Strong Stability Research Articles

Effects of Laurus extract against cadmium-induced neurotoxicity in rats

Cadmium (Cd) is a hazardous heavy metal with widespread environmental presence, posing significant threats to human and animal health. This study investigates the neurotoxic effects of Cd exposure and explores the therapeutic efficacy of Laurus nobilis L. in counteracting these adverse effects. Cd exposure induces oxidative stress and neurotoxicity, leading to neuronal damage and histopathological alterations. Laurus, known for its antioxidant properties, is assessed for its potential in mitigating Cd-induced neurotoxicity through in vitro antioxidant assays, GC–MS analysis, HPLC profiling, and experimental animal models. Results demonstrate that Laurus ethanolic extract exhibits significant antioxidant activity, attributed to its phenolic and flavonoid constituents. GC–MS analysis reveals various bioactive compounds in the extract, including Hexadecanoic acid methyl ester and (Z)-13-Docosenamide, which posses neuroprotective properties. HPLC analysis identifies phenolic compounds such as ellagic acid and flavonoids like rutin and kaempferol in the extract. In vivo studies in rats exposed to Cd demonstrate that Laurus extract administration mitigates Cd-induced alterations in body and brain weight, hematological parameters, liver and kidney function, oxidative stress markers, and acetylcholinesterase (AchE) activity. Histopathological examination confirms the protective effects of Laurus against Cd-induced neuronal damage. The SOD model, validated with high resolution (2.05 Å) and strong R values (work: 0.192, free: 0.236, observed: 0.194), shows strong structural stability (C-score: 0.30). Docking studies reveal high binding affinities of kaempferol (−8.1 kcal/mol) and rutin (−8.7 kcal/mol) with SOD with kaempferol demonstrating superior solubility, lipophilicity, and drug-likenessSimulation analysis confirms the protein’s flexibility and adaptability, highlighting its therapeutic potential, especially with kaempferol. These findings suggest the therapeutic potential of Laurus. as a natural remedy for Cd-induced neurotoxicity, highlighting its antioxidant and neuroprotective properties.

Discovery of novel and highly potent dual-targeting PKMYT1/HDAC2 inhibitors for hepatocellular carcinoma through structure-based virtual screening and biological evaluation

Simultaneous inhibition of two or more pathways is playing a crucial role in the treatment of hepatocellular carcinoma with complex and diverse pathogenesis. However, there have been no reports of dual-targeting inhibitors for protein kinase membrane-associated tyrosine/threonine 1 (PKMYT1) and histone deacetylase 2 (HDAC2), which are critical targets for hepatocellular carcinoma treatment. Here, an integrated strategy of virtual screening was utilized to identify dual-targeting inhibitors for PKMYT1 and HDAC2. Notably, PKHD-5 has been identified as a potent inhibitor that selectively targets both PKMYT1 and HDAC2 with nanomolar affinity. Molecular dynamics have confirmed the strong binding stability of PKHD-5 with PKMYT1 and HDAC2. Importantly, it displayed a notably lower IC50 against the HepG2/MDR cell line, underscoring its potential to surmount drug resistance, while exhibiting minimal toxicity towards the normal liver cell line L02. Additionally, PKHD-5 has demonstrated significant antitumor proliferation effects without significant toxicity. In summary, the results suggest that PKHD-5 is a promising candidate for further preclinical studies of hepatocellular carcinoma therapy.

Integrated virtual screening and MD simulation study to discover potential inhibitors of mycobacterial electron transfer flavoprotein oxidoreductase.

Tuberculosis (TB) continues to be a major global health burden, with high incidence and mortality rates, compounded by the emergence and spread of drug-resistant strains. The limitations of current TB medications and the urgent need for new drugs targeting drug-resistant strains, particularly multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB, underscore the pressing demand for innovative anti-TB drugs that can shorten treatment duration. This has led to a focus on targeting energy metabolism of Mycobacterium tuberculosis (Mtb) as a promising approach for drug discovery. This study focused on repurposing drugs against the crucial mycobacterial protein, electron transfer flavoprotein oxidoreductase (EtfD), integral to utilizing fatty acids and cholesterol as a carbon source during infection. The research adopted an integrative approach, starting with virtual screening of approved drugs from the ZINC20 database against EtfD, followed by molecular docking, and concluding with molecular dynamics (MD) simulations. Diacerein, levonadifloxacin, and gatifloxacin were identified as promising candidates for repurposing against TB based on their strong binding affinity, stability, and interactions with EtfD. ADMET analysis and anti-TB sensitivity predictions assessed their pharmacokinetic and therapeutic potential. Diacerein and levonadifloxacin, previously unexplored in anti-tuberculous therapy, along with gatifloxacin, known for its efficacy in drug-resistant TB, have broad-spectrum antimicrobial properties and favorable pharmacokinetic profiles, suggesting potential as alternatives to current TB treatments, especially against resistant strains. This study underscores the efficacy of computational drug repurposing, highlighting bacterial energy metabolism and lipid catabolism as fruitful targets. Further research is necessary to validate the clinical suitability and efficacy of diacerein, levonadifloxacin, and gatifloxacin, potentially enhancing the arsenal against global TB.

Self-Healing, Electrically Conductive, Antibacterial, and Adhesive Eutectogel Containing Polymerizable Deep Eutectic Solvent for Human Motion Sensing and Wound Healing.

Flexible electronic devices such as wearable sensors are essential to advance human-machine interactions. Conductive eutectogels are promising for wearable sensors, despite their challenges in self-healing and adhesion properties. This study introduces a multifunctional eutectogel based on a novel polymerizable deep eutectic solvent (PDES) prepared by the incorporation of diallyldimethylammonium chloride (DADMAC) and glycerol in the presence of polycyclodextrin (PCD)/dopamine-grafted gelatin (Gel-DOP)/oxidized sodium alginate (OSA). The synthesized eutectogel has reversible Schiff-base bonds, hydrogen bonds, and host-guest interactions, which enable rapid self-healing upon network disruption. GPDO-15 eutectogel has significant tissue adhesion, high stretchability (419%), good ionic conductivity (0.79 mS·cm-1), and favorable antibacterial and self-healing properties. These eutectogels achieve 90% antibacterial effect, show excellent biocompatibility, and can be used as sensors to monitor human activities with strong stability and durability. The in vivo studies indicate that the eutectogels can improve the wound healing process which makes them an effective option for biological dressings.

Numerical simulation of three-dimensional seepage field in a tailing pond under multiple operating conditions.

Establishing strong seepage stability for tailings dams is crucial for ensuring their safety and mitigating the risk of failure. This study developed a three-dimensional seepage numerical model using finite element numerical computation for four different elevation conditions (5070m, 5081m, 5159m, and 5213m) encompassing the pond area and dam body. Seepage calculations were conducted under normal and flooding conditions, and the tailings pond's seepage stability was assessed for various stacking scenarios. The spatial distribution pattern of the infiltration surface and the hydraulic stability of the tailings pond were evaluated, which provides insights into the three-dimensional infiltration stability. Examining the seepage stability under different accumulation conditions revealed distinct spatial distribution patterns of the infiltration surface and hydraulic ratio drop values. The findings indicated that the maximum permeability slope at 5070m elevation ranged from 0.66 to 0.75 at normal operation water level and maximum flood level. Most hydraulic ratio drop values at 5081m were below 0.2, while the anti-seepage lining sections at 5159m and 5213m showed larger values, and maintained the overall hydraulic ratio drop within safe limits. Consequently, the dam body's permeability was deemed secure, and no infiltration damage was anticipated with the proposed design of seepage control and drainage facilities. Moreover, sensitivity analysis of the tailing sand's permeability coefficient demonstrated that variations between 0.2 and 5 times the given parameter align with the seepage control requirements for the tailings dam. Additionally, local geomembrane breakage was found to have minimal impact on the tailing pond's seepage field and the dam body's permeability stability, which provides a scientific foundation for analyzing and designing the seismic static-dynamic stability of the tailings pond.

Point‐of‐care testing of DNA damage markers‐8‐hydroxy‐2′‐deoxyguanosine based on cobalt‐iron‐platinum‐ruthenium/N doped ordered mesoporous carbon

AbstractIn this work, we achieved point of care detection of DNA damage marker 8‐hydroxy‐2’‐deoxyguanosine (8‐OH‐dG) on tetrapartite metal nanoparticles loaded ordered mesoporous carbon composite nanomaterials (Co‐Fex‐Pt−Pd@NOMC). Nitrogen doping and co‐metal loading were achieved using dopamine as nitrogen, carbon sources and metal linker. In addition, the presence of catechol groups in dopamine with strong affinity for metal ions, make the simultaneous confinement of metals inside and outside the pores of ordered mesoporous carbon. Then, Fe, Pt and Pd metal nanoparticles were introduced to interact with Co nanoparticles to form four‐in‐one alloy nanoparticles by oil bath and carbonisation. The finally formed Co−Fe6‐Pt−Pd@NOMC nanocomposites exhibited excellent catalytic performance for the determination of 8‐OH‐dG. A lower limit of detection (LOD) of 0.044 μM, a wide linear range (0.175 μM–118.375 μM) and strong stability, reproducibility and selectivity were obtained. In addition, Co−Fe6‐Pt−Pd@NOMC realised the detection of 8‐OH‐dG in real human urine sample. At the same time, 8‐OH‐dG after DNA damage and guanine damage were also studied in this work. The electrochemical response of 8‐OH‐dG was combined with DNA damage to verify the mechanism of DNA damage. New solutions and idea were provided for the preparation of inorganic nanocomposites for the detection of 8‐OH‐dG in this work.

Temperature stability analysis of the all-fiber current sensor with a loop structure

Abstract All-fiber optical current sensor (AFOCS) is a perfect product formed by the combination of fiber-optic sensing technology and the Faraday effect. It boasts significant advantages such as resistance to electromagnetic interference, a high measurement dynamic range and precision, low power consumption, low cost, and insulation. Additionally, it enables long-distance transmission, making it one of the main devices for current monitoring in smart grids. However, the birefringence within the sensing fiber is highly susceptible to changes in temperature, causing the polarization state of light to be extremely sensitive to temperature variations. This sensitivity significantly impacts the accuracy of current measurements. A novel loop structure AFOCS with a coupled fiber polarization rotator (FPR) is introduced in this paper. The operating principle of this structure is theoretically analyzed, and the Jones matrix is used to analyze the output light intensity signal and derive the error formula. After comparing the measurement accuracy of the basic AFOCS and the loop structure AFOCS, it is demonstrated that this novel structure can improve current sensitivity by enhancing the temperature robustness of the system. Additionally, the error generated by the FPR is controlled below 1%, meeting the requirements for stable system operation. Therefore, this novel structure effectively improves the accuracy of current measurement and exhibits strong temperature stability.

Structural Characteristics of Expressway Carbon Emission Correlation Network and Its Influencing Factors: A Case Study in Guangdong Province

Understanding the spatial correlation of transportation carbon emissions and their influencing factors is significant in achieving an overall regional carbon emission reduction. This study analyzed the structure characteristics of the expressway carbon emission correlation network in Guangdong Province and examined its influencing factors with intercity expressway traffic flow data using social network analysis (SNA). The findings indicate that the correlation network of expressway carbon emissions in Guangdong Province exhibited a “core-edge” spatial pattern. The overall network demonstrated strong cohesion and stability, and a significant difference existed between the passenger vehicle and freight vehicle carbon emission networks. The positions and roles of different cities varied within the carbon emission network, with the Pearl River Delta (PRD) cities being in a dominant position in the carbon network. Cities such as Guangzhou, Foshan, and Dongguan play the role of “bridges” in the carbon network. The expansion of differences in GDP per capita, industrial structure, technological level, and transportation intensity facilitates the formation of a carbon emission network. At the same time, geographical distance between cities and policy factors inhibit them. This study provides references for developing regional collaborative carbon emission governance programs.

EXTH-71. A MECHANISTIC INVESTIGATION INTO AUGER THERAPY: 2-DIMENSIONAL THIN-FILMS TO CHARACTERIZE THERAPEUTIC RANGEIN VITRO

Abstract Metallic nanoparticles can improve the accuracy and effectiveness of conventional radiotherapy in the treatment of solid tumors through a light-matter interaction known as the Auger effect. In this work, we present the assembly of an iron oxide (Fe3O4) nanoparticle (NPs) layer within a biocompatible polyelectrolyte film using ionic self-assembly to enable the spatial separation of NPs from their target cells. Films exhibited uniform nanoparticle coverage as well as strong stability in cell culture conditions. To investigate the applicability of NMDR with non-internalized NPs, conditions with (NP-PEM) and without (PEM) embedded nanoparticles were used to evaluate the therapeutic effect of physically separated nanoparticles on cells cultured on the film surface via a measure of intracellular reactive oxygen (ROS) generation and histone phosphorylation (yH2AX) after irradiation from a 137Cesium source. Cells cultured on NP-PEM demonstrated a 78.4% increase in ROS generation when compared to cells cultured on PEM films. When adjusting for cell count, NP-PEM films induce 70.5% greater ROS generation. In investigating nanoparticle-mediated deposition of radiation (NMDR), these films allow for the determination of the extent of the therapeutic effect when NPs are not internalized into their targeted cells, potentially providing indications with respect to off-target effects. Cells were irradiated on films with nanoparticle distances from 25.9 nm to 97.5 nm to interrogate the NMDR effect size at a range of distances. yH2AX phosphorylation exhibited an exponential decay until 69.8 nm, where there was no difference when compared to nanoparticle-free films. This work highlights the ability of iron oxide NPs to deliver NMDR at a known, quantifiable distance, providing insights for further translational applications.

Molecular hybridization modification improves the stability and immunomodulatory activity of TP5 peptide

Thymopentin (TP5) plays an important role in host immunomodulation, yet its bioavailability is significantly limited by its short half-life. YW12D is a peptide with strong stability but relatively weak immunoactivity. Tuning the physicochemical properties of such molecules may yield synthetic molecules displaying optimal stability, safety and enhanced immunological activity. Here, natural peptides were modified to improve their activity by hybridization strategies. A hybrid peptide YW12D-TP5 (YTP) that combines TP5 and YW12D is designed. The half-life of YTP in plasma is significantly longer than that of YW12D and TP5. YTP also displays an improved ability to protect the host from CTX-induced weight loss and thymus and spleen indices decrease than YW12D and TP5. In addition, YTP promotes dendritic cell maturation and increases the expression of cytokines IL-1β, IL-6, TNF-α and immunoglobulins IgA, IgG, and IgM. A combination of antibody-specific blocking assay, SPR, molecular dynamics simulations and western blotting suggest that the immunomodulatory effect of YTP is associated with its activation of the TLR2-NF-кB signaling axis. In sum, we demonstrate that peptide hybridization is an effective strategy for redirecting biological activity to generate novel bioactive molecules with desired properties.

Fabrication of High-Performance Neural Stimulation Electrode through Pulsed Electrochemical Deposition of IrOx onto Nano-Porous Platinum

Abstract Electrodes for neural stimulation are pivotal in medical and brain science applications. This study aims to prepare novel neural stimulating electrodes with enhanced electrochemical performance and improved mechanical stability through a two-step electrochemical deposition process. Initially, a highly porous platinum (Porous-Pt) electrode with high nanoscale roughness is fabricated, followed by the incorporation of IrOx onto the Porous-Pt surface. The resulting IrOx/Porous-Pt electrode combines the advantages of both materials, offering low impedance, significantly increased CIC, and improved mechanical stability. Scanning electron microscopy revealed that the porous surface of the electrode consisting of sphere-shaped Pt nanoparticles offers a significant effective surface area, promoting strong adhesion and stability for uniform IrOx deposition onto Porous-Pt. This characteristic contributed to the long-term mechanical stability of the IrOx/Porous-Pt electrode.

Highly Efficient Flexible Antimony Halide Scintillator Films with In Situ Preparation for High‐Resolution X‐Ray Imaging

AbstractFlexible scintillators with high light yield, spatial resolution and low light scattering are ideal for X‐ray imaging application. However, conventional scintillators are always prepared by crystallization of functional layer, grinding and mixing with polymers, resulting in serious light scattering. Herein, an in situ fabrication strategy is proposed to prepare a low light scattering flexible scintillator film based on 0D antimony halide C38H36P2SbCl5 (MTP2SbCl5). The prepared scintillator film exhibits bright yellow emission with an outstanding photoluminescence quantum yield (PLQY) of 99.69%, and it demonstrates linear responsiveness to X‐ray dose, achieving an impressive light yield of 39800 photons MeV−1 and a low detection limitation of 78.4 nGyair s−1. The scintillator film possesses strong radiation hardness and stability. In addition, low light scattering greatly inhibits optical crosstalk during X‐ray detection, effectively improving the spatial resolution of MTP2SbCl5 film from 4.5 to 10.2 lp mm−1. On account of the simple preparation method and high performance, this work provides guidance for the preparation of high‐efficiency, large‐area, low‐scattering and high‐resolution flexible scintillator in the future.

CsPbBr3 perovskite quantum dots/p-GaN heterojunction for ultraviolet-visible spectrum photodetectors

All-inorganic perovskites have attracted increasing attention because of their strong environmental stability and excellent photoelectric properties. However, the limited spectral response range of perovskite photodetectors restricts them in practical applications. In this work, an ultraviolet–visible photodetector with a wide spectral response and a high responsivity was prepared by constructing a CsPbBr3 quantum dots (QDs)/p-GaN heterojunction. The type-II energy band alignment formed by the heterojunction is conducive to the transport of photogenerated carriers, resulting in a high responsivity. Under certain conditions, the device can obtain responsivity values of 5 A/W and 850 mA/W under 350 and 725 nm illumination, respectively, which are comparable to those of other perovskite-based photodetectors. In addition, the photoresponse mechanism of the device is revealed through first-principles calculations of the heterojunction and the device. The enhanced light absorption of the heterojunction and the special band bending under different bias voltages improve the photoelectric performance of the device. This work can provide valuable insights into high-performance photodetectors based on all-inorganic perovskite QDs heterojunctions in terms of band regulation and device performance improvement.

The Removal and Mitigation Effects of Biochar on Microplastics in Water and Soils: Application and Mechanism Analysis

Due to their widespread distribution, microplastics (MPs) are endangering the soil ecological environment system, causing water pollution and altering the soil’s physicochemical and microbiological features. Because of its unique pore structure and strong stability, biochar is widely used as an adsorbent. However, the effects of MP–biochar interactions in water and soil environment are still unclear. This review outlines the application and mechanism of biochar as an adsorbent in a water environment for the removal of MPs. Also, biochar serves as remediation material for MPs in soils as it mitigates the adverse effects of MPs on soil properties, enzyme activities and soil microbial community. It was found that woody biochar had the highest yield and was more effective in adsorbing MPs. Further research should focus on the combined effects of biochar and MPs, the environmental risks of biochar, the modification of biochar application of MP-removal technologies, the characterization of MP properties, the remediation of combined contamination of MPs and other pollutants, and the transportation of MPs.

One-step synthesis of fluorine-functionalized intercalated graphene with adjustable layer spacing for both enhanced physical and chemical hydrogen storage

Graphene-based materials with large specific surface area, strong stability and easy adjustability attract considerable attention in the field of hydrogen storage; however, they suffer from poor hydrogen adsorption ability as direct physical adsorbents or limited modification effect as catalytic supporters of chemical hydrides, blamed to tightly stacked layer structure and chemical inertness. Structural engineering and functional decoration on graphene have been proven to be effective strategies for enhancing both physical and chemical hydrogen storage performances, but there is still lack of simple and flexible method to achieve their synergy. Here for the first time, we develop a fluorine-functionalized intercalated graphene with adjustable layer spacing by one-step solvothermal process, using fluorinated organic molecules as both intercalation and function agents. By the virtue of expanded interlayer and high-electronegative fluorine, it shows polarization-enhanced physisorption ability. Moreover, when using it as the supporter for LiBH4, the operation temperature, reaction kinetics and cyclic stability of the whole system are greatly improved, attributed to the intrinsic catalysis of carbonaceous materials and the destabilization induced by fluorine substitution. This work provides new views for structural and functional co-design in graphene derivate, and brings hope for their practical application for hydrogen storage.

Firearm Availability Reduces the Stability of Suicidal Ideation: Results from an Ecological Momentary Assessment Study

Firearm availability is correlated with increased risk of suicide but its link with suicidal ideation remains unclear. Previous studies are limited by retrospective reports and prospective designs with lengthy gaps between assessments that are ill-suited for measuring fluctuations in suicidal ideation. This study used ecological momentary assessment (EMA) to repeatedly assess suicidal ideation in a sample of 138 U.S. adults (81 handgun owners, 57 non-owners). Participants received six EMA prompts per day for 28 consecutive days. Results revealed no group differences in the frequency, maximum amplitude, or variability of suicidal ideation across male and female handgun owners and non-owners. Stability of suicidal ideation significantly differed across groups, however (F(1,132) = 4.5, p = 0.036); male handgun owners had the strongest stability and male non-owners had the weakest stability. Stability of suicidal ideation was significantly lower when participants reported a firearm was nearby as compared to when no firearm was nearby (F(4,17732) = 5.6, p < 0.001). Results suggest firearm availability increases reactivity to the environment, slows recovery from acutely elevated risk states, and may increase vulnerability to sudden shifts to higher risk states characterized by increased probability of suicidal behavior. Although these effects were observed in both handgun owners and non-owners, they disproportionately impact handgun owners because they report being near firearms more often.

Theoretical and experimental investigation of BaY2(MoO4)4:xSm3+ phosphors

In this paper, the novel BaY2(MoO4)4:xSm3+ phosphors with strong red emission and high thermal stabilization were prepared by a conventional method of high temperature solid state reaction in air atmosphere. Morphology, phase purity, element distribution, UV–Vis–NIR diffuse reflectance spectroscopy (DRS), and luminescence properties were investigated in detail. The crystal structure of the BaY2(MoO4)4 host was refined with the aid of the Rietveld refinement method by the GSAS program. The electronic band structure and phonon dispersion were performed using plane-wave density functional theory (DFT). The prepared BaY2(MoO4)4:Sm3+ phosphor exhibits excellent red emission under near-ultraviolet excitation. Strong red emission intensity and high thermal stability suggest potential application in backlighting or phosphor-covered white light-emitting diodes (pc-LEDs).

Assessing temporal variability in durum wheat performance and stability through multi-trait mean performance selection in Mediterranean climate

Durum wheat, a staple crop in Italy, faces substantial challenges due to increasing droughts and rising temperatures. This study examines the grain yield, agronomic traits, and quality of 41 durum wheat varieties over ten growing seasons in Southern Italy, utilizing a randomized complete block design. Notably, most varieties were not repeated between trials and 45% of the data was missing. The results indicate that the interaction between genotype and environment (GEI) significantly impacted all traits. High temperatures, elevated vapor pressure deficit (VPD), and water deficits severely affected yield and quality during warm years, while cooler years with favorable water availability promoted better growth and higher yields. Broad-sense heritability (H²) was generally low, suggesting that environmental factors played a major role in the observed traits. However, some traits, such as grain yield, ears per square meter, plant height, bleached wheat, thousand-grain weight, and hectoliter weight exhibited moderate to high heritability of the mean genotype (h²mg), indicating their potential for effective selection in breeding programs. Correlation analyses revealed strong connections between certain traits, such as protein content, and gluten index as well as between grain yield, and spike per square meter. Using the Multi-Trait Mean Performance Selection (MTMPS) index, the study identified six top-performing varieties. Among these, Antalis (G4) and Core (G18) consistently demonstrated strong adaptability and stability across different environments, particularly in hotter, drier conditions. Furio Camillo (G31) also exhibited valuable traits. This study highlights the challenges and complexities of breeding durum wheat for improved yield and quality in the face of climate change.

A novel Lax–Wendroff type procedure of two-derivative time-stepping schemes for Euler and Navier–Stokes equations

In this paper, we developed a novel Lax–Wendroff (LW) type procedure of two-derivative time-stepping schemes for the Euler and Navier–Stokes equations. The explicit two-derivative time-stepping schemes, including the two-derivative Runge–Kutta schemes and variable step size two-derivative multistep schemes, are proposed and the optimized time-stepping schemes are determined by the strong stability preserving theory. The novel LW procedure greatly simplifies the intricate symbolic calculations of the original LW procedure, particularly for the Navier–Stokes equations. The novel LW procedure also ensures both the order accuracy and numerical stability compared to the original LW procedure. Moreover, we presented a simplified positivity-preserving limiter for LW procedure, enabling the temporal schemes to handle demanding computations. When employing high-order spatial methods, numerical tests highlighted that two-derivative time-stepping schemes utilizing the novel LW procedure effectively improve the stability and computational efficiency compared to the Runge–Kutta schemes.

Electrochemical Synthesis of Metasequoia-Like Reduced Graphene Oxide Coated Cobalt-Silver Catalyst for Stable and Efficient Electrocatalytic Nitrate Reduction to Ammonia.

Electrocatalytic nitrate (NO3 -) reduction to ammonia (NH3) is a green and efficient NH3synthesis technology. Metallic silver (Ag) is one of the well-known electrocatalysts for NO3 - reduction. However, under alkaline conditions, its poor water-splitting ability fails to provide sufficient protonic hydrogen required for NH3 synthesis, resulting in low NH3 selectivity. Additionally, metal catalysts are prone to leaching and oxidation during electrocatalysis, resulting in poor stability. Herein, cobalt (Co) into Ag (CoAg) catalyst is doped, which not only increases the NH3 selectivity by 34.4%, but also reduces the reduction potential by 0.1V. Meanwhile, reduced graphene oxide (rGO) as a protective "armor" is used to encapsulate the CoAg catalyst (rGO2.92@CoAg). The rGO2.92@CoAg catalyst shows excellent stability for over 300 hours (h) of continuous reaction. The Co and Ag contents in the rGO2.92@CoAg catalyst after continuous tests decreases by only 4.3% and 3.1%, respectively, which are much lower than those of the CoAg catalyst without the rGO (90.8%, 52.6%). Moreover, the rGO2.92@CoAg catalyst shows high Faradaic efficiency (99.3%) and NH3 yield rate (1.47mmol h-1 cm-2). Therefore, a high performance and strong stability rGO2.92@CoAg catalyst is obtained by Co doping and rGO coating, which provides theoretical basis for practical industrial application.