Precipitin Research Articles

Simultaneous immobilization of sediment internal phosphorus, arsenic and tungsten by lanthanum carbonate capping

In this study, lanthanum carbonate (LC) was selected as a capping agent to examine its effectiveness in immobilizing sediment internal phosphorus (P), arsenic (As) and tungsten (W). With a 180-day incubation experiment, it was determined that LC capping efficiently reduced the concentrations of soluble reactive P (SRP), soluble As and soluble W in pore water, with the highest reduction rate of 83.39%, 56.21% and 68.52%, respectively. The primary mechanisms involved in the adsorption of P, As and W by LC were precipitation reactions and ligand exchange. Additionally, P, As and W were immobilized by LC capping through the transformation of fractions from mobile and less stable forms to more stable forms. Furthermore, LC capping led to an increase in the Eh value, which promoted the oxidation of soluble Fe (Ⅱ) and soluble Mn. The significantly positive correlation and synchronized variations observed between SRP, soluble As, soluble W, and soluble Fe (II) indicated that the effects of LC on Fe redox played a crucial role in immobilizing sediment internal P, As and W. However, the oxidation of Mn, promoted by LC, played a more significant role in immobilizing sediment internal As than P and W. These effects resulted in LC capping achieving the highest reduction of SRP, soluble As and soluble W flux at 145.22, 22.19, and 0.58 μg m−2d−1. It is of note that LC capping did not lead to an elevated release hazard of Co, Ni, Cu, and Pb, barring Cd. Besides, LC capping did not modify the entire microbial communities in the sediment, but altered the proportional representation of specific microorganisms. Generally, LC has potential as a capping agent capable of simultaneously immobilizing sediment internal P, As and W.

Phytochemical Evaluation and Determination of the Content of Some Natural Antioxidants (Polyphenols and Flavonoids) from Ficus Capensis, Newbouldia laevis and Carpolobia lutea

Scientific interest in the search for natural antioxidants (secondary metabolites) from medicinal plants has increased considerably in recent years, due to the involvement of free radicals in the genesis of many diseases. The aim of the present study is to determine qualitatively and quantitatively the secondary metabolites of aqueous and hydroethanol extracts from the leaves of the medicinal plants under investigation. Qualitative determination is based on staining and/or precipitation reactions, while quantitative determination is based on the assay of secondary metabolites. The results of their qualitative determinations revealed an abundance of polyphenols and saponins, a significant presence of flavonoids and anthocyanins, and a moderate presence of alkaloids, terpenes and catechic tannins in the aqueous extract. In the hydroethanol extract, on the other hand, there is an abundance of flavonoids, a significant presence of polyphenols, saponins and anthocyanins, and a moderate presence of alkaloids, terpenes and catechic tannins. Gallic tannins and quinones are absent in both extracts. While their quantitative assay revealed an abundance of flavonoids (314.51±5.14 mgEAG/g extract) and total polyphenols (66.19±2.44 mgEQ/g extract). Thus, the high flavonoid and polyphenol content of the various extracts (aqueous and hydroethanolic) of the leaves of the plants studied would justify their use in traditional medicine in the care of sickle-cell patients.

Cuprous ions influence on the biocorrosion of a carbon steel in the presence of sulphate reducing bacteria marine biofilm

The influence of marine sulphate reducing bacteria (SRB) biofilm on naval carbon steel corrosion in seawater was studied in the presence or not of cuprous ions as polluting agent. The optical density measurement showed that a concentration of 15 mg L−1 in cuprous ions can cause a significant slowdown in the proliferation of planktonic bacteria. However, electrochemical impedance results indicated that there was still bacterial activity on the metal substrate. Indeed, biofilm was grown on the surface of material in seawater containing SRB. Initially, an increase in the charge transfer resistance values due to the iron sulphide layer formed by the bacteria precipitation reactions was recorded during growth phase. This film acts as a barrier, preventing further oxidation of the underlying metal; then, the localized breakdown of iron sulphide layer generates an acceleration of corrosion. Similar behaviour occurs in the presence of sulphate reducing bacteria flora with 15 mg L−1 cuprous ions. In order to protect themselves when the seawater media containing toxic metals, sulphate reducing bacteria embed into clusters and increase the production of extracellular polymeric substances on materials. Sulphur was present on specimens in both cases and EDS spectra revealed the formation of iron sulphide. After the removal of biofilm, carbon steel surfaces exhibited a plenty of micropits scattered on the entire surface compared to the surface immersed in the seawater without bacteria.

Mechanism study of composite co-deposited Cu/Co-Mo corrosion-resistant coating on 6061 Al alloy

To improve the bonding strength of the 6061 Al alloy with the plating layer and enhance the corrosion resistance, a Cu/Co-Mo corrosion-resistant plating layer was deposited on its surface. Through Scanning Electron Microscope, it is found that Cu/Co-Mo and the substrate can form an obvious three-layer composite structure, and X-ray diffraction detects that the CoMo coating is an alloy with obvious amorphous characteristics, and its phase composition is Co3Mo. After performance testing, the composite coating improved the corrosion resistance and hardness of the substrate and could play a good role in protecting the 6061 Al alloy. In addition, the mechanism of induced codeposition of CoMo alloy was investigated, and the deposition of Mo6+ was determined by cyclic voltammetry to be a three-step six-electron irreversible reduction reaction. Chronopotentiometry revealed that Mo6+ underwent a diffusion-controlled transient nucleation process. The AC impedance indicated that the selection of a suitable voltage is beneficial to reduce the hydrogen precipitation reactions during electrodeposition.

Creep behaviour and microstructure evolution in Super 304H–P92 heterogeneous welds

ABSTRACT The paper deals with results of long-term stress rupture tests on “cross-weld“ specimens made of Super 304 H – P92 heterogeneous welds. Stress rupture tests were carried out at temperatures of 625°C and 650°C up to 20,000 hours to rupture. Creep rupture strength and WSF values of Super 304 H – P92 welds for 10,000 hours at both 625°C and 650°C were calculated. The preferential location of failure was the intercritical part of the heat affected zone in P92 steel. Hardness of both base materials did not show significant changes during creep exposure at both 625°C and 650°C. However, gradual hardening of the weld metal occurred. Metallographic studies were performed in individual parts of heterogeneous welds. A special attention was paid to precipitation reactions in both base materials and heat affected zones. A residual content of vanadium in Super 304 H steel affected precipitation processes. Vanadium partly substituted niobium in the modified Z-phase ((V,Nb)CrN).

Effect of mixed manure on selected chemical properties, and phosphorus adsorption characteristics of Vertisols in Haramaya district, eastern Ethiopia

AbstractThe phosphorus (P) fixing behaviors of Vertisols have been identified as one of the key drivers of crop response to fertilizer application. More than 75% of applied P in tropical soil was found to be inaccessible to crops due to adsorption and precipitation reactions. A pot experiment was carried out to investigate the effect of mixed manure (MM) on P adsorption characteristics and other selected Vertisol properties. The soil was amended with 0, 5, 10, and 15 t ha−1 of MM. Changes in selected soil parameters and P adsorption characteristics were evaluated after a 30‐day incubation period. An analysis of variance was used to analyze the data. The results demonstrated a substantial drop in soil pH and an increase in soil organic carbon, total nitrogen, available P, and cation exchange capacity compared to the control. The overall quantity and efficiency of adsorbed P were drastically reduced as a result of MM rates. Moreover, the interaction effect of MM and added P concentration demonstrated a considerable increase in both the quantity and efficiency of adsorbed P. Both parameters increased with increased rates of added P concentration but decreased with increasing rates of MM. Despite the fact that all treatments fit well to both the Freundlich and Langmuir isotherms, the former was used due to its greater R2 value. When compared with the control, the Freundlich adsorption coefficient and intensity were found substantially lower. As a result, MM treatment boosted P availability by decreasing adsorption and associated Vertisols characteristics.

Spreadsheet Methodology for the Calculation of Equilibrium Diagrams Including Precipitation Reactions and Formation of Mixed Ligand and Polynuclear Hydroxo Complexes

Spreadsheet Methodology for the Calculation of Equilibrium Diagrams Including Precipitation Reactions and Formation of Mixed Ligand and Polynuclear Hydroxo Complexes

Hydrogen trapped by the precipitates of microalloying elements (Nb, Ti, and V) in low C ferritic steels: A quantitative analysis

A quantitative approach is presented here that studies the H trapped by the precipitates of microalloying elements (Nb, Ti, and V) in low C ferritic steels. Three model steels, each with one of the three microalloying elements, were prepared in the laboratory and subjected to aging treatment after solutionizing to achieve precipitates in ferrite. The precipitation reactions in the alloys were simulated using the TC-PRISMA module in Thermo-Calc software (databases: TCFE11 and MOBFE6) and subsequently validated using a small-angle neutron scattering (SANS) study. The H trapping abilities in the aged alloys were estimated after saturation H charging using electrochemical means and correlated with the volume fraction, number density, size, and interface character of the precipitates (all estimated using SANS). The relative H trapping ability of the precipitates was estimated as TiC > NbC > VC. The optimum aging conditions to achieve the best H trapping abilities were identified. Moreover, the maximum number of H atoms that can be trapped at the precipitate-ferrite interfaces were estimated based on the geometric considerations using SANS-estimated precipitate quantifications for each alloy. Subsequently, it was argued that the total quantity of trapped H by these precipitates can be explained if H remains trapped within the precipitate bodies in addition to those trapped at interfaces.

Numerical modeling of geological sequestration of brine wastewater due to coal mining in the Ordos Basin, China

The coal resources play an indispensable role in the development of heavy industry in China, and coal mining activity leads to brine wastewater drainage, causing major risks for the aquatic environmental system. Thus, the effective and economic treatment of coal mine wastewater is vital to mitigate the environmental burdens, and geological sequestration by deep-well injection is a promising treatment technique. This study elucidates the physical and geochemical processes of coal mine wastewater transport in deep reservoirs and proposes an optimized injection scheme to satisfy environmental and economic benefits simultaneously in the Ordos Basin, China. First, a variable density and variable parameter groundwater reactive transport model is constructed to simulate the long-term process of deep-well injection for coal mine wastewater treatment. Then, the environmental metrics, i.e., the percentage of permeability reduction, the total mass and spatial second moment of the wastewater plume, and the economic metric defined as achieving a higher concentration at a higher injection rate are proposed to evaluate the performance of the injection scheme. The simulation results show that the secondary mineral anhydrite dominates the reduction of reservoir permeability due to the precipitation reactions with SO42− in the brine wastewater, and the permeability in the reaction zone decreases by 0.66 % ~ 1.26 % after 10 years in the basic scenario. Moreover, higher concentrations negatively affect reservoir permeability and increase total dissolved solids, while higher injection rates decrease reservoir permeability and increase the brine wastewater plume. The study also identifies promising schemes that can achieve an optimal trade-off between the conflicting metrics. Based on the economic and environmental benefits demanded in this study, an injection scenario with a concentration of C4 and an injection volume of 800 m3/d is recommended to maximize environmental benefits. Overall, this numerical study offers significant implications for designing an economically and environmentally sustainable treatment injection scheme for coal mining wastewater drainage.

Electrodeposition of Fe-Ni Alloy Films having Invar Compositions with Fe3+ as the Sole Iron Source

Fe-Ni alloy films with invar alloy compositions were electrodeposited from a stable citrate bath containing trivalent iron ions (Fe3+) as the sole iron source. This bath was prepared based on determining the equilibrium constants for acid dissociation, complex formation and precipitation reactions. Electrodeposition was conducted under galvanostatic conditions at 25 °C without agitation and an investigation was carried out into the effects of pH and current density on the composition and microstructure of the films. The results showed that ferric hydroxide (Fe(OH)3), which is normally poorly soluble, did not precipitate after electrodeposition. Fe-Ni alloy films containing 31‒42 mass% Ni (including Fe-36 mass% Ni) were formed with a current efficiency of approximately 70%. The films were smooth and were made up of grains with sub-micron sizes, although some cracks were observed. Fe and Ni were distributed homogeneously throughout the films and the Fe-Ni solid solutions exhibited both face-centered cubic and body-centered cubic structures.

Single-step hydrothermal synthesis of biochar from waste industrial hemp stalk core for Pb2+ sorption: Characterization and mechanism studies

Industrial hemp stalk core (IHSC)-driven hydrothermal biochars were synthesized by single-step hydrothermal with different H2SO4 concentrations as hydrothermal media for the first time. The characterization results indicated that the concentration of H2SO4 had a significant effect on the carbonization degree and affected the physicochemical properties of biochar, which in turn influenced the Pb2+ sorption ability. Among these biochars, the 50% H2SO4-activated hydrothermal biochar (HBS50) not only achieved a significant yield (49.2%), but also obtained the largest specific surface area (359.11 m2/g) and pore volume (0.357 cm3/g). Besides, the abundant functional groups were found to be exposed on the surface of HBS50. In particular, HBS50 showed excellent sorption capacity for Pb2+, reaching a maximum sorption capacity of 195.9 mg/g in a short period of time (2 h). Sorption performance of HBS50 conformed well to the Langmuir isotherm model and pseudo-second order model. Based on the sorption performance and characterization analysis, the sorption mechanisms were proposed: -OH and -COOH groups on surface of biochar took deprotonation firstly to form negatively groups and then attracted Pb2+ cations. Subsequently, most of these attracted Pb2+ cations were further fixed by surface -OH and -COOH through complex reaction. In addition, the contribution of π-π coordination with unsaturated groups (such as CC and COOR) and the electrostatic interaction for the further attachment of Pb2+ cations could not be excluded. However, ion exchange and precipitation reaction had little assistance to the sorption of Pb2+. The work offers an effective and economic method for removing aqueous Pb2+.

Capturing the Dynamic Processes of Porosity Clogging

AbstractUnderstanding mineral precipitation induced porosity clogging and being able to quantify its non‐linear feedback on transport properties is fundamental for predicting the long‐term evolution of energy‐related subsurface systems. Commonly applied porosity‐diffusivity relations used in numerical simulations on the continuum‐scale predict the case of clogging as a final state. However, recent experiments and pore‐scale modeling investigations suggest dissolution‐recrystallization processes causing a non‐negligible inherent diffusivity of newly formed precipitates. To verify these processes, we present a novel microfluidic reactor design that combines time‐lapse optical microscopy and confocal Raman spectroscopy, providing real‐time insights of mineral precipitation induced porosity clogging under purely diffusive transport conditions. Based on 2D optical images, the effective diffusivity was determined as a function of the evolving porous media, using pore‐scale modeling. At the clogged state, Raman isotopic tracer experiments were conducted to visualize the transport of deuterium through the evolving microporosity of the precipitates, demonstrating the non‐final state of clogging. The evolution of the porosity‐diffusivity relationship in response to precipitation reactions shows a behavior deviating from Archie's law. The application of an extended power law improved the description of the evolving porosity‐diffusivity, but still neglected post‐clogging features. Our innovative combination of microfluidic experiments and pore‐scale modeling opens new possibilities to validate and identify relevant pore‐scale processes, providing data for upscaling approaches to derive key relationships for continuum‐scale reactive transport simulations.

Enhanced mineralization of bisphenol A by electric arc furnace slag: Catalytic ozonation

The catalytic ozonation of bisphenol A (BPA) was performed using an industrial solid waste as catalyst: electric arc furnace slag (EAFS). The characterization of the catalyst (SEM/EDS, XRD, surface area, pHPZC and Mössbauer spectroscopy) showed low surface area, alkaline nature and a composition rich in Fe, Ca, Si, C oxides, with minor content of Mg, Mn and Al. Ozonation experiments were carried out in a semi-batch reactor at room temperature at different initial pH conditions: from alkaline (natural pH 10.5) to acidic (controlled pH 3) aqueous media. Catalytic ozonation experiments showed complete BPA removal and remarkable total organic carbon conversions (62–80 %) over the broad pH range explored. The highest mineralization levels were obtained under basic pH, which was attributed to the generation of hydroxyl radical given by the presence of OH− and precipitation reactions of intermediates promoted by Ca oxides. Under acidic conditions the presence of EAFS notoriously enhanced BPA mineralization compared to single ozonation, due to the activity of leached species. The stability of the material was tested in 4 ozonation cycles. EAFS activity was mostly sustained under acidic conditions while a reduction was observed under uncontrolled pH condition, which was associated with a marked pH decrease. However, the residual activity still allowed complete BPA degradation and high mineralization levels (> 50 %). EAFS is a low-cost material that exhibits high activity and reasonable stability in catalytic ozonation of BPA. The valorization of this waste constitutes a technological alternative that could benefit both metallurgical and water treatment plants.

Phytochemical study and characterization of the fixed oil, extracted from the fruits of Gardenia ternifolia

This present study concerns the phytochemical study and the characterization of the fixed oil of the fruits of Gardenia ternifolia which is a plant recognized in several African pharmacopoeias for its therapeutic virtues. Its fruits, leaves and roots are used for the treatment of several infections. Thus, the overall objective of this study is to contribute to the valorization of Gardenia ternifolia fruits in phytomedicine and agri-food. Phytochemical screening is carried out using standard methods, based on coloring and precipitation reactions. The extraction of the fixed oil was done using a Soxhlet, providing an estimated yield of 3%. The evaluation of the chemical parameters of this oil according to the AFNOR standards (French Association for Standardization) made it possible to obtain the following results: iodine index (𝐼𝐼) = 5.6 ± 0.07 𝑔𝐼 /100 𝑔𝑐𝑔; acid value (𝐼𝐴) = 137.2 ± 0.001 𝑚𝑔𝐾𝑂𝐻/𝑔𝑐𝑔; saponification index (𝐼𝑆) = 201.6 ± 0.04 𝑚𝑔𝐾𝑂𝐻/𝑔𝑐𝑔; peroxide index (𝐼𝑃) = 8.4 ± 0.03 𝜇𝑔𝑂2/𝑔𝑐𝑔 and ester index (𝐼𝐸) = 64.4 ± 0.039 𝑚𝑔𝐾𝑂𝐻/𝑔𝑐𝑔. Ultimately, with much higher extraction quantities, the fruit oil of Gardenia ternifolia can present an interesting and valuable pharmaco-nutritional potential in the food industry and in pharmacology.

Secondary metabolites, antiradical and antibacterial activities of Pteleopsis leaves and trunk bark suberosa, plant used in Benin to treat toothache

Among the most common health problems worldwide, toothache is often cited and is often treated with herbal medicines to relieve the pain and inflammation associated with it. The present work reports the preliminary phytochemical analysis, antiradical and antibacterial activities of leaves and trunk bark of Pteleopsis suberosa, a plant highly sought after in traditional medicine in Benin to treat toothache. Secondary metabolites were identified by staining and precipitation reactions specific to each metabolite family. Total phenols were determined by the Folin Ciocalteu method. The aluminum trichloride method was used to quantify total flavonoids, while the determination of condensed tannins was carried out by the hydrochloric vanillin method. The antiradical activity of the extracts was evaluated by 2,2-diphenyl-l-picrylhydrazyl and the antibacterial activity by the dilution method in microplates and Petri dishes. Leaves and bark of Pteleopsis suberosa trunk contain tannins, flavonoids, anthocyanins, leuco-anthocyanins, a reducing compound. Ethanol extract of Pteleopsis leaves suberosa (IC 50 =0.0015 μg / μL) showed more interesting anti-radical activity than butylhydroxytoluene (IC 50 =0.012μg/ μL), butylated hydroxyanisole (IC 50 =0.016μg/ μL) and Trolox (IC 50 =0.013 μg/ μL). The ethanolic extract of the bark of the trunk of Pteleopsis suberosa showed bactericidal activity against the Staphylococcus aureus strain.

Progress in the Synthesis Process and Electrocatalytic Application of MXene Materials.

With their rich surface chemistry, high electrical conductivity, variable bandgap, and thermal stability, 2D materials have been developed for effective electrochemical energy conversion systems over the past decade. Due to the diversity brought about by the use of transition metals and C/N pairings, the 2D material MXene has found excellent applications in many fields. Among the various applications, many breakthroughs have been made in electrocatalytic applications. Nevertheless, related studies on topics such as the factors affecting the material properties and safer and greener preparation methods have not been reported in detail. Therefore, in this paper, we review the relevant preparation methods of MXene and the safer, more environmentally friendly preparation techniques in detail, and summarize the progress of research on MXene-based materials as highly efficient electrocatalysts in the electrocatalytic field of hydrogen precipitation reaction, nitrogen reduction reaction, oxygen precipitation reaction, oxygen reduction reaction, and carbon dioxide reduction reaction. We also discuss the technology related to MXene materials for hydrogen storage. The main challenges and opportunities for MXene-based materials, which constitute a platform for next-generation electrocatalysis in basic research and practical applications, are highlighted. This paper aims to promote the further development of MXenes and related materials for electrocatalytic applications.

ZIF-67 derived LaCoO3/Co3O4 nanoparticles/g-C3N4 P-N junction with enhanced photodynamic antibacterial performance

The escalating misuse of antibiotics has drastically reduced the availability of effective antimicrobial agents. Thus, necessitating comprehensive research and development efforts to address the challenges posed by drug-resistant bacteria and superbugs. ZIF-67 was synthesized by a simple precipitation reaction, then it was modified by La3+ etching (La3+/ZIF-67) and derived into LaCoO3/Co3O4 by one-step calcination. Subsequently, LaCoO3/Co3O4/g-C3N4 P-N junction nanocomposites with visible light-enhanced antimicrobial properties were successfully prepared by compounding LaCoO3/Co3O4 nanocomposites and the nonmetallic semiconductor g-C3N4 via wet impregnation method. Compared with LaCoO3/Co3O4, LaCoO3/Co3O4/g-C3N4 nanocomposites exhibited stronger carrier transport, separation efficiency and excellent antibacterial properties. The Minimum Inhibitory Concentrations (MICs) of LaCoO3/Co3O4/g-C3N4 nanocomposites against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were measured to be 0.8 mg·mL−1 and 0.9 mg·mL−1, correspondingly. The nanocomposites exhibited 99.64 % and 95.66 % antibacterial efficiency against the above bacteria under visible light irradiation, respectively. In addition, the positive electrical property of LaCoO3/Co3O4/g-C3N4 nanocomposites (+4.84 mV) facilitates the adequate contact between nanocomposites and bacteria, which greatly shortens the ROS transport pathway. The GSH oxidation simulating the internal metabolism of bacteria revealed that the LaCoO3/Co3O4/g-C3N4 nanocomposites were able to disrupt the antioxidant defense system of bacteria, which eventually led to bacterial apoptosis.

Multifunctional, Hybrid Materials Design via Spray-Drying: Much more than Just Drying.

Spray-drying is a popular and well-known "drying tool" for engineers. This perspectivehighlights that, beyond this application, spray-drying is a very interesting and powerful tool for materials chemists to enable the design of multifunctional and hybrid materials. Upon spray-drying, the confined space of a liquid droplet is narrowed down, and its ingredients are forced together upon "falling dry." As detailed in this article, this enables the following material formation strategies either individually or even in combination: nanoparticles and/or molecules can be assembled; precipitation reactions as well as chemical syntheses can be performed; and templated materials can be designed. Beyond this, fragile moieties can be processed, or "precursor materials" be prepared. Post-treatment of spray-dried objects eventually enables the next level in the design of complex materials. Using spray-drying to design (particulate) materials comes with many advantages-but also with many challenges-all of which are outlined here.It isbelieved that multifunctional, hybrid materials, made via spray-drying, enable very unique property combinations that are particularly highly promising in myriad applications-of which catalysis, diagnostics, purification, storage, and information are highlighted.

Capsular polysaccharide determines the serotyping of Riemerella anatipestifer.

Riemerella anatipestifer (R. anatipestifer) is a Gram-negative pathogen that causes significant economic losses to the farming industry. The polysaccharides that determine serotype are well understood in other bacteria; they have not yet been fully characterized in R. anatipestifer. In this study, we unexpectedly discovered a strain, RCAD0392, that is capable of cross-agglutination. Whole genome sequencing revealed base mutations disrupting a gene on its capsular polysaccharide synthesis gene cluster. By constructing homologous gene deletion mutants in CH-2, we demonstrated that deletion of this gene leads to altered serological phenotypes. India ink and transmission electron microscopy experiments revealed the disappearance of capsule on the surface of the bacteria, indicating the association of the gene with capsule synthesis. In addition, agar-gel precipitin tests showed that lipopolysaccharide binds to antisera of multiple serotypes, while the capsular polysaccharide only binds to the corresponding antisera. This suggests that capsular polysaccharide is the specific antigen that determines the serotype of R. anatipestifer. IMPORTANCE Riemerella anatipestifer (R. anatipestifer) is one of the most important veterinary pathogens with at least 21 serotypes. However, the exact polysaccharide(s) that determine R. anatipestifer serotype is still unknown. This study has provided a preliminary exploration of the relationship between capsular polysaccharides and serotyping in R. anatipestifer and suggests possible directions for further investigation of the genetic basis of serotypes in this bacterium.

Microwave synthesis of self-supported Bi/NF anodes with ultra-high capacity for supercapacitors and hydrogen evolution reaction

Bi nanoflakes on Ni foam (NF) for supercapacitors (SCs) are prepared by simple one-step microwave irradiation without further calcination. XRD and XPS results reveal the successful synthesis of Bi crystal. SEM and EDS results uncover the growth of Bi and the constituent elements of the complexes. The Bi anode on NF (Bi/NF) not only enables an ultra-large specific capacity of 4651 F g−1 (1 A g−1) and a capacity maintenance rate of 75% (after 1000 cycles), but it also exhibits outstanding catalytic hydrogen precipitation reaction, reaching an overpotential of −136 mV versus the reversible hydrogen electrode at −10 mA cm−2 and Tafel slope of 114.4 mV dec−1. The Bi anode is gathered into the asymmetric SC, which demonstrates an ultra-high energy density of 125 Wh kg−1 (power density of 640 W kg−1) in an alkaline electrolyte.