pollutant molecules but also offers new thoughts on the fabrication of photocatalysts for the effective and selective treatment of pollutants in water bodies.

Interlayer Structure Manipulation of FeOCl/MXene with Soft/Hard Interface Design for Safe Water Production Using Dechlorination Battery Deionization.

Suffering from the susceptibility to decomposition, the potential electrochemical application of FeOCl has greatly been hindered. The rational design of the soft-hard material interface can effectively address the challenge of stress concentration and thus decomposition that may occur in the electrodes during charging and discharging. Herein, interlayer structure manipulation of FeOCl/MXene using soft-hard interface design method were conducted for electrochemical dechlorination. FeOCl was encapsulated in Ti3C2Tx MXene nanosheets by electrostatic self-assembly layer by layer to form a soft-hard mechanical hierarchical structure, in which Ti3C2Tx was used as flexible buffer layers to relieve the huge volume change of FeOCl during Cl- intercalation/deintercalation and constructed a conductive network for fast charge transfer. The CDI dechlorination system of FeOCl/Ti3C2Tx delivered outstanding Cl- adsorption capacity (158.47 ± 6.98 mg g-1), rate (6.07 ± 0.35 mg g-1 min-1), and stability (over 94.49 % in 30 cycles), and achieved considerable energy recovery (21.14 ± 0.25 %). The superior dechlorination performance was proved to originate from the Fe2+/Fe3+ topochemical transformation and the deformation constraint effect of Ti3C2Tx on FeOCl. Our interfacial design strategy enables a hard-to-soft integration capacity, which can serve as a universal technology for solving the traditional problem of electrode volume expansion.

Mesoporous cobalt-manganese layered double hydroxides promote the activation of calcium sulfite for degradation and detoxification of metronidazole.

Metronidazole (MNZ), a commonly used antibiotic, poses risks to water bodies and human health due to its potential carcinogenic, mutagenic, and genotoxic effects. In this study, mesoporous cobalt-manganese layered double hydroxides (CoxMny-LDH) with abundant oxygen vacancies (Ov) were successfully synthesized using the co-precipitation method and used to activate calcium sulfite (CaSO3) with slight soluble in water for MNZ degradation. The characterization results revealed that Co2Mn-LDH had higher specific areas and exhibited good crystallinity. Co2Mn-LDH/CaSO3 exhibited the best catalytic performance under optimal conditions, achieving a remarkable MNZ degradation efficiency of up to 98.1 % in only 8 min. Quenching experiments and electron paramagnetic resonance (EPR) tests showed that SO4•- and 1O2 played pivotal roles in the MNZ degradation process by activated CaSO3, while the redox cycles of Co2+/Co3+ and Mn3+/Mn4+ on the catalyst surface accelerated electron transfer, promoting radical generation. Three MNZ degradation routes were put forward based on the density functional theory (DFT) and liquid chromatography-mass spectrometer (LC-MS) analysis. Meanwhile, the toxicity analysis result demonstrated that the toxicity of intermediates post-catalytic reaction was decreased. Furthermore, the Co2Mn-LDH/CaSO3 system displayed excellent stability, reusability, and anti-interference capability, and achieved a comparably high removal efficiency across various organic pollutant water bodies. This study provides valuable insights into the development and optimization of effective heterogeneous catalysts for treating antibiotic-contaminated wastewater.

High-performance electrosorption of lanthanum ion by Mn3O4-loaded phosphorus-doped porous carbon electrodes via capacitive deionization.

Transition-metal-oxide@heteroatom doped porous carbon composites have attracted considerable research interest because of their large theoretical adsorption capacity, excellent electrical conductivity and well-developed pore structure. Herein, Mn3O4-loaded phosphorus-doped porous carbon composites (Mn3O4@PC-900) were designed and fabricated for the electrosorption of La3+ in aqueous solutions. Due to the synergistic effect between Mn3O4 and PC-900, and the active sites provided by Mn-O-Mn, C/PO, C-P-O and Mn-OH, Mn3O4@PC-900 exhibits high electrosorption performance. The electrosorption value of Mn3O4@PC-900 was 45.34% higher than that of PC-900, reaching 93.02 mg g-1. Moreover, the adsorption selectivity reached 87.93% and 89.27% in La3+/Ca2+ and La3+/Na+ coexistence system, respectively. After 15 adsorption-desorption cycles, its adsorption capacity and retention rate were 50.34 mg g-1 and 54.12%, respectively. The electrosorption process is that La3+ first accesses the pores of Mn3O4@PC-900 to generate an electric double layer (EDL), and then undergoes further Faradaic reaction with Mn3O4 and phosphorus-containing functional groups through intercalation, surface adsorption and complexation. This work is hoped to offer a new idea for exploring transition-metal-oxide @ heteroatom doped porous carbon composites for separation and recovery of rare earth elements (REEs) by capacitive deionization.

Enhancing the supercapacitive performance of a carbon-based electrode through a balanced strategy for porous structure, graphitization degree and N,B co-doping.

Regarding carbon-based electrodes, simultaneously establishing a well-defined meso-porous architecture, introducing abundant hetero-atoms and improving the graphitization degree can effectively enhance their capacitive performance. However, it remains a significant challenge to achieve a good balance between defects and graphitization degree. In this study, the porous structure and composition of carbon materials are co-optimised through a 'dual-function' strategy. Briefly, K3Fe(C2O4)3 and H3BO3 were hybridised with a gelatin aqueous solution to form a homogeneous composite hydrogel, followed by lyophilisation and carbonisation. Owing to the dual functionality of raw materials, the graphitization, activation and hetero-atom doping processes can occur simultaneously during a one-step high-temperature treatment. The resultant carbon material exhibits a high graphitization degree (ID/IG = 0.9 ± 0.1), high hetero-atom content (N: 9.0 ± 0.3 at.%, B: 6.9 ± 0.5 at.%) and a large specific area (1754 ± 58 m2/g). The as-prepared electrode demonstrates a superior capacitance of 383 ± 1F g-1 at 1 A/g. Interestingly, the cyclic voltammetry (CV) curves exhibit a distinctive pair of broad redox peaks, which is uncommon in KOH electrolyte. Experiment data and density functional theory (DFT) simulation verify that N-5, B co-doping enhances the activity of the faradic reaction of carbon electrodes in KOH electrolyte. Furthermore, the fabricated Zn-ion hybrid supercapacitor (ZHSC) based on this carbon electrode delivers a high-energy density of 140.7 W h kg-1 at a power density of 840 W kg-1.

Preoxidation and Prilling Combined with Doping Strategy to Build High-Performance Recycling Spent LiFePO4 Materials.

Direct regeneration has gained much attention in LiFePO4 battery recycling due to its simplicity, ecofriendliness, and cost savings. However, the excess carbon residues from binder decomposition, conductive carbon, and coated carbon in spent LiFePO4 impair electrochemical performance of direct regenerated LiFePO4. Herein, we report a preoxidation and prilling collaborative doping strategy to restore spent LiFePO4 by direct regeneration. The excess carbon is effectively removed by preoxidation. At the same time, prilling not only reduces the size of the primary particles and shortens the diffusion distance of Li+ but also improves the tap density of the regenerated materials. Besides, the Li+ transmission of the regenerated LiFePO4 is further improved by Ti4+ doping. Compared with commercial LiFePO4, it has excellent low-temperature performance. The collaborative strategy provides a new insight into regenerating high-performance spent LiFePO4.

Effect of calcium and phosphorus on ammonium and nitrate nitrogen adsorption onto iron (hydr)oxides surfaces: CD-MUSIC model and DFT computation.

Calcium (Ca2+) and phosphorous (PO43-) significantly influence the form and effectiveness of nitrogen (N), however, the precise mechanisms governing the adsorption of ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) are still lacking. This study employed batch adsorption experiments, charge distribution and multi-site complexation (CD-MUSIC) models and density functional theory (DFT) calculations to elucidate the mechanism by which Ca2+ and PO43- affect the adsorption of NH4+-N and NO3--N on the goethite (GT) surface. The results showed that the adsorption of NH4+-N on the GT exhibited an initial increase followed by a decrease as pH increased, peaking at a pH of 8.5. Conversely, the adsorption of NO3--N decreased with rising pH. According to the CD-MUSIC model, Ca2+ minimally affected the NH4+-N adsorption on the GT but enhanced NO3--N adsorption via electrostatic interaction, promoting the adsorption of ≡FeOH-NO3- and ≡Fe3O-NO3- species. Similarly, PO43- inhibited the adsorption of ≡FeOH-NO3- and ≡Fe3O-NO3- species. However, PO43- boosted NH4+-N adsorption by facilitating the formation of ≡Fe3O-NH4+ via electrostatic interaction and site competition. DFT calculations indicates that although bidentate phosphate (BP) was beneficial to stabilize NH4+-N than monodentate phosphate (SP), SP-NH4+ was the main adsorption configuration at pH 5.5-9.5 owing the prevalence of SP on the GT surface under site competition of NH4+-N. The results of CD-MUSIC model and DFT calculation were verified mutually, and provide novel insights into the mechanisms underlying N fixation and migration in soil.

Anti-Coronavirus Potential of Polyether Ionophores: The New Application of Veterinary Antibiotics in Livestock.

Coronaviruses have consistently posed a major global concern in the field of livestock industry and public health. However, there is currently a lack of efficient drugs with broad-spectrum antiviral activity to address the challenges presented by emerging mutated strains or drug resistance. Additionally, the method for identifying multitarget drugs is also insufficient. Aminopeptidase N (APN) and 3C-like proteinase (3CLpro) represent promising targets for host-directed and virus-directed strategies, respectively, in the development of effective drugs against various coronaviruses. In this study, maduramycin ammonium demonstrated a broad-spectrum antiviral effect by targeting both of the proteins. The binding domains 4 Å from the ligand of both target proteins shared a structural similarity, suggesting that screening and designing drugs based on these domains might exhibit broad-spectrum and highly effective antiviral activity. Furthermore, it was identified that the polyether ionophores' ability to carry zinc ion might be one of the reasons why they were able to target APN and exhibit antiviral effect. The findings of this experiment provide novel perspectives for future drug screening and design, while also offering valuable references for the utilization of polyether ionophores in the management of livestock health.