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Background and Aim Methods Results Conclusion Hepatic ischemia–reperfusion (I/R) injury is the primary cause of liver dysfunction and liver failure, commonly occurring in liver transplantation, hepatectomy, and hemorrhagic shock. Polo‐like kinase 2 (PLK2), a pivotal regulator of centriole duplication, plays a crucial role in cell proliferation and injury repair. However, the function of PLK2 in hepatic I/R remains unclear.The effect of PLK2 was investigated in the mouse hepatic I/R model and the hepatocyte hypoxia‐reoxygenation (H/R) model. Liver injury was assessed by serum transaminase and hematoxylin and eosin staining. Cell apoptosis was analyzed using TUNEL analysis and immunoblotting. Inflammatory factors were evaluated by reverse transcription‐quantitative polymerase chain reaction. Mice or cultured cells during the I/R or H/R were treated by overexpressing PLK2. ROS fluorescence staining was used to assess oxidative stress injury.PLK2 was upregulated after hepatic I/R injury. Overexpressed PLK2 significantly improved liver enzyme levels and alleviated liver histological injury. Moreover, PLK2 decreased hepatocyte apoptosis and inhibited the expression of inflammatory factors in liver. Mechanistically, PLK2 increased the phosphorylation of GSK3β and enhanced expression of the antioxidant enzyme HO‐1, leading to less ROS production. Inhibition of the HO‐1 aggravated ROS generation and abolished the protective effect of PLK2.Overall, these findings revealed that PLK2 enhanced HO‐1 expression and reduced oxidative stress damage in hepatic I/R injury, and this protective effect related to GSK3β activity. [ABSTRACT FROM AUTHOR]

Abstract: Hollow structures are attracting increasing attention due to their unique properties and potential applications in many fields. Despite the great successes achieved in the synthesis of hollow spheres, the preparation of nonspherical hollow structures still remains a great challenge. In this paper, we developed a facile method to prepare hematite hollow structures with cocoon-like shape. The as-prepared hematite nanococoons were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). Such cocoon-like structures are with a uniform diameter of 18nm, length of 90nm, and shell thickness of 5nm. Furthermore, the as-prepared sample exhibited high visible-light photocatalytic activity for the degradation of methyl orange due to their special hollow structure. [Copyright &y& Elsevier]

Aqueous Zn batteries, which use metallic Zn as anodes, have gained significant attention due to their affordability and high safety standards. However, these Zn anodes are plagued by issues such as Zn dendritic growth and side reactions, including corrosion and hydrogen evolution. One straightforward yet effective approach to mitigate these issues is to apply protective coatings to the Zn anodes to enhance their reversibility. It is generally believed that these protective layers should have a high affinity for Zn. Contrarily, this study proposes that non‐conductive coatings should form a strong binding with H+ ions while maintaining a weaker interaction with Zn2+ ions, thereby ensuring a higher selectivity for H+ over Zn2+. This concept is illustrated using zirconium dioxide (ZrO2), an ionic conductor that meets these criteria and effectively curbs side reactions and dendritic growth of Zn. Remarkably, Zn anodes coated with ZrO2 layer demonstrate a lifespan exceeding 6000 h at 1 mA cm−2 and 1 mAh cm−2, significantly outperforming uncoated ones, which last <200 h. This discovery introduces a novel design principle for insulating surface coatings, potentially applicable not only for Zn but also for other metal anodes. [ABSTRACT FROM AUTHOR]

We propose an acid-alkaline furfural hybrid battery that can achieve a discharging power density of 47 mW cm−2 under 100 mA cm−2 energy output with a H2 faradaic efficiency (FE) up to ca. 200% and a furoate FE of around 97% with the aid of our developed Pt–Cu electrocatalyst. [ABSTRACT FROM AUTHOR]

Developing high-efficiency electrode materials is of great importance in manufacturing supercapacitor devices with superior electrochemical performance. Herein, we for the first time report a binder-free method for controllable growth of Cu3N electrode materials via magnetron sputtering for supercapacitor applications. Benefiting from their unique polyhedral structure and good electrical conductivity, Cu3N electrodes can achieve an areal capacity of 90.7 mC cm−2 at 1 mA cm−2 and outstanding cycling stability with a capacity retention of 97.4% after 20 000 cycles. In particular, the assembled Cu3N//active carbon quasi-solid-state asymmetric supercapacitor can exhibit a maximum energy density of 13.2 μW h cm−2 and a power density of 4.8 mW cm−2 with an operating voltage of 1.6 V. These remarkable performances demonstrate the great potential of sputtered Cu3N electrode materials for future energy storage applications. [ABSTRACT FROM AUTHOR]

The traditional technologies for industrial and agricultural effluent treatment are often energy‐intensive. Herein, we suggest an electrochemical redox strategy for spontaneous and simultaneous decontamination of wastewater and generation of both fuels and electricity at low cost. Using hydrazine and nitrate effluents as a demonstration, we propose a hydrazine‐nitrate flow battery (HNFB) that can efficiently purify the wastewater and meanwhile generate both ammonia fuel and electricity with the assistance of our developed bimetallic RuCo precatalyst. Specifically, the battery delivers a peak power density of 12 mW cm−2 and continuously operates for 20 h with an ammonia yield rate of ca. 0.38 mmol h−1 cm−2 under 100 mA cm−2. The generated electricity can further drive a hydrazine electrolyzer to produce hydrogen fuel. Our work provides an alternative pathway to purify wastewater and generate high value‐added fuels at low cost. [ABSTRACT FROM AUTHOR]

The traditional technologies for industrial and agricultural effluent treatment are often energy‐intensive. Herein, we suggest an electrochemical redox strategy for spontaneous and simultaneous decontamination of wastewater and generation of both fuels and electricity at low cost. Using hydrazine and nitrate effluents as a demonstration, we propose a hydrazine‐nitrate flow battery (HNFB) that can efficiently purify the wastewater and meanwhile generate both ammonia fuel and electricity with the assistance of our developed bimetallic RuCo precatalyst. Specifically, the battery delivers a peak power density of 12 mW cm−2 and continuously operates for 20 h with an ammonia yield rate of ca. 0.38 mmol h−1 cm−2 under 100 mA cm−2. The generated electricity can further drive a hydrazine electrolyzer to produce hydrogen fuel. Our work provides an alternative pathway to purify wastewater and generate high value‐added fuels at low cost. [ABSTRACT FROM AUTHOR]

Herein we report the control synthesis of lepidocrocite VOOH hollow nanospheres and further their applications in electrocatalytic water splitting for the first time. By tuning the surface area of the nanospheres, the optimal performance can be achieved with low overpotentials of 270 mV for the oxygen evolution reaction (OER) and 164 mV for the hydrogen evolution reaction (HER) at 10 mA cm−2 in 1 m KOH, respectively. Furthermore, when used as both the anode and cathode for overall water splitting, a low cell voltage of 1.62 V is required to reach the current density of 10 mA cm−2, making the VOOH hollow nanospheres an efficient alternative to water splitting. [ABSTRACT FROM AUTHOR]

Electricity-driven proton exchange membrane water electrolyzers are a promising technology to produce dihydrogen gas (H2). However, this technology is limited by the anodic oxygen evolution reaction that controls the overall operation efficiency, since only few electrocatalysts are efficient under the strongly acidic and oxidative conditions. Accordingly, there is a need for electrocatalysts with high activity, high stability, and low cost for the reaction of acidic oxygen evolution. Here, we review electrocatalysis using the acidic oxygen evolution reaction. We discuss two mechanisms of the oxygen evolution reaction: the adsorbate evolution mechanism and the lattice oxygen mechanism. We then summarize strategies to improve the performance of electrocatalysts by active site engineering, electron distribution optimization, interaction modulation, vacancy engineering, and lattice strain regulation. Challenges include the understanding of mechanisms of the oxygen evolution reaction, the operation durability at industrial currents, the flow reactor design of proton exchange membrane water electrolyzers, the alternative reactions, the development of nonprecious metal-based electrocatalysts, and large-scale synthetic approaches of electrocatalysts. Finally, precautions for electrochemical tests are proposed. [ABSTRACT FROM AUTHOR]

Water electrolysis is regarded as an efficient and green method to produce hydrogen gas, a clean energy carrier that holds the key to solving global energy problems. So far, the efficiency and large‐scale application of water electrolysis are restricted by the electrocatalytic activity of applied catalysts. Recently, the reconstruction phenomenon of electrocatalysts during a catalytic reaction has been discovered, which could form reactive sites for both the oxygen evolution and hydrogen evolution reactions. Regulation of the reconstruction process to generate a large number of reactive species with high activity has since been demonstrated as an effective strategy to enhance the catalytic performance of electrocatalysts. This review summarizes recent progress in the regulation strategies for reconstruction reactions. First, the mechanism of water electrolysis is briefly introduced, and the critical factors regarding the reconstruction process are systematically discussed, followed by a brief introduction of advanced characterization for reconstruction. Moreover, the modulation strategies are summarized with reported examples highlighting the promoted effects on the reconstruction process. Finally, the challenges facing surface‐reconstructed catalysts for water electrolysis in the future are discussed. [ABSTRACT FROM AUTHOR]

Flexible zinc ion batteries are a promising energy supply for flexible and wearable electronic devices due to their high theoretical capacity, superior safety, low cost, and eco-friendliness. The rational design of highly efficient flexible zinc ion batteries with high electrochemical performance, long cycling life, and excellent mechanical deformability is still a formidable challenge, limiting their widespread application in flexible electronics. This paper summarizes the recent progress in designing and fabricating flexible zinc ion batteries from three aspects: device configurations, battery constituent components, and practical applications. First, we introduce the energy storage mechanism and summarize modification strategies of constituent components, including current collector, zinc anode, cathode, and solid/gel electrolyte, revealing their positive effects on the performance of flexible zinc ion batteries. Then, we elucidate advanced device configurations for flexible zinc ion batteries such as sandwich-type, planar, and fiber-type structures, followed by discussion on the specific properties of flexible zinc ion batteries that enhance their adaptability in practical applications, such as integration with electronics, self-healing ability, resistance to extreme conditions, and responsiveness to environments. The current challenges and outlooks are also presented. [ABSTRACT FROM AUTHOR]

Highlights: [•] MnFe2O4/chitosan nanocomposites were synthesized by a simple method. [•] The material was used to remove Cr(VI) in low concentration solution. [•] Effective removal of Cr(VI) from aqueous solution. [Copyright &y& Elsevier]

Abstract: Hierarchically 3D flower-like α-Fe2O3 microstructures have been synthesized through a urea-assisted hydrothermal synthetic route. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The as-prepared product was consisted of hierarchically flow-like microstructures assembled from nanopetal subunits. The effects of the urea and NaOH on the morphology of the products were systematically studied, and a possible formation mechanism of the α-Fe2O3 microflowers was proposed based on the experimental results. These flower-like α-Fe2O3 microstructures were used as adsorbent for water treatment, and the results revealed excellent performance for heavy metal ion removal. With maximum capacities of 41.46 and 33.82 mg g−1 for As(V) and Cr(VI), respectively, such flower-like α-Fe2O3 microstructures are expected to be an attractive adsorbent for the removal of heavy metal ions from water. [Copyright &y& Elsevier]

The article focuses on the use of irradiation precuring and oxidation curing in the rapid preparation of silicon carbide fibers. It states that polycarbosilane with a low melting point is used to reduce the difficulty in melt-spinning of silicon carbide fibers. It mentions that the use of electron beam irradiation at low dosage raises the melting point of the polycarbosilane which allows the fibers to be cured quickly without fusion. It comments that the reduction of silicon-hydrogen bonds and the formation of silicon-carbon cross-linkage helps increase the efficiency of subsequent oxidation.

Titanium (Ti) and its alloys have been extensively used as implant materials in clinical practice due to their high corrosion resistance, light weight and excellent biocompatibility. However, the insufficient intrinsic osteogenic capacity of Ti and its alloys impedes bone repair and regeneration, and implant-related infection or inflammation remains the leading cause of implant failure. Bacterial infections or inflammatory diseases constitute severe threats to human health. The physicochemical properties of the material are critical to the success of clinical procedures, and the doping of Cu into Ti implants has been confirmed to be capable of enhancing the bone repair/regeneration, angiogenesis and antibacterial capability. This review outlines the recent advances in the design and preparation of Cu-doped Ti and Ti alloy implants, with a special focus on various methods, including plasma immersion implantation, magnetron sputtering, galvanic deposition, microarc oxidation and sol-gel synthesis. More importantly, the antibacterial and mechanical properties as well as the corrosion resistance and biocompatibility of Cu-doped Ti implants from different methods are systematically reviewed, and their prospects and limitations are also discussed. [ABSTRACT FROM AUTHOR]

The sustainable development of catalysts with Pt-like catalytic activity to produce hydrogen economically from water electrolysis is essential and challenging. Herein, we have prepared a novel catalyst with the combined virtues of nanocolumn structures and heterojunctions by magnetron sputtering molybdenum nitride (Mo 2 N) thin films over cobalt-metal-organic framework (Co-MOF) nanocolumns on carbon paper (CP), and explored the catalytic activities in hydrogen evolution reaction (HER). By optimizing the preparation process, the heterostructured Co-MOF@Mo 2 N/CP catalysts can exhibit an excellent HER performance with an overpotential of only 72.8 mV at 10 mA cm−2 and cycling durability over 24 h and 5000 cycles, achieving one of the best performances among state-of-the-art Mo-based catalysts. This work guides and accelerates the design of low-cost and high-performance transition metal nitrides HER catalysts for industrial applications. • Heterostructured Co-MOF@Mo 2 N/CP nanocolumns were fabricated by self-assembly and magnetron sputtering. • Effects of reaction and sputtering times on microstructure and HER properties were studied. • Co-MOF@Mo 2 N/CP catalyst exhibits excellent HER activity and durability. [ABSTRACT FROM AUTHOR]

In the article "Design Principle of Insulating Surface Protective Layers for Metallic Zn Anodes: A Case Study of ZrO2," the authors present a design principle for non-conductive coatings that protect Zn anodes in aqueous Zn batteries. These coatings should have a strong binding with H+ ions and a weak binding with Zn2+ ions. The authors use the analogy of a stargate, where the coatings act as a barrier, allowing only "Zn" spaceships while blocking "H" spaceships. This research provides valuable insights for the development of more efficient and durable batteries. [Extracted from the article]

Suitable electrode materials play a decisive role in the performance of supercapacitors. In recent years, transition metal nitrides come into view because of their advantages of superior electrical conductivity exceeding the corresponding metal oxides and higher specific capacitance compared with carbon-based materials. Herein, we have successfully synthesized the binder-free Co 3 N thin films for high-efficiency supercapacitor by reactive magnetron sputtering. Remarkedly, the Co 3 N thin film electrodes can reach a high specific capacity of 47.5 mC cm−2 at a current density of 1.0 mA cm−2 along with reasonable cycling stability (78.1% remaining after 10,000 cycles). These findings have proved that the Co 3 N thin films have great potential applications for supercapacitors or other electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Transition metal nitrides (TMNs) are rapidly gaining prominence as attractive supercapacitor electrode materials due to their intriguing properties. Nevertheless, the quest for facile and green fabrication of TMNs electrodes with high supercapacitor performance remains a substantial challenge. In this study, we have successfully designed and prepared the binder-free V-doped CrN thin film electrodes through a one-step reactive magnetron co-sputtering in nitrogen and argon atmosphere without high temperature heating. Our experimental and DFT findings confirm that the V doping increases the number of active sites, enlarges the specific surface area, and enhances the electron concentration and electrical conductivity. Consequently, the CrVN thin film electrodes achieve a remarkable specific capacitance of 22.8 mF cm−2 at 1.0 mA cm−2, along with excellent cycling performance (93.9% capacitance retention after 20,000 cycles at 5.0 mA cm−2). Furthermore, the assembled CrVN symmetric supercapacitor device exhibits a substantial energy density of 11.2 mWh cm−3 and an impressive power density of 7.5 W cm−3, respectively. These encouraging outcomes open new avenues for developing ternary TMNs-based electrodes for high performance supercapacitors. • Fabricate binder-free CrVN thin film electrodes by one-step magnetron co-puttering. • CrVN electrode achieves a remarkable specific capacitance and cycling durability. • Explore the superior supercapacitive performance by experiments and DFT calculations [ABSTRACT FROM AUTHOR]

Transition metal nitrides become promising electrode materials for supercapacitors due to high chemical stability and electrical conductivity. This study reports a facile (one step) and green (mixed atmosphere of argon and nitrogen without any external heating) strategy for fabricating nanostructured porous transition metal nitride thin films by oblique angle magnetron sputtering and their applications as binder-free electrode materials for symmetric supercapacitors. Using CrN as a demonstration, the thin film electrode shows a high specific capacitance of 17.7 mF cm−2 at a current density of 1.0 mA cm−2, exceeding most of previously reported transition metal nitrides by normal magnetron sputtering. Furthermore, a symmetric supercapacitor device based on nanostructured porous CrN thin film can deliver maximum energy and power densities of 7.4 mWh cm−3 and 18.2 W cm−3 respectively, along with good cycling stability (92.2% capacitance retention after 20000 cycles at a current density of 2.0 mA cm−2). Specially, the oblique angle magnetron sputtering can serve as a versatile route to fabricate nanostructured porous transition metal nitrides for electrochemical energy storage and conversion. Image 1 • Nanostructured porous CrN were deposited by oblique angle magnetron sputtering. • High specific capacitance correlates with porous nanostructure and lattice defects. • A symmetric supercapacitor delivers both high energy density and power density. • This technique can fabricate other nanostructured porous transition metal nitrides. [ABSTRACT FROM AUTHOR]

In this work, we introduce for the first time an aqueous solution method followed by a selenization step to prepare Mn-doped CoSe2 nanosheets supported on nickel foam for the oxygen evolution reaction. These findings provide us highly efficient electrocatalysts instead of noble metal catalysts for the oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Abstract The rational design of highly efficient electrocatalysts to generate hydrogen by catalyzing hydrogen evolution reaction still remains a challenge. Herein, we report a simple strategy to significantly enhance the catalytic activities of NiCo 2 O 4 nanowire arrays by simply tuning the amount of oxygen vacancies. Remarkably, the oxygen-deficient NiCo 2 O 4 catalysts obtained in Ar environment show significantly improved catalytic activities toward hydrogen evolution reaction with the requirement of 104 mV overpotential to afford 10 mA cm−2, 122 mV less than that for air-sintered NiCo 2 O 4 (226 mV). Moreover, such catalysts also exhibit superior long-term durability for 24 h at 100 mA cm−2. The present study further promotes the application of NiCo 2 O 4 in other energy storage and conversion system. Highlights • NiCo 2 O 4 nanowire arrays with rich oxygen deficiencies are prepared toward HER. • Oxygen deficient structure can provide more active sites and boost HER performance. • The NiCo 2 O 4 catalysts require a low overpotential of 104 mV to reach 10 mA cm−2. • The NiCo 2 O 4 catalysts exhibit long-term durability over 24 h at 100 mA cm−2. [ABSTRACT FROM AUTHOR]

We report the preparation of 3D binder-free Si@Ti@TiN thin film array electrodes for supercapacitors using deep silicon etching and magnetron sputtering for the first time. This work not only offers the 3D array structure of Si@Ti@TiN thin films, but also paves a promising way for the construction of high-energy storage systems. [ABSTRACT FROM AUTHOR]

Abstract In this work, we systematically investigate and compare the activity of MnCo-based electrocatalysts (i.e. selenide, oxide, and hydroxide) for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solutions. The result indicates that the selenides are oxidized upon OER and the surface generated oxides are the real OER active species. The MnCo selenides exhibit a significantly enhanced performance as compared to the oxide and hydroxide though the real active OER species of these three catalysts are essentially the same. The superior activity of MnCo selenides could be attributed to the high intrinsic conductivity and the high surface active area. Further, the synergy between Mn and Co lowers the energy barrier for catalysis and helps to stabilize the material. The bimetallic MnCo selenides with yolk shell structures possess the optimal electrochemical performance with a low cell voltage of 1.66 V at the current density of 50 mA cm−2, outperforming most of the earth-abundant electrocatalysts. Our work provides a better understanding of the active species of metal selenides and the origin of the performance disparity between selenides (-derived oxides) and oxides electrocatalysts. Graphical abstract Image 1 Highlights • The electrolyzer with both Mn-Co-Se electrodes drives 50 mA cm−2 at a cell voltage of 1.66 V. • Almost 100% Faradaic efficiency of HER and OER is achieved. • The surface generated oxides are the real active species of selenides for OER. • The synergy between Mn and Co lowers the energy barrier for catalysis and stabilizes the material. [ABSTRACT FROM AUTHOR]

Selecting suitable electrode materials is the key to develop high-performance supercapacitors. Herein, we report the niobium nitride (NbN) thin films prepared by reactive magnetron sputtering and investigate their electrochemical performances when used as supercapacitor electrodes. NbN thin film electrodes can achieve the optimal electrochemical performance with a volumetric capacitance of 707.1 F cm −3 and an outstanding cycling stability (remaining 92.2% after 20,000 cycles). Such impressive properties render the NbN thin films qualified as the promising candidates for supercapacitors or other energy storage systems. [ABSTRACT FROM AUTHOR]

Developing advanced materials with high catalytic activity for electrocatalytic applications is of vital importance to mitigate the energy crisis. In this work, we for the first time report a novel method to prepare bimetallic vanadium‑molybdenum nitride (MoVN) thin films by magnetron co-sputtering and further demonstrate their applications for hydrogen evolution reaction (HER). When used as HER catalysts, the resulting MoVN thin film electrodes show superior electrocatalytic activity especially in alkaline electrolyte in contrast to bare VN and Mo 2 N, delivering a low overpotential of 108 mV to afford a current density of 10 mA cm −2 , a Tafel slope of 60 mV dec −1 , as well as excellent long-term durability. Most importantly, our study opens opportunities to explore new HER catalyst materials in the family of bimetallic transition metal nitrides. [ABSTRACT FROM AUTHOR]

Both high corrosion resistance and electrical conductivity are required for the surface coatings of the magnesium alloys as used in electronics or aerospace applications. In this study, anticorrosive yet conductive Hf/HfN multilayer coatings are deposited on magnesium alloys via magnetron sputtering. The microstructural characterizations reveal that the growth of nano-scale pinholes along with the columnar structure of Hf sublayers have been completely suppressed by introducing the nanocrystalline HfN sublayers. The optimized Hf/HfN multilayer coated magnesium alloy exhibits a positive corrosion potential of − 0.51 V vs SCE and low corrosion current density of 0.01 μA/cm 2 in electrochemical system, and few corrosion pits after 48 h salt spray test, while maintaining the fine electronic conductivity similar to magnesium alloy. The desirable performance was attributed to the multilayer structure induced by nanocrystalline HfN interlayer, which resulted in decreased coating porosity, confined pathway and increased energy barrier for corrosion media. [ABSTRACT FROM AUTHOR]

Transition metal nitrides are regarded as a new class of excellent electrode materials for high-performance supercapacitors due to their superior chemical stability and excellent electrical conductivity. We synthesize successfully the porous CrN thin films for binder-free supercapacitor electrodes by reactive magnetron co-sputtering and selective chemical etching. The porous CrN thin film electrodes exhibit high-capacitance performance (31.3 mF cm −2 at 1.0 mA cm −2 ) and reasonable cycling stability (94% retention after 20000 cycles). Moreover, the specific capacitance is more than two-fold higher than that of the CrN thin film electrodes in previous work. In addition, a symmetric supercapacitor device with a maximum energy density of 14.4 mWh cm −3 and a maximum power density of 6.6 W cm −3 is achieved. These findings demonstrate that the porous CrN thin films will have potential applications in supercapacitors. [ABSTRACT FROM AUTHOR]

A novel and bifunctional hafnium/poly (l, l-lactide) duplex coating (Hf/PLLA) was fabricated on magnesium alloy via magnetron sputtering coupled with dip-coating method. Microstructure, composition, in vitro degradation and cytocompatibility of coating were examined systematically. The in vitro electrochemical tests revealed that the Hf/PLLA duplex coating has significantly suppressed the degradation of magnesium alloy with the low corrosion current density of 0.02 μA/cm 2 and high corrosion resistance of 324.5 KΩ cm 2 . Simultaneously, the cytocompatibility of magnesium alloy was further improved, as observed by the superior cell adhesion and proliferation of human osteoblast-like MG63 cells on the duplex coating. [ABSTRACT FROM AUTHOR]

In this study, the CrN x coatings were deposited by reactive magnetron sputtering at varying sputtering power from 200 to 300 W. The chemical composition, phase structure, surface and cross-sectional morphologies, and mechanical properties of the coatings were respectively investigated by electron probe microanalysis, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopy, and nano-indentation measurements. The results show that the coating deposited at a sputtering power of 200 W is a single-phase fcc CrN with columnar structure, while the coatings deposited at sputtering powers of 250 and 300 W are consisted of hexagonal Cr 2 N and fcc CrN with nano-composite structure. As compared with the single-phase Cr 2 N or CrN coatings, the composite coatings exhibit both higher hardness and superior resistance to plastic deformation and cracking, which is attributed to their unique nano-composite structure. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate that the electrocatalytic activity of transition metal chalcogenides can be greatly enhanced by simultaneously engineering the active sites, surface area, and conductivity. Using metal-organic frameworks-derived (Ni,Co)Se 2 /C hollow rhombic dodecahedra (HRD) as a demonstration, we show that the incorporation of Ni into CoSe 2 could generates additional active sites, the hierarchical hollow structure promotes the electrolyte diffusion, the in-situ hybridization with C improves the conductivity. As a result, the (Ni,Co)Se 2 /C HRD exhibit superior performance toward the overall water-splitting electrocatalysis in 1 M KOH with a cell voltage as low as 1.58 V at the current density of 10 mA cm −2 , making the (Ni,Co)Se 2 /C HRD as a promising alternative to noble metal catalysts for water splitting. [ABSTRACT FROM AUTHOR]

Low temperature thermal oxidation treatment is performed on the PVD (physical vapor deposition) hafnium-coated magnesium alloy. The results indicate that thin hafnium oxide film and new shallow grain boundaries were appeared on the coating surface. Surface oxidation and densification of the coating induced by the post treatment significantly decreased its susceptibility to corrosion. Moreover, the release of the residual stress produces a positive effect on suppressing the delaminating of the coating as magnesium is corroded. Consequently, the treated coating exhibits more positive corrosion potential, lower corrosion current density and higher polarization resistance than that of the untreated coating in Hanks’ solution. Salt spray test further reveals that the post-treated hafnium coating can provide a longer-term and more efficient protection for magnesium alloy. [ABSTRACT FROM AUTHOR]

Hafnium monolayer and Hf/Si 3 N 4 multilayer coatings were deposited on AZ91D magnesium alloys via magnetron sputtering. The microstructure, conductivity and corrosion behaviors of these coatings were investigated. It was found that the columnar growth of the Hf sublayer was suppressed in the Hf/Si 3 N 4 multilayer coating. This multilayered structure resulted in the relief of residual stress and the decrease in porosity. These changes in microstructure inhibited the permeation of corrosion media into the substrate and decreased the diffusion rates of corrosion products. The Hf/Si3N4 multilayer coatings with 10 bilayers showed the best anticorrosion performance revealed by the lowest corrosion current density of 2.798 μA/cm 2 in electrochemical system and the smallest corrosion area of 0.22% after 48 h salt spray test, respectively. Additionally, the introduction of Si 3 N 4 sublayer has little impact on the conductivity of the multilayer coating due to the shadowing effect during the deposition. [ABSTRACT FROM AUTHOR]

Herein we report the control synthesis of lepidocrocite VOOH hollow nanospheres and further their applications in electrocatalytic water splitting for the first time. By tuning the surface area of the nanospheres, the optimal performance can be achieved with low overpotentials of 270 mV for the oxygen evolution reaction (OER) and 164 mV for the hydrogen evolution reaction (HER) at 10 mA cm−2 in 1 m KOH, respectively. Furthermore, when used as both the anode and cathode for overall water splitting, a low cell voltage of 1.62 V is required to reach the current density of 10 mA cm−2, making the VOOH hollow nanospheres an efficient alternative to water splitting. [ABSTRACT FROM AUTHOR]

This paper focuses on the deposition of anti-corrosion, conductive coatings for Mg alloys used in electronics and aerospace industries. Metallic Al, Ti, Zr and Hf coatings were fabricated on an AZ91D Mg alloy surface via magnetron sputtering. Electrochemical system and salt spray tests were performed to investigate the corrosion resistance and the mechanism of corrosion failure of coated samples. The Hf-coated Mg alloy exhibited an extremely low corrosion current density of 0.825 μA/cm 2 and a high protective efficiency of 99.49% during the electrochemical test. More importantly, the Hf coating provided superior protection for the Mg alloy against corrosion during the 24 h salt spray test. However, the Al-, Ti- and Zr-coated alloys exhibit poor performances in the above measurements. The low difference in potentials, the excellent corrosion resistance and the good adhesion to the substrate are considered probable causes for the anti-corrosion performance of the Hf coating. [ABSTRACT FROM AUTHOR]

A three-dimensional porous hybrid aerogel assembly of Bi 2 WO 6 nanosheets and graphene has been prepared by a facile solvothermal route. The products are characterized by X-ray diffraction, Scanning electron microscope, Transmission electron microscopy, and so on. The results show the highly interconnected and porous network microstructure stacked by graphene and Bi 2 WO 6 nanosheets in the hybrid aerogel. The specific surface area of hybrid aerogel (39.4 m 2 g −1 ) is 1.6 times higher than that of Bi 2 WO 6 nanosheets. The Rhodamine B removal ratio over the composite aerogel reaches up to 99.6% within 45 min, which is higher than that of pure Bi 2 WO 6 nansosheets (80%). The excellent photocatalytic performance is mainly owing to the porous structure of aerogel and high electrical conductivity of graphene. The study on the photocatalytic mechanism demonstrates that O 2 − • is the main reactive species for Rhodamine B degradation. [ABSTRACT FROM AUTHOR]

Mechanical properties and oxidation resistance are of importance for the NbN x coatings as used in cutting and forming tools. In this study, the NbN x coatings were deposited by magnetron sputtering at nitrogen partial pressure ranging from 0 to 40%. The chemical and phase compositions, morphologies, mechanical properties and oxidation behaviors of the NbN x coatings were investigated by electron probe microanalysis, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, scanning and transmission electron microscopy, and nanoindentation measurements. The results reveal the composition evolution of the NbN x coatings as α-Nb (0%), β-Nb 2 N (5%), a mixture of β-Nb 2 N and δ-NbN (10%), and δ-NbN (20–40%). The single phase coatings exhibit columnar structure while the mixed phases coating shows nano-composite structure. Compared with the single phase δ-NbN coatings (21.6 ± 0.8–28.0 ± 1.2 GPa), higher hardness of the single phase β-Nb 2 N coating (30.9 ± 1.0 GPa) is due to the higher covalent character and much finer grains. The maximum hardness reaches 33.3 ± 1.5 GPa for the nano-composite coating with mixed phases of β-Nb 2 N and δ-NbN. The oxidation results demonstrate that the activation energies are 219.3 and 192.3 kJ/mol for the Nb 2 N and NbN coatings respectively. Non-protective Nb 2 O 5 scales with cracks and pores result in poorer oxidation resistance of the NbN coating in comparison to the Nb 2 N coating. [ABSTRACT FROM AUTHOR]

Hexagonal LaCO 3 OH with layer-tunable microstructures have been synthesized by a facile hydrothermal method. Typically, two-dimensional (2D) LaCO 3 OH microplates and three-dimensional (3D) layer-by-layer (LBL) LaCO 3 OH were produced by simply adjusting the experimental parameters. In the synthetic procedure, the volume of carbon disulfide (CS 2 ) added to the reaction mixture was found to be crucial in the formation of the layer-tunable microstructures. A possible formation mechanism of the LBL LaCO 3 OH has been also proposed from a temporal evaluation of the products. Furthermore, photoluminescence (PL) study demonstrated that the LBL LaCO 3 OH emitted stronger fluorescence than the single layer microplates. [ABSTRACT FROM AUTHOR]

A series of coral-like Co-doped ZnS were synthesized by hydrothermal method and used for efficient photodegradation of methylene blue. The chemical composition and microstructure of the Co-doped ZnS were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectra, scanning electron microscope, and transmission electron microscopy. The results showed that the Co atoms were incorporated into the Zn-S lattice, forming solid solution-type phase. As the Co dopant concentration increases from 0 to 22.49 at.%, the calculated band gap energy of the doped ZnS decreases from 3.32 to 2.65 eV, which enables stronger absorption of visible light. Furthermore, the Co dopant could act as electron trapping center, which inhibits the recombination of the photoinduced electrons and holes. As such, the Co-doped ZnS micro-corals showed higher photodegradation efficiency for methylene blue compared with pristine ZnS. The optimized photocatalytic activity was achieved on 5.49 at.% Co-doped ZnS. [ABSTRACT FROM AUTHOR]

In this article, Cu 2+ and Mn 2+ are chosen as divalent metal cations to dope and synthesize Li 2 MTi 3 O 8 (M = Cu, Mn, Cu 0.5 Mn 0.5 ) by a simple solid state reaction route. The structures of Li 2 MTi 3 O 8 (M = Cu, Mn, Cu 0.5 Mn 0.5 ) are proved by Rietveld refinement method for the first time. Due to different divalent metal cations M 2+ in the structure, Li 2 MTi 3 O 8 exhibits different electrochemical performances. Li 2 CuTi 3 O 8 shows the highest initial charge capacity of 242 mAh g −1 and Li 2 MnTi 3 O 8 displays the lowest initial charge capacity of 139.5 mAh g −1 among all the three samples. Although Li 2 Cu 0.5 Mn 0.5 Ti 3 O 8 reveals a lower initial charge capacity of 174.5 mAh g −1 , it exhibits better cycle performance than Li 2 CuTi 3 O 8 and Li 2 MnTi 3 O 8 . Li 2 Cu 0.5 Mn 0.5 Ti 3 O 8 keeps the reversible capacity of 143 mAh g −1 after 50 cycles at 100 mA g −1 with capacity retention of 82.2%. Besides, the results of electrochemical impedance spectra indicate that lithium ion can move easily in the tunnels of three-dimensional network formed by the (Li 0.7 Cu 0.15 Mn 0.25 ) tet , which is in agreement with the result that Li 2 Cu 0.5 Mn 0.5 Ti 3 O 8 performs better electrochemical properties than Li 2 CuTi 3 O 8 and Li 2 MnTi 3 O 8 . It provides a possibility and theoretical support to synthesize Ti-based materials Li 2 MTi 3 O 8 with good electrochemical performances. [ABSTRACT FROM AUTHOR]

Na-doped Li 2 CoTi 3 O 8 is prepared via Li-site substitution with Na for the purpose of improving its cycle performance as an anode. Upon Na-doping, Rietveld refinement result reveals that Na takes the tetrahedral sites (8c) shared with Li and Co in the structure. Due to the larger ionic radius of Na than Li, an increased disorder degree of ion locations in the structure is induced by Na doping. Furthermore, the lithium ion diffusion tunnel is also expanded after Na doping. Galvanostatic charge/discharge tests denote that Li 1.90 Na 0.10 CoTi 3 O 8 displays better cycling property and higher reversible capacity than pristine Li 2 CoTi 3 O 8 and other Li 2−x Na x CoTi 3 O 8 materials. It can be found that Li 1.90 Na 0.10 CoTi 3 O 8 can maintain a reversible capacity of 268.9 mAh g −1 at a current density of 100 mA g −1 (0.14 C) after 50 cycles, corresponding to 90.6% of the initial charge capacity. Even cycled at a high current density of 1426 mA g −1 (2 C), Li 1.90 Na 0.10 CoTi 3 O 8 can also maintain a reversible capacity of 179.2 mAh g −1 after 80 cycles. Besides, the reversible structural changes of Na-doped Li 2 CoTi 3 O 8 are also proved by various in-situ and ex-situ observations. The significant improvements at cycling and rate performances demonstrate that Li 1.90 Na 0.10 CoTi 3 O 8 is a promising anode material for rechargeable lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Nonspherical hollow nanoparticles (NHNPs) have attracted a great deal of attention in recent years due to their unique properties and many promising applications. However, compared to hollow spheres, the fabrication of NHNPs is generally much more difficult and there are only a few successful examples to date. In this work, X-shaped hollow α-FeOOH penetration twins were first synthesized by a facile hydrothermal reaction. X-shaped α-Fe 2 O 3 hollow nanostructures with high-index { 1 1 2 ¯ 3 } facets exposed were further obtained via the topotactic transformation of α-FeOOH precursor. To the best of our knowledge, this is the first report on the nanostructures with high-index facets as well as a hollow interior. Owing to the special hollow structure and the high-energy surface, the as-obtained α-Fe 2 O 3 nanocrystals show excellent visible-light photocatalytic activity toward the degradation of RhB. [ABSTRACT FROM AUTHOR]

Keywords: electrocatalysts; hydrogen evolution reaction; oxygen evolution reaction; surface reconstruction; water electrolysis EN electrocatalysts hydrogen evolution reaction oxygen evolution reaction surface reconstruction water electrolysis 1 1 1 09/05/22 20220901 NES 220901 B Surface Reconstruction b In article number 2201713, Qiu Jiang, Hanfeng Liang and co-workers discuss the regulation strategies for surface reconstruction of electrocatalysts. Electrocatalysts, hydrogen evolution reaction, oxygen evolution reaction, surface reconstruction, water electrolysis Surface Reconstruction of Water Splitting Electrocatalysts (Adv. [Extracted from the article]

We report the controlled synthesisof NiCo layered double hydroxide(LDH) nanoplates using a newly developed high temperature high pressurehydrothermal continuous flow reactor (HCFR), which enables directgrowth onto conductive substrates in high yield and, most importantly,better control of the precursor supersaturation and, thus, nanostructuremorphology and size. The solution coordination chemistry of metal–ammoniacomplexes was utilized to synthesize well-defined NiCo LDH nanoplatesdirectly in a single step without topochemical oxidation. The as-grownNiCo LDH nanoplates exhibit a high catalytic activity toward the oxygenevolution reaction (OER). By chemically exfoliating LDH nanoplatesto thinner nanosheets, the catalytic activity can be further enhancedto yield an electrocatalytic current density of 10 mA cm–2at an overpotential of 367 mV and a Tafel slope of 40 mV dec–1. Such enhancement could be due to the increased surfacearea and more exposed active sites. X-ray photoelectron spectroscopy(XPS) suggests the exfoliation also caused some changes in electronicstructure. This work presents general strategies to controllably grownanostructures of LDH and ternary oxide/hydroxides in general andto enhance the electrocatalytic performance of layered nanostructuresby exfoliation. [ABSTRACT FROM AUTHOR]

In this work, spinel Li 2 MnTi 3 O 8 is successfully prepared by using a simple sol-gel route and evaluated as an anode material for lithium-ion batteries. Charge-discharge tests exhibits than spinel Li 2 MnTi 3 O 8 can deliver an initial discharge capacity of 273.5 mAh g −1 and the reversible capacity is kept at 206.1 mAh g −1 after 50 cycles, corresponding to 94.5% of the initial charge capacity. The electrochemical reaction mechanism between Li 2 MnTi 3 O 8 and lithium is investigated based on the results of various in-situ and ex-situ observations. The result indicates that the (Li 0.505 Mn 0.495 ) tet (Li 0.495 Mn 0.005 ) oct Ti 1.5 oct O 4 has multiple interstitials to accommodate lithium ions during the lithiation process, in which the octahedral sites (4a) would be occupied by lithium ions at high working potential and the tetrahedral sites (8c) would be occupied by lithium ions at low working potential. As a result, two two-phase transitions between three end-number phases Li 2 MnTi 3 O 8 , Li 3 MnTi 3 O 8 and Li 5 MnTi 3 O 8 can be observed during the reversible electrochemical reaction between Li 2 MnTi 3 O 8 and lithium. [ABSTRACT FROM AUTHOR]

Complex spinel Li 2 MnTi 3 O 8 is prepared by a simple solid state reaction route. Electrochemical test shows that Li 2 MnTi 3 O 8 reveals excellent electrochemical property as anode material with a reversible capacity of 193.8 mAh g −1 and corresponding capacity retention of 88.0% after 50 cycles. In-situ X-ray diffraction observation reveals that Li 2 MnTi 3 O 8 shows a quasi-reversible structural evolution during charge–discharge process. For the lithium storage process, lithium-ion initially migrates to 4a position and forms Li–O octahedron at high lithiation potential, and then lithium-ion accommodates 8c position to form Li–O tetrahedron at low lithiation potential. The reverse charge process is quasi-reversible. As a result, Li 2 MnTi 3 O 8 shows high structural stability as a promising lithium storage material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

This study investigates the influence of Y addition to the microstructure and oxidation resistance of ZrN coating. Zr–Y–N coatings with a 0–5.8 at.% Y addition were fabricated by reactive co-sputtering in an Ar–N 2 atmosphere. The results indicate that solid solution–type Zr–Y–N coatings show a columnar structure with a strong (1 1 1) preferred orientation. The grain size decreases from 76 to 21 nm with an increase in the amount of Y from 0 to 5.8 at.%. The oxidation results demonstrate that the most beneficial addition of Y to improve the oxidation resistance of ZrN coating is 1.0 at.%. An excessive addition of Y produces detrimental effects. Cracking in the oxide scale and oxygen inward diffusion through the scale have been identified as the primary reasons for the loss of oxidation resistance. [ABSTRACT FROM AUTHOR]

Highlights: [•] Li2Zn0.5Cu0.5Ti3O8 was prepared by a simple solid state reaction. [•] Li2Zn0.5Cu0.5Ti3O8 shows better electrochemical property than Li2CuTi3O8 and Li2ZnTi3O8. [•] Li2Zn0.5Cu0.5Ti3O8 can deliver a reversible capacity of 162mAhg−1 after 50 cycles. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report the hydrothermal synthesis, structural characterization and electrochemical properties of uniform α-Fe2O3 microspheres. In the synthetic procedure, the surfactant, sodium citrate, was found to be crucial to the formation of α-Fe2O3 microspheres. In addition, by simply varying the concentration of sodium citrate, cylindrical α-Fe2O3 microstructures could be readily obtained. On the basis of time-dependent experimental result, a possible formation mechanism of the α-Fe2O3 microspheres was proposed. The as-obtained α-Fe2O3 microspheres were then evaluated as an anode material for lithium ion batteries. And the result shows that the material exhibited an initial discharge capacity as high as 1453.4mAhg−1. After 50 cycles, the reversible discharge capacity was 489.5mAhg−1, which was much higher than that of commercial graphite. This work provides an additional strategy to prepare self-assembled structures with tailored morphology. And the results are helpful to further understand the mechanism of self-organization and expand the applications of iron oxide micromaterials. [Copyright &y& Elsevier]

Abstract: In this paper, α-Fe2O3 nanorings were synthesized and used as a support to further synthesize hybrid Pt/α-Fe2O3 nanorings. Transmission electron microscopy (TEM) analyses clearly suggest that Pt nanoparticles are deposited on the surface of α-Fe2O3 nanorings in a well-dispersed state. This metal–semiconductor hybrid system is expected to show high photocatalytic activity towards the degradation of environmental pollutants. Because of the Schottky contact between semiconductor and metal particles, the holes prefer to localize in energetically lower semiconductor, whereas the electrons can move through the heterointerface. This interfacial charge transfer and separation facilitate the redox reactions, results in a high photocatalytic activity. In our case, the as obtained α-Fe2O3/Pt hybrids exhibit enhanced photocatalytic performance with a degradation rate of 86.7% for methyl orange, which is much higher than that of pure α-Fe2O3 (33.2%). [Copyright &y& Elsevier]