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Purpose: To investigate the biocompatibility of silver nanoparticle (AgNP)-doped Ti-6Al-4V surfaces by evaluating the viability and proliferation rate of human gingival fibroblasts (HGFs)--as the dominant cells of peri-implant soft tissues-- seeded on the modified surfaces. Materials and Methods: AgNPs (sizes 8 nm and 30 nm) were incorporated onto Ti-6Al-4V specimen surfaces via electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations of 100 ppm, 200 ppm, and 300 ppm. One control and six experimental groups were included in the study: (1) control (Ti-6Al- 4V), (2) 8 nm/100 ppm, (3) 8 nm/200 ppm, (4) 8 nm/300 ppm, (5) 30 nm/100 ppm, (6) 30 nm/200 ppm, and (7) 30 nm/300 ppm. HGF cell primary cultures were isolated from periodontally healthy donor patients and cultured in direct contact with the group specimens for 24 and 72 hours. The cytotoxicity of AgNP-doped Ti-6Al-4V specimens toward HGF was assessed by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and BrdU (5-bromo-2'-deoxyuridine) assay tests. Calcein AM and ethidium homodimer (EthD-1) fluorescent stains were used to determine the live and dead cells. The morphology and attachment properties of the HGFs were determined via scanning electron microscopy (SEM). Results: Energy dispersive x-ray (EDX) analysis confirmed the presence of AgNPs on the specimens. The MTT test revealed that AgNPs of both sizes and all concentrations presented a decreased cellular metabolic activity compared to the control discs. All concentrations of both sizes of AgNPs affected the cell proliferation rate compared to the control group, as revealed by the BrdU assay. Overall, cytotoxicity of the modified Ti-6Al-4V surfaces depended on cell exposure time. Observation via confocal microscopy confirmed the results of the MTT and BrdU assay tests. Specifically, most cells remained alive throughout the 72-hour culture period. SEM images revealed that adjacent cells form bonds with each other, creating confluent layers of conjugated cells. Conclusions: The findings of the present study indicate that Ti-6Al-4V surfaces modified with 8 nm and 30 nm AgNPs at concentrations of 100 ppm, 200 ppm, and 300 ppm do not produce any serious cytotoxicity toward HGFs. The initial arrest of the HGF proliferation rate recovered at 72 hours. These results on the antibacterial activity against common periodontal pathogens, in combination with the results found in a previous study by the same research group, suggest that AgNP-doped Ti-6Al-4V surfaces are potential candidates for use in implant abutments for preventing peri-implant diseases. [ABSTRACT FROM AUTHOR]

A set of ferrocenyl-functionalized perylenediimide (PDI) compounds and their 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) derivatives 1–5 were designed and synthesized using palladium-catalyzed Sonogashira cross-coupling, followed by a thermally activated [2 + 2] cycloaddition–retroelectrocyclization [CA–RE] reaction with a 1,1,2,2-tetracyanoethylene (TCNE) acceptor in good yields. The TCBD group works as an acceptor, whereas the ferrocenyl group acts as a donor at the central PDI core. The effects of varying the number of ferrocenyl and TCNE groups on the photophysical, thermal, electrochemical, and spectroelectrochemical properties were studied. The di-substituted PDI derivatives 3, 4, and 5 exhibit bathochromic shifts in the absorption spectra compared to 1 and 2, attributed to the extended π-conjugation. The electrochemical analysis of derivatives 2, 4, and 5 shows multiple reduction waves in the low potential region due to the presence of TCBD and perylenediimide acceptor units. Spectroelectrochemical studies were performed, showing that upon applying redox potentials, the absorption spectra shifted from the visible to the near-infrared (NIR) region. Computational calculations indicate that in the HOMO, the electron density is localized on the ferrocene unit, while in the LUMO, it is distributed over the PDI–TCBD unit, indicating a strong D–A interaction. [ABSTRACT FROM AUTHOR]

By the reaction of the binuclear cobalt-containing polyoxovanadate [Co2(H2O)2V10O30]6− with methanol, a tridecanuclear cobalt containing polyoxovanadate, [Co13(OH)6(OCH3)6V24O72]10− (Co13), was synthesized. Single crystals suitable for X-ray crystallographic analysis were obtained as trimethylphenylammonium salts. The tridecanuclear cobalt core exhibited a planar disk structure and 24 vertex-sharing VO4 units surrounded the edge of the disk. This is the largest VO4-based polyoxovanadate as far as we know. Compound Co13 was stable in the solution state. Electrochemical analysis showed the possibility of Co13 to act as an oxidation catalyst for alcohols. Compound Co13 acted as a catalyst for oxidation of several alcohols. After the reaction, the Co13 catalyst was retrieved by the addition of an excess amount of ethyl acetate and filtration. The structure of the catalyst was maintained and reused. The oxidation of not only aromatic but also aliphatic alcohols proceeded with Co13. Compound Co13 showed catalytic performance for the oxidation of secondary alcohols even in the presence of alkenic and primary alcoholic functions. [ABSTRACT FROM AUTHOR]

Biosecurity encompasses the health and safety of humans, animals, plants, and the environment. In this article, "biosecurity" is defined as encompassing the comprehensive aspects of human, animal, plant, and environmental safety. Reliable biosecurity testing technology is the key point for effectively assessing biosecurity risks and ensuring biosecurity. Therefore, it is crucial to develop excellent detection technologies to detect risk factors that can affect biosecurity. An electrochemical microfluidic biosensing platform integrates fluid control, target recognition, signal transduction, and output and incorporates the advantages of electrochemical analysis technology and microfluidic technology. Thus, an electrochemical microfluidic biosensing platform, characterized by exceptional analytical sensitivity, portability, rapid analysis speed, low reagent consumption, and low risk of contamination, shows considerable promise for biosecurity detection compared to traditional, more complex, and time-consuming detection technologies. This review provides a concise introduction to electrochemical microfluidic biosensors and biosecurity. It highlights recent research advances in utilizing electrochemical microfluidic biosensing platforms to assess biosecurity risk factors. It includes the use of electrochemical microfluidic biosensors for the detection of risk factors directly endangering biosecurity (direct application: namely, risk factors directly endangering the health of human, animals, and plants) and for the detection of risk factors indirectly endangering biosecurity (indirect application: namely, risk factors endangering the safety of food and the environment). Finally, we outline the current challenges and future perspectives of electrochemical microfluidic biosensing platforms. [ABSTRACT FROM AUTHOR]

This study reports ambient electrosynthesis of dimethyl carbonate with a palladium–gold catalyst. Material screening identifies a region of intermediate‐catalyst binding energy that facilitates interfacial electron and proton transfers for selective carbonylation, achieving a distinct maximum of 92% faradaic efficiency to dimethyl carbonate. Structural and electrochemical analyses suggest that the alloying of palladium and gold effectively modulates the CO* binding energy to the catalytic surface, in accord with subsequent computational studies. With an extended heterogeneous–homogeneous catalytic environment with a halide redox mediator, a remarkable partial current density of 52 mA cm−2 is observed for dimethyl carbonate for 100 h of continuous operation. [ABSTRACT FROM AUTHOR]

AbstractFolate receptors (FRs) are important biomarkers that can indicate the presence of various cancers. Sensitive and accurate detection of FRs is crucial for early cancer diagnosis and treatment. The current methods of FRs detection have high cost, potential cytotoxicity, and complex production by relying on metallic nanomaterials, or have low electrical conductivity and sensitivity such as biopolymers. To address these challenges, a new approach using conducting nanofibers (CNFs) as bioelectronic surface was developed. A composite of sodium alginate (SA), a bio-friendly polymer, poly-ethylene oxide (PEO), an antifouling polymer, and poly(3-hexylthiophene) (P3HT), a semi-conducting organic polymer nanofiber was synthesized, with folic acid conjugated to the CNFs as a biorecognition element to target (FRs). The electrochemical and electrical properties were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy in a solution containing both a redox marker and free redox species. The CNFs exhibit electroactivity in buffer solution without a redox marker, owing to the electronic properties of the P3HT of EIS readout. The obtained biosensor significantly improved sensitivity, enabling the detection of FRs with a limit of detection (LOD) of 0.12 pM in human plasma, the high sensitivity compared to all previous approaches and a 25-fold improvement compared to the sensor described in our previous study, with improved selectivity. Additionally, the results showed a good biocompatibility toward MCF-7 breast cancer cells, which opens the way for their use as theragnostic nanoprobes for cancer cells diagnosis and therapy. This study provided a simple, low cost and sensitive analytical approach for folate receptor detection. [ABSTRACT FROM AUTHOR]

Electrochemical analysis of U 60 nanoclusters (Li 40 K 20 [UO 2 (O 2)(OH)] 60 (H 2 O) 214) and their natural analog, the mineral studtite (UO 2)O 2 (H 2 O) 2 ·(H 2 O) 2 , was carried out using cyclic voltammetry with a powder microelectrode setup. Voltammetric analysis was supplemented by ab initio quantum mechanical modeling to understand the mechanism, thermodynamics, and structural changes during redox transition (with a semi-quantitative kinetics evaluation). This research aims to better understand the redox behavior and transport of dissolved and structural (incorporated) uranyl units in the environment. Further analysis is performed to determine if redox switching of actinyl ions in clusters can be performed while leaving the cluster intact or at what redox transition it disintegrates. Quantum-mechanical calculations were applied to approximate electrochemical peak potential shifts and add them to standard reduction potentials to more accurately assign peaks to specific redox transitions between different species. These peak potentials are calculated from oxidation state-dependent binding energies between different uranyl species either within or adsorbed to U 60. This theoretical approach incorporates extensive error cancellation and serves to predict electrochemical redox potentials and identify the reaction taking place. Voltammograms of U 60 in electrolyte solutions exhibit kinetically-inhibited coupled redox peaks assigned to the U(VI)/U(V) transition of cluster structural uranyl units at −0.34 V (vs. standard hydrogen electrode), indicative of U 60 reduction from UO 2 2+ to UO 2 +. The U(V)/U(IV) transition at −0.71 V is assigned to the subsequent U 60 reduction of UO 2 + to UO 2 0. A method of observing these transitions in situ using synchrotron x-ray absorption spectroscopy was explored. Voltammetry, modeling, and peak analysis indicate a kinetically-inhibited two-step, one-e- (per step) reduction of U 60 from U(VI) to U(V) to U(IV). Voltammetry and x-ray absorption spectroscopy measurements performed before and after exhaustive cycling and the highly stable nature of U 60 provide evidence that clusters typically do not break apart upon reduction. Voltammograms of U 60 collected in varied uranyl solutions are indicative of UO 2 2+ adsorption to the cluster surface and its subsequent reduction at +0.24 V (U(VI)/U(V)) and −0.05 V (U(V)/U(IV)). For uranyl solutions in electrolyte, the two-step, one-e- (per step) reduction of U 60 is superseded by uranyl adsorption from solution to the electrode surface with subsequent reduction via U(V) disproportionation. This study represents the sole electrochemical investigation of U 60 in the literature and only the second of any uranyl peroxide nanocluster. It is also one of the first to use quantum–mechanical approaches in combination with existing solution-based standard reduction potentials to calculate Pourbaix (E H -pH) diagrams for adsorbed and structural species. [ABSTRACT FROM AUTHOR]

An electrochemical aptasensor was established for the fast and sensitive determination of tetracycline based on the synergistic effect of MoS2-thionine nanocomposite and aptamer. The glassy carbon electrode was coated with MoS2 nanosheets of thionine to immobilize the tetracycline aptamer. In the absence of tetracycline, large quantities of thionin were loaded on the surface of the MoS2 nanosheet to serve as the electrochemical probe. After tetracycline was added to the surface of the electrode, an aptamer analyte complex was produced on the modified electrode. Through intercalation and electrostatic interactions, the complex was substantially adsorbed onto thionine, and the peak currents of the redox signal of thionine decreased. Therefore, the concentration of tetracycline was monitored by the change in signal intensity. Under optimized conditions, the developed electrochemical strategy with MoS2-thionine composite and aptamer exhibited an excellent linear detection range of 1.0 nM–1.0 μΜ and a low detection limit of 0.6 nM with suitable selectivity and stability. Therefore, the fabricated platform offers great potential for food safety, medical detection, and drug analysis. [ABSTRACT FROM AUTHOR]

Few-layer graphitic carbon nanoribbons (GCN) with rich defective sites were prepared by pyrolysis at 800 oC in N2 of in situ-chelated Fe-polyaniline complexes synthesized via one-pot homogeneous Fenton-like oxidative polymerization of an acidic aniline solution. A minimal amount of iron (0.47 wt%) made a pivotal role in the nanoribbon growth and graphitization of GCN, and deposited highly dispersed iron species on GCN without post-synthesis acid leaching, which greatly simplified the synthesis procedure of GCN with improved yield. GCN exhibited high activity and stability for catalytic degradation of organic pollutants with peroxymonosulfate (PMS) mainly via non-radical pathways. The influences of various operating parameters on the catalytic performance of GCN were investigated. Scavenging tests, spin-trapping electron paramagnetic resonance spectra, electrochemical analyses, and theoretical calculations unveiled that 1O2 was the main reactive oxygen species generated from synergistic activation of PMS on GCN while GCN-mediated electron transfer made a minor contribution to organic degradation. [ABSTRACT FROM AUTHOR]

The strategy of converting waste materials into new functional materials is a promising approach for energy-storage applications, particularly in the case of silver-impregnated activated carbon (SAC). SAC, which is typically derived from coconut shells, is primarily used for water purification in home-based filters due to its excellent antibacterial properties. However, the silver concentration is low, and it tends to leach out after a certain period, resulting in waste. To address this issue, SAC was used as a precursor for electrodes in supercapacitor applications. Additional surface treatments, such as heteroatom doping, are also being employed to improve the electrical conductivity and wettability of SAC. Nitrogen was introduced using urea as a precursor to enhance the properties of SAC. XRD analysis confirmed the structural analysis of activated carbon and nitrogen-activated carbon. Morphological analysis revealed the formation of micropores on the surface of the samples. FTIR analysis confirmed the presence of functional groups in the samples. Raman spectra showed the presence of defects after the introduction of nitrogen atoms into the carbon lattice, with higher relative Id/Ig compared to AC. Multipoint bet analysis was conducted, and the surface area of the sample was found to be approximately 815m2g−1, with pore sizes of 810m2g−1. Electrochemical analysis was carried out in both three- and two-electrode configurations. The specific capacitance of NAC in cyclic voltammetry and galvanostatic charge–discharge analysis was found to be higher than that of AC because the nitrogen atoms reduced the ionic charge transfer resistance between the electrode and electrolyte surface. Electrochemical impedance spectroscopy (EIS) was also conducted, confirming the solution resistance with 1.5Ohm. [ABSTRACT FROM AUTHOR]

Iron‐ and nitrogen‐doped carbon (Fe─N─C) catalysts have garnered attention owing to their high oxygen reduction reaction (ORR) activity, which is comparable to that of Pt/C catalysts. Among the various methods for designing Fe─N─C catalysts, the use of templates has been emphasized as a means to create hierarchical porous structures. This strategy has enabled the achievement of high ORR activity. In this study, we propose a method for manufacturing a catalyst with high ORR activity by maximizing the interactions between commercial silica templates and catalyst precursors. By manipulating the charge on the commercial silica surface and adjusting the pH of the dispersion, the catalyst fabricated through these methods exhibited superior ORR activity compared to Pt/C and recently reported nonprecious metal catalysts. Through diverse physicochemical and electrochemical analyses, we confirmed that this activity stems from the effectively generated hierarchical porous structure and the resulting high density of Fe─N active sites. This catalyst exhibited a kinetic current density of over 2.73 mA cm−2, which is more than double that of platinum and displayed a high ORR mass activity of 4.49 mA mg−1. This strategy holds significant potential for application in various carbon‐based materials, paving the way for the development of highly efficient electrochemical energy devices. [ABSTRACT FROM AUTHOR]

Intercalation and deintercalation are fundamental processes in battery electrodes that involve the reversible addition and extraction of carrier ions such as lithium (Li) and sodium (Na) into a host framework made of transition metal (TM) ions and ligands. Although TM–ligand interactions are known to primarily determine intercalation potentials, a comprehensive understanding of their interactions involving the carrier ions still remains elusive. This study investigates the complex interactions between carrier ions (Li and Na) and the ligand in Berlin green (BG, Fe3+[Fe3+(CN)6]) cathodes to elucidate their effects on intercalation potentials and phase evolution. Comprehensive X‐ray characterizations and electrochemical analyses reveal that the strong carrier ion–ligand interaction, influenced by the type and concentration of carrier ions, can modify the electronic structure of Fe ions and affect the intercalated structure of BG cathodes, thereby tuning the intercalation potentials. Specifically, the enhanced covalent interaction of the Na–CN units compared with that of the Li–CN units induces rhombohedral distortion in the fully sodiated state and increases the working potential of high‐spin Fe ions. The findings highlight the critical role of carrier ion–ligand interactions in tuning the electrochemical properties of battery electrodes for the design of advanced battery systems. [ABSTRACT FROM AUTHOR]

This study introduces a rheological equivalent circuit model inspired by electrochemical impedance spectroscopy (EIS) to analyze complex viscosity data. By exploiting the similarity between the Cole–Cole plot in rheology and the Nyquist plot in EIS, the study adopts circuit fitting methodologies to interpret rheological behavior of various polymers. The model employs redefined electrochemical elements, including dashpots, springs, rheological constant phase elements, and Warburg elements, to capture both linear and non‐linear responses. This approach offers both analytical and predictive capabilities, providing new insights into material composition. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrite reduction (eNO2RR) is a promising alternative route to produce ammonia (NH3). Until now, several molecular catalysts have shown capability to homogeneously reduce nitrite to NH3, while taking advantage of added secondary‐sphere functionalities to direct catalytic performance. Yet, realizing such control over heterogeneous electrocatalytic surfaces remains a challenge. Herein, we demonstrate that heterogenization of a Fe‐porphyrin molecular catalyst within a 2D Metal–Organic Framework (MOF), allows efficient eNO2RR to NH3. On top of that, installation of pendant proton relaying moieties proximal to the catalytic site, resulted in significant improvement in catalytic activity and selectivity. Notably, systematic manipulation of NH3 faradaic efficiency (up to 90 %) and partial current (5‐fold increase) was achieved by varying the proton relay‐to‐catalyst molar ratio. Electrochemical and spectroscopic analysis show that the proton relays simultaneously aid in generating and stabilizing of reactive Fe‐bound NO intermediate. Thus, this concept offers new molecular tools to tune heterogeneous electrocatalytic systems. [ABSTRACT FROM AUTHOR]

The growing demand for energy storage has drawn considerable attention to devices such as supercapacitors, which currently lack high energy density but depict high power density and long cycle life. In this work, we have synthesized La0.3Sr0.7Ti0.5Fe0.5O3 (LSTF) nanoparticles and Ti3C2‐MXene‐modified LSTF nanoparticle hybrid to study the effect of MXene on electrochemical properties of the nanoparticles. The X‐ray diffraction (XRD) and Raman spectroscopy analysis showed that the hybrid structure retained all the major peaks of the nanoparticles and the MXene, which showed its successful synthesis. The morphological analysis was done utilizing scanning electron microscopy (SEM), which verified that the nanoparticles had been adsorbed and/or agglomerated onto the MXene sheets. The electrochemical analysis showed that with the addition of MXene into the nanoparticles, the specific capacitance tested via cyclic voltammetry increased from 225.6 Fg‒1 to 419.5 Fg‒1 at the scan rate of 2 mVs-1, which makes the hybrid a suitable electrode material for supercapacitors. The value of specific capacitance for the hybrid tested via galvanostatic charge‐discharge showed an increased value of 23 Fg‒1 at the current density of 1 Ag-1. The Fourier transform infrared (FTIR) spectroscopy showed that the hybrid contains –O functional groups coming from MXene, which causes an increase in electrochemical activity at the electrode surface, resulting in enhanced capacitance. [ABSTRACT FROM AUTHOR]

This work explores polyanionic phosphate-type α-Zn3(PO4)2 (ZP) as a negative electrode in lithium-ion batteries. It has a high theoretical capacity of 278 mA h g−1. The crystal structure of ZP is elucidated, and Patterson's electron density profiling is performed to understand the possible site of lithiation. To address the polaron-driven electrical insulation common to phosphates, we use superficial carbon coating (ZP/C). Furthermore, the electrochemical analysis of ZP and ZP/C is performed to validate the half-cell performance and Li+ kinetics. ZP/C delivers a high capacity of 260 mA h g−1 at 0.1 C. The positive effect of carbon coating is evident from a 100-fold increase in lithium diffusion coefficient from the galvanostatic intermittent titration technique. In addition, temperature-driven capacity performance is analyzed at −10, 25, and 50 °C. Temperature gradient charge–discharge is performed between −10 and −5 °C, where the discharge capacity increases from 70 to 100 mA h g−1 at 1 C rate, extending the application toward low-temperature non-carbonaceous energy storage solutions. [ABSTRACT FROM AUTHOR]

ABSTRACT Amid growing environmental concerns and the need for a sustainable future, green synthetic methodologies are gaining popularity for their simplicity and nontoxicity. In pursuit of the eco‐friendly synthesis of nanomaterials, the study reports an innovative synthesis of Ag‐CuO nanocomposites via the coprecipitation method utilizing Citrus limetta fruit juice extract as the bioreductant and stabilizing agent. The morphological and structural characteristics of the fabricated nanocomposites were evaluated by ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM), X‐ray diffraction (XRD), Raman and Brunauer–Emmett–Teller (BET) analyses. The nanocomposites were crystalline with particle sizes ranging from 15 to 24 nm and exhibited spherical and rod‐like shapes. The band gap value and specific surface area of the nanocomposites were found to be 1.5 eV and 25.50 m2/g, respectively. The photoluminescence (PL) analysis and electrochemical studies revealed significant charge separation and effective charge migration behaviour of the nanocomposites, respectively. The nanocomposites effectively catalysed the synthesis of Schiff bases from aryl aldehydes and aromatic amines at room temperature and without solvents. The reactions proceeded in a brief time with excellent product yields, and the nanocatalyst retained its activity for five consecutive cycles. The nanocomposites also efficiently catalysed the photodegradation of Congo red dye under visible light. A significant degradation of 94.33% was attained in 55 min, and the nanocatalyst maintained its efficacy over four consecutive reaction cycles. Moreover, the nanocomposites exhibited notable anticancer properties against the MCF‐7 (human breast) cell line, demonstrating a remarkable cytotoxicity rate of 87.79%. The findings highlight the efficacy of the biosynthesized nanocomposites in catalysis, environmental remediation and biological applications. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is a critical step for oxygen production during the electrochemical splitting of water. Effective OER catalysts support the development of clean energy technologies by increasing the energy efficiency of these processes. In this study, carbon aerogel (CA) was first synthesized as a catalyst support material using sol-gel, supercritical drying, and pyrolysis process. Then, mono-metallic (Pd/CA, Al/CA), bi-metallic (Pd–Al/CA, Pd–Ni/CA), and tri-metallic (Pd–Ni–Al/CA) catalysts were synthesized by microwave irradiation method. Inductively coupled plasma-mass spectrometry (ICP-MS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy have been made to examine the structural properties of the synthesized catalysts. Electrochemical analysis was carried out through cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS) in alkaline media (1 M KOH: Methanol) to examine the effect of metal loading of CA support material towards OER performance. All the compositions showed excellent activity toward OER, among all Pd–Ni/CA catalysts showed the highest activity. The OER peak current increased remarkably up to 48 mA cm−2 with methanol addition, which signifies the substantial application of carbon aerogel supported-Pd-Ni-Al catalysts in direct methanol fuel cells (DMFCs). Pd–Ni/CA display high OER performance with maximum diffusion coefficient, Do (6.6 × 10−8 cm2 s−1) and heterogeneous rate constant, ko (4.706 × 10−4 cm s−1), and smaller value of Tafel slope (128 mV dec−1). Electrochemical studies predicted that all the prepared carbon aerogel supported-Pd-Ni-Al catalysts can be used as efficient catalysts for OER and other related electrocatalysis applications. • Carbon aerogel (CA) supported Pd–Ni–Al based catalysts were synthesized. • Microwave irradiation method was used as catalyst preparation method. • Mono-metallic (Pd/CA, Al/CA), bi-metallic (Pd–Al/CA, Pd–Ni/CA) and tri-metallic (Pd–Ni–Al/CA) catalysts were synthesized. • Carbon aerogel supported Pd–Ni–Al catalysts can be used as efficient catalyst for OER. [ABSTRACT FROM AUTHOR]

Zirconium-based alloys are highly regarded by the research community for their exceptional corrosion resistance, thermal stability, and mechanical properties. In our work, we investigated two newly developed alloys, Zr42.42Cu41.18Al9.35Ag7.05 and Zr46.81Cu35.44Al10.09Ag7.66, in the form of ingots and ribbons. In the course of our investigation, we conducted a comprehensive structural and thermal analysis. In addition, an examination of the corrosion activity encompassing electrochemical studies and an analysis of the corrosion mechanisms was carried out. To further evaluate the performance of the materials, tests of their mechanical properties were performed, including microhardness and resistance to abrasive wear. Structural analysis showed that both alloys studied had a multiphase, crystalline structure with intermetallic phases. The samples in the form of ribbons showed improved corrosion resistance compared to that of the ingots. The ingot containing a higher content of copper Zr42.42Cu41.18Al9.35Ag7.05 was characterized by better corrosion resistance, while showing lower average hardness and a higher degree of abrasive wear based on SEM observations after pin-on-disc tests. [ABSTRACT FROM AUTHOR]

• The organic-inorganic hybrid coating forms an interpenetrating network structure. • The "labyrinth effect" of the organic-inorganic hybrid coating preventing the transmission and diffusion of corrosive media. • Multifunctional performances owing to the unique physical barrier and friendly interfacial interaction. • Bronze anticorrosion mechanism was investigated through electrochemical analysis. Bronze relics with vital historical, artistic, and scientific value, are one of the significant symbolizations of human civilization. However, due to the long burial time and the change in storage conditions, an inevitable and thorny problem arises in preventing the ancient bronze relics from corrosion. Coatings have great potential for metal corrosion protection at present. This study prepared a multifunctional coating consisting of zinc oxide (ZnO), titanium dioxide (TiO 2), and fluoroethylene vinyl ether (FEVE) polymer by an organic-inorganic hybrid, which was applied onto the surface of corroded bronze using a self-assembly method and spraying. The rough structure of composite coating resembling that of the mastoid structure found on lotus leaf, effectively prolongs the transmission path of corrosive ions while preventing bronze contact with the corrosive media. Additionally, this study mainly investigated the bronze anti-corrosion mechanism through an electrochemical analysis perspective. Electrochemical tests revealed the lower corrosion current density, and the positive corrosion potential of multifunctional FEVE@ZnO/TiO 2 coating immersion in 3.5 wt% NaCl solution. The experimental results demonstrate that the synergistic effect of organic-inorganic significantly enhances corrosion resistance by retarding the corrosion process and providing active protection against corrosion. The multifunctional coating also exhibits exceptional self-cleaning properties and weatherability when without changing the bronze color and appearance. Consequently, this preparation strategy and research approach for constructing a multifunction coating has a great application prospect in the conservation of bronze relics and metal anti-corrosion. [ABSTRACT FROM AUTHOR]

Nucleic acids, like DNA and RNA, serve as versatile recognition elements in electrochemical biosensors, demonstrating notable efficacy in detecting various cancer biomarkers with high sensitivity and selectivity. These biosensors offer advantages such as cost-effectiveness, rapid response, ease of operation, and minimal sample preparation. This review provides a comprehensive overview of recent developments in nucleic acid-based electrochemical biosensors for cancer diagnosis, comparing them with antibody-based counterparts. Specific examples targeting key cancer biomarkers, including prostate-specific antigen, microRNA-21, and carcinoembryonic antigen, are highlighted. The discussion delves into challenges and limitations, encompassing stability, reproducibility, interference, and standardization issues. The review suggests future research directions, exploring new nucleic acid recognition elements, innovative transducer materials and designs, novel signal amplification strategies, and integration with microfluidic devices or portable instruments. Evaluating these biosensors in clinical settings using actual samples from cancer patients or healthy donors is emphasized. These sensors are sensitive and specific at detecting non-communicable and communicable disease biomarkers. DNA and RNA's self-assembly, programmability, catalytic activity, and dynamic behavior enable adaptable sensing platforms. They can increase biosensor biocompatibility, stability, signal transduction, and amplification with nanomaterials. In conclusion, nucleic acids-based electrochemical biosensors hold significant potential to enhance cancer detection and treatment through early and accurate diagnosis. [ABSTRACT FROM AUTHOR]

We present an approach on the electrodeposition of gold nanoparticles (AuNPs) on a carbon fiber microelectrode (CFME) followed by deposition of nickel(II) tetrasulfonated phthalocyanine (p-NiTSPc) film by electropolymerization to form CFME-AuNPs/p-NiTSPc, for the sensitive determination of butylhydroxyanisole (BHA) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the topography, morphology, and elemental composition of CFME, CFME-AuNPs, CFME-p-NiTSPc, and CFME-AuNPs/p-NiTSPc, respectively. Additionally, the electrochemical impedance spectroscopy (EIS) technique was employed to evaluate the charge-transfer rate of the tested sensors. To establish the optimal conditions for the electroanalysis of BHA, various parameters were investigated, including the potential scan rate, pH, and electrolysis potential. CFME-AuNPs/p-NiTSPc demonstrated the highest BHA signal, corresponding to the highest active surface area of 0.025 cm2, compared to CFME-p-NiTSPc (0.024 cm2), CFME-AuNPs (0.022 cm2), and CFME (0.021 cm2). In a phosphate buffer solution (PBS, 0.1 M; pH 3), a good linear relationship (R2 = 0.998) was observed between peak current intensities and BHA concentrations in the range of 10–80 µM, resulting to a detection limit (LOD) of 3.60 µM (S/N = 3) and a quantification limit (LOQ) of 12 µM (S/N = 10). The analytical HPLC technique was also tested for BHA determination within the concentration range of 5.55–55.48 µM and the obtained LOD was calculated to be 4.41 µM. The potential interference of certain species that could affect the BHA oxidation signal was also evaluated, followed by the application of CFME-AuNPs/p-NiTSPc in real water and Mitosyl ointment samples. The recovery values of BHA were acceptable, ranging from 96 to 99% and demonstrating that the developed sensor is highly sensitive and effective for detecting trace amounts of BHA. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to investigate the individual electrochemical transients arising from local anodic events on stainless steel, to uncover the potential mechanisms producing different types of transients and to derive appropriate parameters indicative of the corrosion severity of such transient events. Design/methodology/approach: An equivalent circuit model was used for the transient analysis, which was performed using a local current allocation rule based on the relative instant cathodic resistance of the coupled electrodes, as well as the kinetic parameters derived from the electrochemical polarization measurement. Findings: The shape and size of the electrochemical current transients arising from SS 316 L were influenced by the film stability, local anodic dissolution kinetics and the symmetry of the cathodic kinetics between the coupled electrodes, where the ultralong transient might correspond to the propagation of film damage with a slow anodic dissolution rate. The dynamic cathodic resistance during the final stage of transient current growth can serve as a characteristic parameter that reflects the loss of passive film protection. Originality/value: Estimation of the local anodic current trace opens a new way for individual electrochemical transient analysis associated with the charges involved, local current densities and changes in film resistance throughout localized corrosion processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Faculty of Pharmacy of Ankara University / Ankara Üniversitesi Eczacilik Fakültesi Dergisi is the property of Ankara University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Faculty of Pharmacy of Ankara University / Ankara Üniversitesi Eczacilik Fakültesi Dergisi is the property of Ankara University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Plasma Electrolytic Oxidation (PEO) process was investigated to enhance the adhesion of AA2024-O aluminum alloy with a polyetherimide (PEI) matrix composite, using oxy-fuel welding (OFW). A Central Composite Design (CCD) statistical model was used to optimize three independent parameters in PEO: immersion time (s), duty cycle (%), and electrolyte concentration (Na2B4O7·10H2O), aiming to achieve a maximum value of shear strength of the hybrid joint (in MPa). The hybrid joint without PEO treatment presented a resistance of 2.2 MPa while the best condition presented a resistance of 9.5 MPa, resulting in a value 4× higher than the untreated material, due to the characteristics of the coating, which presented a more hydrophilic surface, allowing better mechanical interlocking with the polymer matrix and resulting in mixed-mode failure (adhesive, cohesive, and light fiber). In addition to improving adhesion, the PEO treatment provided better corrosion resistance to the alloy, forming an inert aluminum oxide (Al2O3) coating, with an improvement of approximately 99.84% compared to the untreated alloy. The statistical design covers about 77.15% of the total variability of the PEO + welding process, with independent factors influencing around 48.4% of the variability. [ABSTRACT FROM AUTHOR]

A novel graphene-modified molecularly imprinted polymer-based electrochemical sensor (MIP/RGO-GCE) was developed for the sensitive and selective detection of sibutramine in sports doping control. The sensor was fabricated by electropolymerizing o-phenylenediamine on a reduced graphene oxide-modified glassy carbon electrode in the presence of sibutramine as the template molecule. Under optimized conditions, the MIP/RGO-GCE sensor exhibited a wide linear range (0.05 to 20 μM), low detection limit (0.02 μM), high sensitivity (1.27 μA/μM), good precision (RSD < 2.7%), and long-term stability (93.5% retention after two weeks). The sensor's applicability was successfully demonstrated by analyzing spiked human urine and serum samples, with recoveries ranging from 95.8 to 103.2% and good agreement with the reference HPLC method. Furthermore, the sensor showed a rapid response time of 5 s and excellent reproducibility with an RSD of 1.5% for repeated measurements. The proposed sensor offers a rapid, cost-effective, and reliable alternative to traditional chromatographic methods for sibutramine detection in sports doping control. [ABSTRACT FROM AUTHOR]

Nitrogen and sulphur co-doped carbon quantum dots (N,S-CQDs) were obtained using a facile hydrothermal approach from a mixture of o-phenylenediamine and methionine. As developed N,S-CQDs displayed blue fluorescence, with a quantum yield of 21%. The characterization of N,S-CQDs was completed with UV-vis., FT-IR, PL, XRD, Raman, DLS, XPS, TEM, and electrochemical examinations. In this paper, we first illustrate the development of N,S-CQDs as a fluorescent sensor for detecting heavy metal ion Hg(II) in the linear range of 0–18 μM with a detection limit of 120 nM. The PL quenching of N,S-CQDs was primarily ascribed to the photoinduced electron transfer (PET) between N,S-CQDs and Hg(II) and dynamic quenching process. Secondly, we have developed N,S-CQD-modified platinum electrode (PtE/N,S-CQD) to serve as an electrochemical sensor for the efficient and selective recognition of Hg(II) ions with a wide linearity range of 10–60 nM and a low limit of detection of 2 nM. Both the developed sensors exhibit excellent recovery results for Hg(II) in drinking water and milk samples. Additionally, we have used the agar well diffusion method to examine the bactericidal efficacy of N,S-CQDs against both Gram-negative and Gram-positive bacterial strains. [ABSTRACT FROM AUTHOR]

SnO2 is a wide-band gap N-type semiconductor material with a higher electron transfer rate than TiO2. Therefore, SnO2 has broad application prospects in the photoanode composite materials of dye-sensitized solar cells (DSSC). In this study, SnO2–TiO2 composite nanofibers with different molar ratios (5%, 10%, 15%, and 20%) were prepared by double-needle electrospinning technology, and the nanofibers were characterized after adjusting the solution composition. Different molar ratios of TiO2 and SnO2–TiO2 composite nanofiber photoanodes were fabricated by spin-coating, and the adsorption behavior of dyes on the photoanodes was investigated. Moreover, the electrochemical impedance of the photoanodes and DSSC and their photoelectric performance were also tested. The experimental results showed that SnO2–TiO2 composite nanofibers with a molar ratio of 10% exhibited excellent properties, including a peak specific surface area of 93.01 m2/g, strong dye adsorption capacity, small interfacial resistance, and fast electron transfer rate. These outstanding properties significantly promoted the generation of photoelectrons and improved the photoelectric conversion efficiency of DSSC. Compared with single-component TiO2, the photoelectric conversion efficiency of SnO2–TiO2 nanofiber photoanode composite material improved by 85.65%. [ABSTRACT FROM AUTHOR]

Metal‐covalent organic frameworks (MCOF) as a bridge between covalent organic framework (COF) and metal organic framework (MOF) possess the characteristics of open metal sites, structure stability, crystallinity, tunability as well as porosity, but still in its infancy. In this work, a covalent organic framework DT‐COF with a keto‐enamine structure synthesized from the condensation of 3,3′‐dihydroxybiphenyl diamine (DHBD) and triformylphloroglucinol (TFP) was coordinated with Cu2+ by a simple post‐modification method to a obtain a copper‐coordinated metal‐covalent organic framework of Cu‐DT COF. The isomerization from a keto‐enamine structure of DT‐COF to a enol‐imine structure of Cu‐DT COF is induced due to the coordination interaction of Cu2+. The structure change of Cu‐DT COF induces the change of the electron distribution in the Cu‐DT COF, which greatly promotes the activation and deep Li‐storage behavior of the COF skeleton. As anode material for lithium‐ion batteries (LIBs), Cu‐DT COF exhibits greatly improved electrochemical performance, retaining the specific capacities of 760 mAh g−1 after 200 cycles and 505 mAh g−1 after 500 cycles at a current density of 0.5 A g−1. The preliminary lithium storage mechanism studies indicate that Cu2+ is also involved in the lithium storage process. A possible mechanism for Cu‐DT COF was proposed on the basis of FT‐IR, XPS, EPR characterization and electrochemical analysis. This work enlightens a novel strategy to improve the energy storage performance of COF and promotes the application of COF and MCOF in LIBs. [ABSTRACT FROM AUTHOR]

Anion exchange membrane fuel cell (AEMFC) technology is attracting intensive attention, due to its great potential by using non‐precious‐metal catalysts (NPMCs) in the cathode and cheap bipolar plate materials in alkaline media. However, in such case, the kinetics of hydrogen oxidation reaction (HOR) in the anode is two orders of magnitude sluggish than that of acidic electrolytes, which is recognized as the grand challenge in this field. Herein, we report the rationally designed Ni nanoparticles encapsulated by N‐doped graphene layers (Ni@NG) using a facile pyrolysis strategy. Based on the density functional theory calculations and electrochemical performance analysis, it is witnessed that the rich Pyridinic‐N within the graphene shell optimizes the binding energy of the intermediates, thus enabling the fundamentally enhanced activity for HOR with robust stability. As a proof of concept, the resultant Ni@NG sample as the anode with a low loading (1.8 mg cm−2) in AEMFCs delivers a high peak power density of 500 mW cm−2, outperforming all of those of NPMC‐based analogs ever reported. [ABSTRACT FROM AUTHOR]

Various integrated treatment methods have been extensively studied by researchers worldwide to effectively remove ammonium from different types of wastewater. In this study, a bibliometric analysis was conducted using VOSviewer software to provide an overview of the research trends in ammonium wastewater treatment technologies, based on data extracted from the Scopus database. The objective of this study is to analyse the growing interest in current ammonium removal technologies in terms of annual publications, leading journals, prominent authors, countries and institutions, author keywords, treatment methods, reactors, wastewater types, and novel approaches. A total of 1,451 publications were recorded between 1972 and 2020, indicating a continued increase in future publications. China emerged as the leading country, with the highest number of publications on this topic. Among 3,100 retrieved keywords, the most active keyword was "wastewater treatment" with 183 occurrences and has a strong link with keywords such as "nitrification". The keywords "anammox", "ion exchange", and "electrochemical oxidations" had the highest occurrences among biological, physical and chemical treatment methods. Besides, the keywords "sequencing batch reactor" and "domestic sewage" were found to be the most frequently used in studies on bioreactors and wastewater related to ammonium treatment. Several novel treatment methods, including "comammox", "feammox", and "advanced oxidation" were recorded as having the most recent publication years. This study provides information on ammonium removal technologies and helps future scholars to develop new ideas in the field of wastewater treatment. [ABSTRACT FROM AUTHOR]

The novel and exciting class of porphyrin‐based compounds are the main group coordination‐driven porphyrins (MGCPs) with a central main group element into the porphyrin macrocycle. MGCPs have unique properties, reactivity, and potential applications in catalysis, sensing, biomedicine etc. This comprehensive review article discusses recent advances in the field of main group coordination driven porphyrins and explores some of its potential uses in solar cells, catalysis, antimicrobial, optoelectronic devices, sensing, and catalysis. The addition of main group elements to porphyrin systems has resulted in the production of entirely novel compounds that have intriguing qualities including increased stability and catalytic activity. Significant modifications in these unique compounds features are apparent through the analysis of their structural properties. It encompasses FTIR, proton NMR, electrical and optical characterisation in addition to an electrochemical analysis of those parameters. They serve as significant building blocks for the creation of cutting‐edge materials and technologies in a variety of scientific and technical disciplines because to their special qualities and adaptability. Researchers working in the domains of coordination chemistry, catalysis, and materials science will find this study to be of interest since it offers a thorough examination of current developments in main group coordination driven porphyrins and their prospective applications. Overall, main group porphyrins are used in many different fields, such as sensing, catalysis, and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn–MnO2 batteries are attracting attention as a cost‐effective and safe energy storage solution, but their commercialization faces challenges due to limited stability, output voltage, and energy density. Herein, a hybrid‐ion Zn–MnO2 system with enhanced Mn4+/Mn2+ electrochemical contribution is introduced using an Al3+‐based electrolyte. Compared with conventional Zn2+ electrolytes, the hybrid Al3+/Zn2+ cell offers higher output voltage of 1.75 V, capacities up to 469 mAh g−1, and outstanding energy densities up to ≈730 Wh kg−1 at 0.3 A g−1. Besides, the Al3+‐enabled Zn–MnO2 battery shows 100% capacity and energy density retention after 10,000 cycles at 2 A g−1. Even at a high mass–loading of 6.2 mg cm−2, a capacity of ≈200 mAh g−1 is maintained for over 100 cycles. This outstanding performance is related to the contribution of different intercalation and reaction mechanisms, as proved by the combination of electrochemical analysis and ex‐situ x‐ray diffraction characterization of the cells at different discharge stages. Al3+ ions, as Lewis strong acid, contribute to capacity in two significant ways: through a highly reversible intercalation/de‐intercalation that substantially boosts capacitance at low current rates, and promoting the Mn4+/Mn2+ reaction aided by H+ that dominates the capacitance at higher current rates. Overall, this work demonstrates a practical Zn–MnO2 battery with a high potential for low‐cost stationary energy storage habilitated by multiple ion co‐intercalation. [ABSTRACT FROM AUTHOR]

With the aim of developing efficient non-noble metal catalysts for hydrogen evolution reaction (HER), this work synthesized a Ni–Se–Lu electrocatalyst by incorporating the rare earth element Lu to modify the Ni–Se electrode. The hydrogen evolution performance of the Ni–Se–Lu electrocatalyst under alkaline conditions was investigated on the basis of the micromorphology and structure of the electrode. In 1 M KOH solution, the Ni–Se–Lu electrode exhibited small overpotentials of 52 and 105 mV at current densities of 10 and 50 mA cm−2, respectively, along with a Tafel slope of 63.8 mV·dec−1. Electrochemical analysis results revealed increased active sites and electrochemically active surface area and improved surface roughness after the introduction of Lu element. Moreover, excellent stability in hydrogen evolution was demonstrated with a potential decay rate below 5% after 72 h of electrolysis. [Display omitted] • Ni–Se–Lu/NF electrocatalyst is developed via a facile and simple galvanostatic electrodeposition method. • Ni–Se–Lu/NF electrocatalyst showed excellent HER activity with low overpotential of 52 mV at 10 mA cm−2. • The excellent HER activity can be attributed to the increased intrinsic activity and accelerated electron transfer rate. [ABSTRACT FROM AUTHOR]

The hydrothermal preparation of catalytic NiPd x Co 2-x O 4 (x ≦ 0.08) nano-electrocatalysts on Ni foam (NF) was successfully accomplished. The morphology and chemical composition of the catalysts are confirmed by advanced analytical techniques XRD, SEM, EDX, TEM, HR-TEM, and XPS. The NiPd x Co 2-x O 4 (x = 0.06) NF nano-electrocatalyst demonstrated remarkable performance in the HER, with an overpotential of 191.6 mV, a Tafel slope of 84.7 mV/dec, and extraordinary stability over 24 h using chronopotentiometry methods. The surface and electrochemical analyses demonstrated that the sample, doping with a 6.0% Pd2+ concentration, had appreciably enhanced performance in the HER. The improvement may be attributed to a much larger electrochemical surface area and fast charge transfer kinetics at the semiconductor and electrolyte interface. The influence of Pd dopants on the HER performance of CNs is studied with the help of density functional theory. It elucidates the way in which hydrogen and water molecules bind to the surface of PCN slabs. The theoretical results suggest that the incorporation of Pd dopants enhances the electrocatalytic process and boosts the HER activity as the concentration of Pd increases. The density of state spectra reveals their effect on spin-dependent electronic structure characteristics. Our findings point to a practical path for creating distinctive electrocatalysts that will serve as better electrodes for a variety of forthcoming hydrogen fuel cell applications. • NiPd x Co 2-x O 4 (0.00 ≥ x ≦ 0.08) nano - electrocatalyst on Ni foam (NF) were synthesized successfully first time. • Pd doping concentration into NiPd x Co 2-x O 4 crystal structure enhanced the active sites tremendously. • The NiPd x Co 2-x O 4 (x = 0.06) electrocatalyst demonstrated remarkable performance in the HER. • Overpotential of 180.9 mV, a Tafel slope of 84.7 mV/dec mV at 10 mA cm-2, exceptional stability for 1000 cycles. • DFT for exploring and explaining the effect of Pd dopants on the catalytic and HER activity is elucidated. [ABSTRACT FROM AUTHOR]

Molecular electrocatalysis has emerged as a crucial branch of molecular electrochemistry, finding applications across various fields such as energy generation, electroanalysis, and electrosynthesis. In recent years, the study of these processes within confined spatial domains, has been increasingly frequent. However, a significant gap exists in the theoretical understanding of the interplay between different kinetics (redox and chemical) and mass transport under these conditions, and how their combined effects influence the electrochemical response. As a first step to address the aforementioned gap, this manuscript presents a theoretical expression for the current‐potential‐time response of a catalytic reaction occurring under finite diffusive conditions. The results indicate that, when the chemical kinetics is not fast, there are significant differences in electrochemical responses due to mass transport influences. Thus, in the case of bounded finite diffusion, a loss of efficiency in the process is observed, resulting in lower currents compared to those corresponding to semi‐infinite diffusive conditions. The validity of well‐known methods, such as the analysis of the current plateau or the foot of the wave under stationary conditions, is discussed. Experimental validation of these results is also provided through the study of the oxidation of Solketal mediated by the oxidation of TEMPO radical. [ABSTRACT FROM AUTHOR]

The sensitive nonenzymatic sensing of glucose has been made feasible for the first time using a nonthermal plasma (NTP)-synthesized ZnO nanostructure. This work presents an interesting and novel method for surface modification. The effects of flow gas of Argon/Oxygen (20, 30 and 40 l/min) on the Zn foil surface and various properties were investigated. Optical emission spectroscopy OES has been used to characterize transmissions for positive and negative systems of Ar/O plasma. X-ray diffraction showed close adjacent tops and the strongest peak at Zn (101). EDX displays the constants (Ok_α), (Znk_α) and (Znk_β) and change in (ZnL_α). Photoluminescence (PL) Analysis shows a shift at the vertex toward the left and then toward the right confirming the reaction of all PL spectra within a strong UV emission peak. Raman spectroscopy analysis demonstrates two clear peaks gradually shifting to the right with an increase in the percentage of gas flowing compared to the blank metal, and scanning electron microscopy (FE-SEM) images show changes in the shape of nanoparticles due to increasing gas flow, the surface of zinc metal is affected by cold plasma and forms particles with very small diameters ranging from 10.8nm to 123nm. Also altered the surface morphology where the nano shape changed from flower-like particles to sheets with diameters ranging 282.7–643.5nm and the sheets grew with the increase of gas flow to diameters ranging 132–710nm. ZnO nanostructures are employed as biosensor electrodes (nonenzymatic) glucose as the increase in current is proportional to the flowing gas (2.06E-03mA, 2.09E-03mA and 4.34E-03mA). [ABSTRACT FROM AUTHOR]

This investigation explores the impact of incorporating graphene (Gr) reinforcement on the microstructure, mechanical properties, corrosion behavior, and biocompatibility of a composite derived from a magnesium–calcium (Mg–Ca) alloy. Two concentrations of Gr (0.1% and 0.2%) were introduced to an Mg–Ca alloy. The addition of 0.1% Gr resulted in a refined grain structure, enhancing both tensile and compression strength. However, electrochemical analysis and immersion testing revealed an increase in corrosion rate (Rw${R}_w$) with the incorporation of Gr. Although the corrosion rate of the Mg–Ca‐0.1%Gr composite was comparable to that of Mg–Ca, the Mg–Ca–0.2%Gr exhibited higher corrosion rates attributed to the enhancement of micro‐galvanic corrosion. Interestingly, cell survival rate tests demonstrated improved biocompatibility for the Mg–Ca–0.1%Gr sample, emphasizing its potential for applications in the biomedical domain, which requires enhanced mechanical strength, corrosion resistance, and biocompatibility. [ABSTRACT FROM AUTHOR]

Background: Nitric oxide (NO) is a strong vasodilator, selectively directed on pulmonary circulation through inhaled administration. In adult intensive care units (ICU), it is mainly used for refractory hypoxemia in mechanically ventilated patients. Several medical delivery devices have been developed to deliver inhaled nitric oxide (iNO). The main purpose of those devices is to guarantee an accurate inspiratory NO concentration, whatever the ventilator used, with NO2 concentrations lower than 0.3 ppm. We hypothesized that the performances of the different available iNO delivery systems could depend on their working principle and could be influenced by the ventilator settings. The objective of this study was to assess the accuracy of seven different iNO-devices combined with different ICU ventilators' flow-by to reach inspiratory NO concentration targets and to evaluate their potential risk of toxicity. Methods: We tested seven iNO-devices on a test-lung connected to distinct ICU ventilators offering four different levels of flow-by. We measured the flow in the inspiratory limb of the patient circuit and the airway pressure. The nitric oxide/nitrogen (NO/N2) flow was measured on the administration line of the iNO-devices. NO and NO2 concentrations were measured in the test-lung using an electrochemical analyzer. Results: We identified three iNO-device generations based on the way they deliver NO flow: "Continuous", "Sequential to inspiratory phase" (I-Sequential) and "Proportional to inspiratory and expiratory ventilator flow" (Proportional). Median accuracy of iNO concentration measured in the test lung was 2% (interquartile range, IQR -19; 36), -23% (IQR -29; -17) and 0% (IQR -2; 0) with Continuous, I-Sequential and Proportional devices, respectively. Increased ventilator flow-by resulted in decreased iNO concentration in the test-lung with Continuous and I-Sequential devices, but not with Proportional ones. NO2 formation measured to assess potential risks of toxicity never exceeded the predefined safety target of 0.5 ppm. However, NO2 concentrations higher than or equal to 0.3 ppm, a concentration that can cause bronchoconstriction, were observed in 19% of the different configurations. Conclusion: We identified three different generations of iNO-devices, based on their gas administration modalities, that were associated with highly variable iNO concentrations' accuracy. Ventilator's flow by significantly impacted iNO concentration. Only the Proportional devices permitted to accurately deliver iNO whatever the conditions and the ventilators tested. [ABSTRACT FROM AUTHOR]

Year after year, the need for decentralized tools to tackle the monitoring of heavy metal levels in the environment gradually increases. In this context, suitable electrochemical methodologies are widely established and particularly attractive for the production of low-cost miniaturized field-deployable analytical platforms. This work focused on the development of an automatable portable system based on square-wave anodic stripping voltammetry (SWASV) for the on-line detection of heavy metals. The surface of the sensors is appropriately modified and coupled with a fluidic system equipped with an ad-hoc designed flow cell. A custom software tool was introduced to handle the remote-controlled potentiostat and automate the various steps of the procedure, including stirring operations, cleaning phases, SWASV measurements, and data collection. After studying technical and analytical challenges, the final system developed was applied to the simultaneous detection of Cd(II), Pb(II), and Cu(II) in solution, achieving sub-ppb detection limits. Additionally, the practical applicability of the method was successfully applied to river water samples collected from the Loire basin in France. [ABSTRACT FROM AUTHOR]

The ability of analytical strategies to detect and positively identify molecules under extremely dilute conditions is important for the growth and expansion of analytical techniques and instrumentation. At present, few measurement science techniques can robustly approach the measurement of just a few thousand molecules. Here, we present an electrochemical platform for the detection and positive identification of fewer than 1000 molecules of decamethylferrocene ((Cp*)2FeII). We achieve this remarkable detection threshold by trapping (Cp*)2FeII in a 1,2-dichloroethane microdroplet, which is allowed to dissolve into an aqueous continuous phase while on a gold microelectrode (radius ∼6.25 μm). Because electrochemistry is not sensitive enough to observe the charge of less than 1000 molecules, we dissolved μM amounts hexacyanoferrate(III) in the aqueous continuous phase. The biphasic reaction between hexacyanoferrate(III) and Cp2*(Fe)II allows for a feedback loop when the microelectrode is biased sufficiently negative to reduce Cp2*(Fe)III. This feedback loop, a typical EC′ catalytic mechanism, amplifies the electrochemical signal of Cp2*(Fe)II when the droplet is of small enough dimensions for feedback to occur. Our results demonstrate that clever biphasic reactions can be coupled with dissolving microdroplets to access extremely low limits of quantitation in electroanalysis. [ABSTRACT FROM AUTHOR]

The electronic structure of molybdenum carbide closely resembles that of Pt, making it a promising candidate material for replacing noble metal catalysts. However, the primary challenge is the controlled and eco-friendly synthesis of molybdenum carbide. Herein, we developed a sustainable and controlled method for synthesizing a heterostructure catalyst for the electrocatalytic hydrogen evolution reaction (HER) using starch as the raw material. Through a hydrothermal redox reaction and subsequent temperature-programmed treatment under an inert atmosphere, the hexagonal Mo 2 C-cubic MoC heterostructure nanoparticles were dispersed on a carbon matrix. Our investigation into the synthesis process extensively covered the growth of MoO 2 nanocrystals and hydrochar during the hydrothermal redox reaction, as well as the phase evolution during the subsequent temperature-programmed treatment. Electrochemical assessments demonstrated the catalyst's remarkable efficiency for the hydrogen evolution reaction across both acidic and alkaline media, achieving a current density of 10 mA/cm2 with an overpotential of 139.4 mV in 1 M KOH solution and 160.7 mV in 0.5 M H 2 SO 4 solution. Combining a series of electrochemical characterizations and applying the distribution of relaxation times (DRT) analysis to operando electrochemical impedance spectroscopy (EIS) data, the superior kinetic performance of the Mo 2 C–MoC/C was demonstrated, outperforming that of single-phase molybdenum carbide. Furthermore, the catalyst has demonstrated remarkable stability even at high current densities in both acidic and alkaline electrolytes, underscoring its potential as a cathode catalyst in both alkaline water electrolyzers and proton exchange membrane (PEM) electrolyzers. Hexagonal Mo 2 C-cubic MoC heterostructure is fabricated as a high performance electrocatalyst for hydrogen evolution. This work underscores the significance of the precise synthesis of multi-phase catalysts. [Display omitted] • Starch-derived nanoscale molybdenum carbide heterostructure. • Systematic study of the synthesis process of the catalyst. • Excellent catalytic activity and stability under acidic and alkaline media. • DRT analysis visually reveals the catalyst's superior HER kinetics. [ABSTRACT FROM AUTHOR]

Asymmetric metalloporphyrins are potential electrocatalysts to construct composites for efficient oxygen reduction reactions (ORRs) due to their inherent large dipole moment, which facilitates the charge separation. To find more effective molecular structures towards the ORRs, in particular their performance and electrolyte relationship, we rationally designed two A3B-type asymmetric cobalt porphyrin aPh-TCoP and aBA-TCoP with phenyl and benzoic acid as substituents, respectively. The ORR performance of the porphyrin-decorated carbon black composites was examined in five electrolytes at different pH values spanning from 0.7 to 13.7. It was found that aBA-TCoP/C exhibited better ORR activity and selectivity than aPh-TCoP/C in all solutions. Interestingly, both composites demonstrated their highest ORR activity in the pH13.7 electrolyte and exhibited 4-electron selectivity in the pH3.7 solution. This conclusion is drawn from a comprehensive analysis of various electrochemical properties, encompassing current density, reduction potentials, electron transfer numbers, and intermediate yields. The results illustrate the regulation of ORR properties by altering the electrolyte pH and a notable improvement in the ORR performance through the modification of porphyrin substituents. These findings offer a foundational understanding for the design of efficient metalloporphyrins and the attainment of controlled oxygen reduction in electrochemical devices. [Display omitted] • A3B-type asymmetric cobalt porphyrins are designed for oxygen reduction. • Molecular electronic structures are calculated using density functional theory. • A universal pH range is used to examine the ORR properties. • Greater ORR performance is achieved by aBA-TCoP/C than aPh-TCoP/C. • Both composites exhibit the best activity at pH13.7 and 4-electron selectivity at pH3.7. [ABSTRACT FROM AUTHOR]

Current global 3D metal printing research is focused on powder bed fusion and direct energy deposition. Several materials are presently under research to assess their post-additive manufacturing properties, and to process them in industries using advanced manufacturing techniques. This study investigates the electrochemical, mechanical, and metallurgical properties of wire arc additively manufactured (WAAM) ER70S-6 alloy walls on AISI S235 plates, emphasizing ship component fabrication. The corrosion resistance of both materials is assessed through Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization testing in a 3.5% NaCl solution. Surface and cross-sectional morphologies are analyzed using optical microscopy and scanning electron microscopy, while energy dispersive spectroscopy is employed to study the chemical composition of the corrosion products. Moreover, the hardness of the WAAM-deposited ER70S6 wall is found to be highest in the uppermost layers of deposition due to the presence of acicular ferrite and ferritic-bainite microstructure. Tensile and Charpy impact strength for AISI S235 and WAAM-deposited ER70S-6 exhibit similar performance at room and low temperatures. Interestingly, the WAAM sample demonstrates a 60% higher elongation than the AISI S235 sample. Hence, the findings from this experimental work suggest that WAAM-deposited carbon steel exhibits favourable corrosion resistance and comparable mechanical properties to AISI S235. Consequently, WAAM is emerging as a promising alternative to conventional manufacturing techniques for fabricating ship components, repairing and modifying hull structures, manufacturing nozzles, propeller blades, fin-like structures, structural components, and more. [ABSTRACT FROM AUTHOR]

An experimental study has been conducted to develop unique zinc-rich coatings for the protection of low carbon steel reinforcements. These coatings are applied to low carbon steel substrates and subjected to various temperatures (100 °C, 150 °C, 200 °C, and 250 °C) to assess their mechanical integrity, corrosion resistance, and durability, replicating extreme service environments. The study integrates different nanoparticle concentrations into the zinc matrix (including Zn only, 50% Zn + 50% TiO2, 50% Zn + 30% WC + 20% TiO2, 40% Zn + 40% Ni-Cr Alloy + 20% TiO2, 70% Zn + 30% WC, and 50% Zn + 50% Ni-Cr Alloy) to assess their reinforcement effectiveness and contribution to thermal stability. The performance properties are assessed using adhesion tests, coating ratings, hardness assessments, electrochemical analysis, and field emission scanning electron microscopy (FESEM). The findings reveal that zinc coatings with a composition of 50% Zn, 30% WC, and 20% TiO2 provide excellent adhesion, particularly beneficial for high-temperature applications. Coatings containing Ni-Cr alloy display outstanding thermal stability, a vital characteristic for withstanding high-temperature conditions. At 250 °C, evaluating the compositions for the most favorable potential at the highest current densities is imperative. Microstructural analysis from room temperature to 250 °C shows a significant improvement in the integration and refinement of WC and Ni-Cr within the Zn matrix, resulting in the coatings' optimal performance. [ABSTRACT FROM AUTHOR]

Titanium carbide (TiC) coatings were prepared on the surface of AlFeCoCrNiCu high-entropy alloy blocks using electro-spark deposition (ESD). The microhardness and corrosion resistance of the TiC coatings prepared under different voltage and capacitance process parameters were studied. The research shows that the maximum microhardness of the TiC coating on sample 4 (working voltage of 20 V, working capacitance of 1000 μF) is 844.98 HV, which is 81.5% higher than the microhardness of the substrate. This is because the deposition energy increases with the increase in voltage, and the adhesion and aggregation between the coating and the substrate are enhanced, increasing the hardness of the coating. It is worth noting that excessive deposition energy can increase surface defects and reduce the microhardness of the coating surface. Electrochemical testing analysis shows that the corrosion current density of the TiC coating is the lowest (9.475 × 10−7 ± 0.06 × 10−7), and the coating impedance is the highest (2.502 × 103 Ω·com2). The absolute phase angle value is the highest (about 72°). The above indicates that the TiC coating prepared with a working voltage of 20 V and a working capacitance of 1000 μF has better microhardness and corrosion resistance. [ABSTRACT FROM AUTHOR]

Corrosion deterioration of materials is a major problem affecting economic, safety, and logistical issues, especially in the aeronautical sector. Detecting the correct corrosion type in metal alloys is very important to know how to mitigate the corrosion problem. Electrochemical noise (EN) is a corrosion technique used to characterize the behavior of different alloys and determine the type of corrosion in a system. The objective of this research is to characterize by EN technique different aeronautical alloys (Al, Ti, steels, and superalloys) using different analysis methods such as time domain (visual analysis, statistical), frequency domain (power spectral density (PSD)), and frequency–time domain (wavelet decomposition, Hilbert Huang analysis, and recurrence plots (RP)) related to the corrosion process. Optical microscopy (OM) is used to observe the surface of the tested samples. The alloys were exposed to 3.5 wt.% NaCl and H2SO4 solutions at room temperature. The results indicate that HHT and recurrence plots are the best options for determining the corrosion type compared with the other methods due to their ability to analyze dynamic and chaotic systems, such as corrosion. Corrosion processes such as passivation and localized corrosion can be differentiated when analyzed using HHT and RP methods when a passive system presents values of determinism between 0.5 and 0.8. Also, to differentiate the passive system from the localized system, it is necessary to see the recurrence plot due to the similarity of the determinism value. Noise impedance (Zn) is one of the best options for determining the corrosion kinetics of one system, showing that Ti CP2 and Ti-6Al-4V presented 742,824 and 939,575 Ω·cm2, while Rn presented 271,851 and 325,751 Ω·cm2, being the highest when exposed to H2SO4. [ABSTRACT FROM AUTHOR]

The scalable fabrication of cost-efficient bifunctional catalysts with enhanced hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance plays a significant role in overall water splitting in hydrogen production fields. MoSe2 is considered to be one of the most promising candidates because of its low cost and high catalytic activity. Herein, hierarchical nitrogen-doped carbon networks were constructed to enhance the catalytic activity of the MoSe2-based materials by scalable free-drying combined with an in situ selenization strategy. The rationally designed carbonaceous network-encapsulated MoSe2 composite (MoSe2/NC) endows a continuous honeycomb-like structure. When utilized as a bifunctional electrocatalyst for both HER and OER, the MoSe2/NC electrode exhibits excellent electrochemical performance. Significantly, the MoSe2/NC‖MoSe2/NC cells require a mere 1.5 V to reach a current density of 10 mA cm−2 for overall water splitting in 1 M KOH. Ex situ characterizations and electrochemical kinetic analysis reveal that the superior catalytic performance of the MoSe2/NC composite is mainly attributed to fast electron and ion transportation and good structural stability, which is derived from the abundant active sites and excellent structural flexibility of the honeycomb-like carbon network. This work offers a promising pathway to the scalable fabrication of advanced non-noble bifunctional electrodes for highly efficient hydrogen evolution. [ABSTRACT FROM AUTHOR]