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It is still a great challenge in preparing non-precious metal catalysts with high activity and long-term stability to substitute for precious metal catalysts for oxygen reduction reaction (ORR) in fuel cells. Herein, we report a novel and facile catalyst-N, S co-doped carbon spheres with highly dispersed CoO (CoO@NS-CSs), where biomass glucose spheres act as carbon precursor and H 2 S, NH 3 derived from the decomposition of thiourea not only provide N, S sources but also can etch carbon spheres to produce nanoporous structure. CoO@NS-CSs catalyst exhibits excellent ORR activity with a high onset potential of 0.946 V vs. RHE (reversible hydrogen electrode) and a half-wave potential of 0.821 V vs. RHE through a four-electron pathway in alkaline solution, which is comparable to commercial Pt/C catalyst (onset potential: 0.926 V vs. RHE, half-wave potential: 0.827 V vs. RHE). Furthermore, both the long-term stability and methanol-tolerance of CoO@NS-CSs catalyst are superior to those of commercial Pt/C catalyst. The excellent ORR performance of CoO@NS-CSs catalyst can be attributed to its micro-mesopore structure, high specific surface area (667 m 2 g −1 ), and highly dispersed CoO. This work manifests that the obtained CoO@NS-CSs catalyst is promising to be applied to fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: A thin layer electrochemical cell was successfully developed to study the atmospheric corrosion behavior of copper film in printed circuit board (PCB-Cu) under thin electrolyte layer (TEL) and direct current electric field (DCEF) by electrochemical impedance and electrochemical noise analysis. The electrochemical measurements and SEM morphologies after corrosion test indicate that DCEF decreases the corrosion of PCB-Cu under TEL. The corrosion rate and probability of pitting corrosion of PCB-Cu under DCEF decrease due to the electric migration of aggressive Cl− ion out of working electrode surface. [Copyright &y& Elsevier]

Abstract: The effects of temperature and electric field on atmospheric corrosion behaviour of PCB-Cu under absorbed thin electrolyte layers were investigated by cathodic polarization and electrochemical impedance spectroscopy. Results indicate that the cathodic current density increases with increasing temperature, but decreases with increasing intensity of electric field. Electric field reduces the corrosion rate of PCB-Cu due to the aggressive ions migrating out from PCB-Cu electrode surface under the effect of electric field. When the ions can not freely migrate out from PCB-Cu electrode surface, local enrichment of aggressive ions under the electric field will cause serious localized corrosion of PCB-Cu. [Copyright &y& Elsevier]

Abstract: The adsorption behavior of dodecylamine on a copper–nickel alloy in 0.2M NaCl solutions was studied by electrochemical methods and atomic force microscopy (AFM). The polarization curves showed that dodecylamine had both cathodic and anodic inhibition action, but was mainly a cathodic-type inhibitor. The results of electrochemical impedance spectroscopy (EIS) and in situ AFM phase images indicated that as the inhibitor concentration increased from 0.0005 to 0.005M, the monolayer adsorbed film of inhibitor tended to become more ordered and denser so that corrosion inhibition efficiency tended to increase. Differential capacity curve experiments indicated that the adsorbed dodecylamine film changed the structure of the double-electric layer and made the potential of zero charge (PZC) shift to the positive direction. AFM force curve measurements were also performed and showed that as a result of the adsorption of dodecylamine on copper–nickel alloy surface, adhesive forces between the tip and the sample surface were detected and the long-range electrostatic repulsive forces between the tip and the sample surface were decreased. [Copyright &y& Elsevier]

A single body-centered cubic (BCC)-structured AlCoFeNi medium-entropy alloy (MEA) was prepared by the selective laser melting (SLM) technique. The hardness of the as-built sample was around 32.5 HRC. The ultimate tensile strength (UTS) was around 1211 MPa, the yield strength (YS) was around 1023 MPa, and the elongation (El) was around 10.8%. A novel BCC + B2 + face-centered cubic (FCC) structure was formed after aging. With an increase in aging temperature and duration, the number of fine grains increased, and more precipitates were observed. After aging at 450 °C for 4 h, the formed complex polyphase structure significantly improved the mechanical properties. Its hardness, UTS, YS, and El were around 45.7 HRC, 1535 MPa, 1489 MPa, and 8.5%, respectively. The improvement in mechanical properties was mainly due to Hall–Petch strengthening, which was caused by fine grains, and precipitation strengthening, which was caused by an increase in precipitates after aging. Meanwhile, the FCC precipitates made the alloy have good toughness. The complex interaction of multiple strengthening mechanisms leads to a good combination of strength, hardness, and toughness. [ABSTRACT FROM AUTHOR]

The liquid flow close to the interface has received much attention recently, that is determined by interfacial slip action. In heat exchange tube, the thermal diffusion in the flowing boundary layer is also related to the interfacial flow state. However, the study of convective heat transfer mostly ignores the interfacial slip and medium thermal diffusion. In this study, the variation law of heat transfer efficiency and the actual interfacial concentration under the action of interfacial slip and thermal diffusion in the heat exchange tubes are reported. We find that the heat transfer efficiency of no slip reaches the highest, compared to no slip, that of negative slip significantly reduces (at −0.99 mm, copper: −79.56%; aluminum alloy: −78.60%; carbon steel: −75.85%), and that of positive slip slightly reduces (at 0.58 mm, copper: −16.87%; aluminum alloy: −15.66%; carbon steel: −9.82%). As the slip length increases, the interfacial concentration of positive slip tends to the initial concentration, while the concentration changes rate of negative slip increases (at −0.99 mm, H 2 SO 4 : 110.29%, NaCl: 45.90%, C 2 H 6 O: −28.37%). These results show that the interfacial slip not only affects heat transfer performance but also interfacial concentration, and further affecting the metal corrosion behavior at the heat transfer interface. [Display omitted] • This model can effectively predict the thermal diffusion behavior of solution. • This model can effectively simulate the boundary slip conditions of flow tubes. • The best heat transfer performance occurs under the condition of no slip. • The interfacial concentration change under different slip types can't be ignored. • Provides a new perspective for the design and protection of heat exchange tubes. [ABSTRACT FROM AUTHOR]

• The time-space dependence of thermal diffusion is realized by using COMSOL. • The finite element model can effectively predict the thermal diffusion concentration. • The interface concentration at the heat transfer is not equal to bulk concentration. • Provides a new perspective for the corrosion of metals in heat transfer environments. Heat exchange equipment plays a vital role in the chemical and energy industries; corrosion failure of this equipment causes serious economic losses and potential security threats. Heat transfer affects corrosion behaviour, and promotes the formation of a concentration gradient in a temperature field. However, the concentration changes in corrosive media are often ignored, especially in convective heat transfer environments. In this study, based on thermal diffusion theory, we focus on the concentration distributions of the corrosive media, concentration changes at the solid‒liquid interface and time for the concentration to stabilize under static and laminar heat transfer conditions. The results show that for NaCl and H 2 SO 4 solutions, positive heat transfer decreases, negative heat transfer increases, and corrosive media concentration changes at the interface. The interface concentration changes of H 2 SO 4 reach 26% (considering error: 20% ∼ 31%) and 30% (considering error: 24% ∼ 36%) under static and laminar heat transfer conditions with temperature differences of 50 °C, respectively. In addition, during laminar heat transfer, the concentration distribution undergoing thermal diffusion is jointly determined by the temperature difference and flow rate; the concentration stabilization time is determined by the temperature boundary layer thickness. These results indicate that the actual corrosive media concentrations at the heat transfer interface are not equivalent to the bulk phase concentration in the corrosion solution; the influence of heat transfer on the metal corrosion behaviour cannot be ignored. This study provides a new perspective for metal corrosion and protection in heat transfer environments. [Display omitted] [ABSTRACT FROM AUTHOR]

A new pyrolysis-pickling method was developed to prepare various lead oxide (PbO)/carbon black (CB) composites as the additives in the negative plates of lead-acid batteries to improve their high-rate partial-state-of-charge (HRPSoC) performance. Compared with CB, the PbO/CB composites prepared by the pyrolysis-pickling method have higher content of alkaline surface functional groups ( C alkaline ) and less content of carboxyl surface functional groups ( C COOH ) on CB particles which are still covered with small amount of PbO, meanwhile they have smaller BET surface area, but larger pore volume and average pore width. The hydrogen evolution process in the negative plates containing the PbO/CB composites is inhibited effectively due to the increased C alkaline on CB, while the redox processes (Pb ↔ PbSO 4 ) in these negative plates are accelerated obviously owing to the changes in their microstructure. The PbO/CB composites can impede the growth of PbSO 4 crystals and significantly increase the HRPSoC cycle life of the simulated test cells. In general, the PbO/CB composites with a lower PbO content may be the appropriate additives for the negative plate of lead-acid batteries. [ABSTRACT FROM AUTHOR]

In order to improve the high-rate partial-state-of-charge (HRPSoC) performance of lead-acid batteries for hybrid-electric vehicles, graphene oxide (GO), polypyrrole (PPy) and three PPy/GO composites with different weight ratio of pyrrole to GO ( m py / m GO ) were selected as additives to form negative plates and simulated test cells. The effects of these additives on the electrochemical performance and the microstructure of the negative plate and on the HRPSoC cycle performance of the simulated test cell were investigated. The results indicate that the microstructure of the negative plate is changed with the addition of different additives. GO significantly increases the hydrogen (H 2 ) evolution ability of the negative plate, while PPy has the opposite effect. The incorporation of the proper content of PPy with GO can effectively inhibit the H 2 evolution of the negative plate. Moreover, adding different additives in the negative plate also decreases its total impedance, accelerates the redox processes between Pb and PbSO 4 on it and increases its specific capacitance. GO and the PPy/GO composite with m py / m GO = 1:1 (PG 1 ) can significantly increase the HRPSoC cycle life of the simulated test cell. Considering the H 2 evolution performance and the HRPSoC cycle performance, the PPy/GO composites with a medium m py / m GO ratio, such as PG 1 , may be the appropriate additives for the negative plate of lead-acid batteries. [ABSTRACT FROM AUTHOR]

A dual-circulation testing system was constructed to study the effect of heat flux density (q, −22.28 ∼ +22.54 kW m-2) on the corrosion of an Al–Cu–Mg–Mn alloy in 0.5 M H2SO4 at a constant metal surface temperature (50°C) under different controlling heat transfer states. Their heat transfer parameters were determined quantitatively by COMSOL simulation to keep them except q in constant, highlighting the influence of q on metal corrosion. Compared with the q = 0 condition, the positive heat flux (q > 0) improved the surface layer performance of the Al alloy to inhibit its anodic corrosion process, decreasing its corrosion current density (icorr) by 56% with increasing q to 22.54 kW m-2. While q < 0, the opposite effect occurred, increasing its icorr by 52% at q = −22.28 kW m-2. Heat flux also changed the corrosion reaction's apparent effective activation energy (Ea) and pre-factor, and Ea played a dominating role in changing icorr. [ABSTRACT FROM AUTHOR]

The layer spacing and the expansion of the crystallite volume are unevenly distributed in each layer, which enables the GMC electrode to better adapt to volume change, making for battery property with high capacity and energy density. [Display omitted] Graphite microcrystalline carbon (GMC) is a potential candidate for lithium storage devices because of its high degree of disorder in the crystalline structure. The mechanism that affects the energy-storage ability of GMC in its capacitive coupling state is still unclear. Herein, high-energy GMC is synthesized through a dual-activation approach, and its kinetics and lithium-storage mechanism to boost lithium-ion diffusion are further investigated. The porous graphite microcrystalline provides the structural advantage in raising the Li+ storage capability, promotes the rapid transfer of electrons/ions, and possesses high conductivity. The defective heterostructure stimulates the internal electric field effect, facilitating rapid charge convey and fast diffusion kinetics. The first-principles calculations reveal that the nitrogen vacancies generated in graphite crystallites provide abundant reactive sites and induce excessive electrons around the local nitrogen atoms to form negative charge centers for accelerating the conveyance of Li+. The GMC electrode displays a high capacity of 1195 mAh g−1 at 0.1 A g−1, while the assembled GMC//GMC lithium-ion capacitor device delivers a high energy density of 190.63 Wh kg−1 at 225 W kg−1. This work is expected to offer an in-depth mechanism of electrons/ions diffusion and lithium storage for high-energy carbon electrodes and provide rational ideas for the optimal construction of high-energy carbon-based materials. [ABSTRACT FROM AUTHOR]

Fabricating metal-organic frameworks (MOFs) membranes directly onto metal surfaces as anticorrosive coatings is a feasible approach for the application of MOFs in corrosion protection. The MOFs membranes with specific organic groups can be further customized as versatile platforms for developing various functional coatings. Herein, UiO-66 and UiO-66-NH 2 membranes are synthesized onto aluminum surfaces through a polydopamine-assisted method, which are then grafted with superhydrophobic molecules of perfluorodecyltriethoxysilane (PFDTES). The -COOH groups in UiO-66 and -COOH/-NH 2 groups in UiO-66-NH 2 can serve as firm anchor sites for covalently grafting with PFDTES, enabling robust superhydrophobicity of the as-prepared coatings. The superhydrophobic surfaces exhibit water repellency (water contact angle of ∼165o), chemical (pH and salinity) and wear-resisting robustness, and long-term service durability. They also perform decent anti-fouling, self-cleaning, and anti-icing properties. Notably, sustainable corrosion protection can be provided by both coatings during immersion in saline solution (3.5 wt% NaCl) for one month and during a two-week salt spray test. Compared with UiO-66, the -NH 2 groups on UiO-66-NH 2 as extra grafting sites for firmer immobilization of more PFDTES molecules facilitate more durable superhydrophobicity and corrosion protection. We believe that this work could offer valuable insights into the multi-functional development of MOFs membranes-based coatings. UiO-66 and UiO-66-NH 2 membranes covalently grafted with PFDTES molecules serve as effective superhydrophobic and anti-corrosive coatings. [Display omitted] • UiO-66 and UiO-66-NH 2 MOFs membranes are grafted with perfluorodecyltriethoxysilane. • The covalently grafting enables robust superhydrophobicity of the MOFs membranes. • The coatings perform decent anti-fouling, self-cleaning, and anti-icing properties. • Durable corrosion protection can be provided by the coatings. [ABSTRACT FROM AUTHOR]

An excellent anti-corrosion and initial corrosion-warning composite coating (MAO/Na 2 MoO 4 /8-HQ/PP/WPU) was constructed on AZ31B magnesium alloy using micro-arc oxidation (MAO) technology, vacuum adsorption and spin-coating methods. The microstructure and chemical composition of the coating samples were characterized using XRD, FTIR, SEM, XPS, and Raman technologies. Scratches experiment confirms that MAO/Na 2 MoO 4 /8-HQ/PP/WPU coating could detect early corrosion at a damaged coating area. Electrochemical and optical morphology results show that it still maintains an unexceptionable corrosion protection performance with a high |Z| 0.01Hz value (1.017 × 107 Ω·cm2) after immersion in a 3.5 wt% NaCl solution for 60 days, one order of magnitude larger than that of blank WPU coating. Combined with ion selective test and XPS depth analysis, its corrosion protection mechanism of the coating is clearly explained. This study can provide new insights for the design and protective mechanisms of functional coatings. [Display omitted] • The MAO/Na 2 MoO 4 /8-HQ/PP/WPU composite coating exhibits excellent long-term corrosion resistance. • The color change of PP indicator loaded in the composite coating serves as an initial warning for localized corrosion. • Corrosion protection mechanism is firstly elucidated from the perspective of ion selectivity, corrosion inhibitor and physical isolation behaviors of the composite coating. [ABSTRACT FROM AUTHOR]

In this work, the influence of temperature on the corrosion behavior of AlCoCrFeNi2.1 eutectic high-entropy alloy in a chloride-containing sulfuric acid solution was investigated using electrochemical measurement, X-ray photoelectron spectroscopy, and scanning electron microscopy. Results show that the passive film of AlCoCrFeNi2.1 is stable in chloride-containing sulfuric acid solutions at low temperatures, while an unstable film forms on the alloy at high temperatures. Furthermore, temperature changes the proportion of hydroxide and oxide in Fe and Cr, but it has no noticeable effect on Al and Ni, which is a significant factor on the passive behavior. L12 phase exhibits good corrosion resistance at different temperatures. Pitting occurred on B2 phase in the chloride-containing sulfuric acid solution at a low temperature of 5 °C, while pitting and dissolution take place on AlCoCrFeNi2.1 in the acid solution at room temperature and above. [ABSTRACT FROM AUTHOR]

The electrochemical migration (ECM) time to failure (TTF) tests for pure tin in the bromide-containing environment were carried out using the thin electrolyte layer (TEL) method. In-situ electrochemical measurement was made to monitor the ECM behavior while the changes of surface morphology and localized pH during the ECM process were real-time observed using the 3D optical digital microscope. Microstructure and composition of products obtained after the ECM tests were characterized using the scanning electron microscope, energy-dispersive spectrometer and X-ray diffractometer. Results indicated that the growth rate of dendrite increased with bromide ion concentration at low bromide concentration levels, and it decreased at medium concentration levels. Tree-like tin dendrites covered with white precipitates are formed after the ECM tests. As for the high bromide ion concentration condition, no dendrite can be found and a thick layer of precipitate is formed between the twin electrodes. This precipitate layer has a higher thickness than the electrolyte layer, which can act as a barrier layer retarding ionic migration and thus inhibiting the ECM failure. Relevant mechanism has been proposed to clarify the effect of bromide ions on the ECM of pure tin under the thin electrolyte layer. [ABSTRACT FROM AUTHOR]

In this work, electrochemical migration behaviour of tin under electrolyte layers with different thicknesses was investigated using thin electrolyte layer method. The results show that the time to short circuit first increases and then decreases with increasing thickness of the electrolyte layer, the maximum value is present at 100 μm. Inductively Coupled Plasma Source Mass Spectrometer was employed to measure the local concentration of tin ions. The result shows that the lowest local concentration of tin ions is present at the 100-μm-thick electrolyte layer, resulting in a maximum value in the time to short circuit. [ABSTRACT FROM AUTHOR]

• Incremental learning predict corrosion fatigue crack growth rate with accuracy > 0.95. • Incremental learning balances new tasks and old knowledge with forgetting rate < 0.05. • Replay mechanism overcomes catastrophic forgetting and preserves previous experience. • Structural optimization and regularization adapt to new data and prevent overfitting. The 2xxx series aerospace aluminum alloys, vital for aircraft structures due to their excellent mechanical strength and corrosion resistance, face challenges with corrosion fatigue failure, impacting material integrity and aircraft safety. Accurately predicting the corrosion fatigue crack growth rate is crucial for these materials' reliability in aerospace applications, ensuring safety and operational efficiency. Various unique incremental learning strategies like structural optimization, regularization, and replay were used to enhance the predictive model's adaptability to continually updated data without the need to retrain the entire model, thus overcoming "catastrophic forgetting." Based on these strategies, a series of XGBoost models for the prediction of corrosion fatigue crack growth rate in aerospace aluminum alloys have been developed. The results demonstrate that the replay strategy excels in maintaining the accuracy of historical data, while structural optimization and regularization strategies stand out in adapting to new data and effectively preventing overfitting. Combining these three strategies, the models maintain good accuracy and a low forgetting rate across all steps, with an accuracy rate exceeding 0.95 and a forgetting rate below 0.05 in all incremental steps, showcasing excellent knowledge retention capabilities. The models achieve a balanced performance in learning new tasks and retaining old knowledge. [ABSTRACT FROM AUTHOR]

Ag NPs are incorporated in the surface layer of salicylic (SA) and tartaric (TA) ions co-doped PPy to form compact and stable Ag NPs-PPy(TA+SA)/Zn bilayer coating on ZK60 magnesium alloy, which completely isolates corrosive media before its breakage. Ag NPs form micro-galvanic cells with polarons PPyn+ and block PPy ion channels to inhibit PPy degradation rate, significantly enhancing the coating's protection time in Hank's solution. [Display omitted] • Ag NPs-(salicylic + tartaric) co-doped PPy/Zn bilayer coating is prepared on ZK60. • Ag species (Ag+/Ag0≈0.1) are distributed in PPy's surface layer (hundreds of nm). • Ag species are crucial in prolonging the coating's protection time to 113 ± 2.6 days. • Ag NPs-PPy(TA + SA) shows good cytocompatibility and antibacterial properties. For the biodegradable implant applications, silver nanoparticles (Ag NPs) are incorporated in polypyrrole (PPy) co-dopped with tartrate (TA) and salicylate (SA) anions to obtain multi-functional Ag NPs-PPy(TA + SA)/Zn bilayer coating on ZK60 magnesium alloy with high protective and antibacterial properties. The effects of Ag NPs on the composition, structure, and antibacterial and protective properties of Ag NPs-PPy(TA + SA)/Zn bilayer coating are studied. Incorporating Ag NPs influences the electrochemical growth conditions of PPy(TA + SA), possibly increasing the defects in PPy chains. Its surface morphology and film thickness are similar to PPy(TA + SA). However, Ag species (Ag+/Ag0 ≈ 0.1) are only distributed in the PPy surface layer (hundreds of nm), containing some adsorbed and agglomerated Ag NPs on its surface. In Hank's solution at 37 °C, Ag NPs-PPy(TA + SA) experiences slow degradation, and the Ag content loses slowly to zero. Its protection time is significantly improved to 113 ± 2.6 days, much more prolonged than PPy(TA + SA) (54 ± 1.5 d), suggesting the crucial role of Ag NPs. After Ag NPs-PPy(TA + SA) is broken due to its local destruction, ZK60 displays typical local corrosion. Ag NPs-PPy(TA + SA) exhibited excellent cytocompatibility and antibacterial properties. The corresponding mechanism involved is thoroughly discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Atmospheric corrosion of copper is studied under an alternating electric field. [•] The effects of the amplitude, frequency, and waveform are determined. [•] Corrosion mechanism of copper with different conditions is discussed. [ABSTRACT FROM AUTHOR]

To enhance the corrosion protection of the polypyrrole/zinc (PPy/Zn) bilayer coating on biodegradable ZK60 magnesium alloy in Hank's solution at 37 °C, sodium salicylate (NaSA) in different concentrations (C NaSA , 0.5–4.0 mM) is selected as a co-doping reagent of tartrate anions (TA−), and an electropolymerization method that combines potentiostatic and galvanostatic synthesis is developed to prepare PPy(TA + SA)/Zn bilayer coatings. The co-doping of SA− suppresses the growth of PPy and notably increases its synthesis potential (E poly) with increasing C NaSA. The co-doped PPy(TA + SA) films have a surface morphology and thickness similar to the PPy(TA) film. However, their chemical composition, structure, and adhesion strength change notably due to their varying growth conditions. In the long-term immersion test of PPy(TA + SA)/Zn/ZK60 samples, the PPy(TA + SA)/Zn coatings exhibit high stability, and the coating prepared with C NaSA = 1.0 mM has the most prolonged protection time (54 ± 1.5 d). As C NaSA increases, the co-doped PPy(TA + SA) film becomes heavily over-oxidized to produce more defects on PPy chains due to the high E poly , ultimately decreasing the protection time to 40 ± 1.0 d. The corresponding mechanism involved is thoroughly discussed. Salicylic (SA) and tartaric (TA) ions co-doped PPy films are electropolymerized, undergoing potentiostatic and galvanostatic synthesis, to prepare compact and stable PPy(TA + SA)/Zn bilayer coating on ZK60 magnesium alloy. The PPy(TA + SA) film completely isolates the corrosion media from the Zn/ZK60 substrate and degrades very slowly, notably enhancing its protection time in Hank's solution. [Display omitted] • Co-doping salicylic (SA) with tartaric (TA) ions notably increases PPy's stability. • Combine potentio- and galvanostatic synthesis to grow co-doped PPy(TA + SA) • The PPy(TA + SA)/Zn bilayer coating on ZK60 notably enhances corrosion resistance. • The PPy(TA + SA) film prolongs its protection time to 54 ± 1.5 days in Hank's solution. • PPy(TA + SA) shows low antibacterial properties for doping minimal SA ions. [ABSTRACT FROM AUTHOR]

Magnesium and its alloys possess elastic modulus close to natural bone and degradable effects, making them widely applied in bone implantation. However, their rapid corrosion in a simulated body fluid restricts further application. This work firstly employs micro arc oxidation (MAO) technique to in situ grow a corrosion-resistant ceramic layer on the surface of AZ31B Mg alloy. Subsequently, nano ZnO particles are modified using a silane coupling agent and then incorporated into a poly(ε-caprolactone) coating with chitosan through a simple blending and micellar method to obtain the PCNZ composite coating. The chemical composition and micro structure are characterized by FTIR, XRD, SEM and AFM. Electrochemical tests and antibacterial experiments indicate that PCNZ composite coating exhibits excellent long-term corrosion resistance and certain antibacterial ability, demonstrating potential application in the field of bone implantation. • The MAO/PCNZ composite coating on AZ31B Mg alloy surface was constructed through a simple blending and micellar method. • The linear PCL coating was cured into cross-linked PCNZ composite coating by introduction of CS and amino-modified ZnO nanoparticles. • The incorporation of CS and amino-modified ZnO nanoparticles endows MAO/PCNZ composite coating with excellent corrosion resistance and antibacterial properties. [ABSTRACT FROM AUTHOR]

As a key component in flexible optoelectronic devices, flexible transparent conductive films will become a strategic material in optoelectronic products. Among them, silver nanowire (AgNW) transparent conductive film (TCF) is the most marketable and promising optoelectronic material. However, the nano-size effect makes AgNW TCF less weather-resistant and prone to corrosion in the service occasions, leading to degradation or even failure of the conductivity of optoelectronic devices. Therefore, poor stability is one of the key issues hindering the large-scale industrialization of AgNW TCF. This article focuses on the application scenarios and stability of AgNW TCF: firstly, its related application scenarios in flexible displays, thin-film solar cells, and electromagnetic shielding glass are summarized; then the impact of service environment (environmental pollutants, temperature, humidity, lighting, etc.), mechanical effects, thermoelectric coupling effects on the stability of AgNW TCF are discussed; finally, the optimizing strategies are put forward about how to improve the stability of AgNW TCF. It provides a reference for researchers to improve the stability of AgNW TCF. • It analyzes advantages and limitations of AgNW TCF as a flexible transparent conductive film. • Impact of environmental factors, mechanical action, and thermo-electric coupling effects on stability of AgNW TCF have been discussed. • It looks forward to future research directions of AgNW TCF. [ABSTRACT FROM AUTHOR]

• The morphologies of track and melt pool were closely related to laser energy. • The size of melt pool showed diverse variation with increasing layer thickness. • The severe balling, spatters and unstable melt pool at large layer thickness. • The highest relative density could reach to 99.9 % at 90 μm layer thickness. Large layer thickness is essential to increase building rate, but excessive layer thickness easily lead to defects which negatively affect component quality. The evolution of track morphology, melt pool characteristics and defects of additively manufactured mold steel by using various larger layer thickness (60 and 90 μm) while also varying the laser energy density was investigated systematically. Results indicated that the morphologies of single tracks shifted sequentially from discontinuousness to continuous irregularity and continuous regularity with the increasing line energy density at 60 μm layer thickness. The width and depth of melt pool increased substantially with the line energy density increased from 0.4 to 1.3 J/mm, while the height of melt pool was nearly constant. Correspondently, transition of the melt pool based on the depth-to-width ratio from balling to conduction and keyhole modes was observed. When the layer thickness increased from 60 to 90 μm, the average build percentage of the single tracks decreased by 43 % with increasing line energy density from 0.26 to 0.51 J/mm, and more spatters around the surface of tracks were found at 0.8 J/mm. Interestingly, the average width of the melt pool decreased by 37 μm, while the height of melt pool increased by 45 μm. More small spherical gas pores (5–15 μm) occurred in bottom of keyhole due to trapped vapor at high energy density. The decrease in melt width with increased layer thickness is most likely due to the weakened Marangoni convection. Finally, formation mechanism of lack-of-fusion defects and gas pores with larger layer thickness processing were analyzed based on melt pool characteristics, such as spheroidization, keyhole and spatters. [ABSTRACT FROM AUTHOR]

A novel strategy of dual system activation is developed to synthesize the nitrogen-doped biomass-derived carbon with hierarchically porous structure for high-performance lithium-ion storage properties. [Display omitted] Active biomass-derived carbons are brought into focus on boosting high-performance lithium storage. However, their low electric conductivity and poor ion diffusion kinetics during the lithium storage reactions remain confusing topics. This study demonstrates a novel and effective strategy of dual system activation process to construct the nitrogen-doped biomass-derived carbon with hierarchically porous architecture (HNBC), which is composed of the three-dimensional porous networks connected by carbon nanorods and the flake-like edges constructed by carbon nanosheets. A large amount of nitrogen doping can improve the conductivity and facilitate the charge transfer during charging/discharging, while the hierarchically porous structure can decrease the diffusion path for lithium-ion transport, enabling fast diffusion and charge-transfer dynamics. The HNBC electrode displays a high lithium-ion storage capacity of above 1392 mAh g−1 at 0.1 A g−1 and superior stability. Moreover, the assembled asymmetric lithium-ion capacitor exhibits excellent cycling stability and delivers a high power density of 225 W kg−1 with an energy density of 186.31 W h kg−1. This dual system activation strategy may inspire the reasonable design of new-generation progressive carbon-based electrodes for high-performance lithium storage devices. [ABSTRACT FROM AUTHOR]

Abstract: Polypyrrole/sulfate–copper (PPy/SO4–Cu) complexes were synthesized by different methods, including the one-step potential pulse method and the traditional direct current (DC) two-step method. The two methods were analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) to find out the influence of the different synthesis methods on the film composition and structure. Finally, the alkalescence stability of these films was studied by comparing the electroredox activity through cyclic voltammetry (CV) and electrochemical impedance (EIS) measurements. The results demonstrate that the PPy/SO4–Cu films synthesized by different methods show the same Cu combination model (i.e., Cu+ was combined with N on the PPy chains to form the PPy/SO4–Cu films). However, the film made by the one-step pulse method had smaller PPy particles and much higher Cu content. In addition, the PPy–Cu film synthesized by the one-step pulse method showed improved alkalescence stability, which can be attributed to the higher Cu content present uniformly in the film. [Copyright &y& Elsevier]

Purpose - This paper seeks to investigate the different inhibition performance and adsorption behaviour of dodecylamine in acidic and neutral environments and to understand further the inhibition mechanism of dodecylamine in CO2-saturated brine solution. Design/methodology/approach - The inhibition performance and adsorption behaviour of dodecylamine on N80 steel in CO2-saturated brine solution in acidic and neutral environments were investigated by potentiodynamic polarization, electrochemical impedance spectroscopy and the attenuated total reflection-Fourier transform infrared spectroscopy. Findings - Corrosion potentials exhibited a pronounced shift in the positive direction at higher concentrations of dodecylamine. The inhibition efficiency of dodecylamine was shown to be pH-dependent. The effective inhibition concentration of dodecylamine decreased from pH 4.9 to 7.4. In a neutral environment, the inhibitor was shown to affect the deposition of the corrosion products and provide more active sites to bond with the inhibitor. More alkaline environments made the electron cloud density of dodecylamine much higher, which was more favourable to the interaction of dodecylamine and the naked metal base, and hence dodecylamine had a much better inhibition performance in a neutral environment than in acidic environments. Originality/value - This paper provides information regarding the inhibition performance and adsorption behaviour of dodecylamine on N80 steel and probes the inhibition mechanism of dodecylamine in acidic and neutral environments. The results of the work contribute to an understanding of the inhibition mechanism of the inhibitor in different environments, which will be useful for effective design and choice of inhibitors in CO2 corrosion. [ABSTRACT FROM AUTHOR]

Integrating ultralow-Pt alloy into nanocarbons: Ternary PtCoNi alloy with ultralow Pt loading integrated in nitrogen-doped nanocarbon architecture endows an excellent half-cell activity and single-cell performance. [Display omitted] Developing efficient platinum (Pt)-based electrocatalysts is enormously significant for fuel cells. Herein, we report an integrated electrocatalyst of ultralow-Pt alloy encapsulated into nitrogen-doped nanocarbon architecture for efficient oxygen reduction reaction. This hybrid Pt-based catalyst achieves a mass activity of 3.46 A mg pt −1 at the potential of 0.9 V vs. RHE with a negligible stability decay after 10,000 cycles. More importantly, this half-cell activity can be expressed at full cell level with a high Pt utilization of 10.22 W mg Pt −1 cathode and remarkable durability after 30,000 cycles in single-cell. Experimental and theoretical investigations reveal that a highly strained Pt structure with an optimal Pt-O binding energy is induced by the incorporation of Co/Ni into Pt lattice, which would account for the improved reaction kinetics. The synergistic catalysis due to nitrogen-doped nanocarbon architecture and active Pt component is responsible for the enhanced catalytic activity. Meanwhile, the strong metal-support interaction and optimized hydrophilic properties of nanocarbon matrix facilitate efficient mass transport and water management. This work may provide significant insights in designing the low-Pt integrated electrocatalysts for fuel cells and beyond. [ABSTRACT FROM AUTHOR]

Magnesium alloy has a wide application prospect in the carrier aircraft due to its high strength to weight ratio, high specific strength and stiffness. However, the weak corrosion resistance and radar stealth performance limits its further development. In this work, micro-arc oxidation (MAO) technology was used to improve the corrosion resistance of AZ91D magnesium alloy through the generation of ceramic oxide film; then the porous MAO layer as a bond layer was anchored with silicone resin (SI) coating doped with nano cobalt ferrite (CFO) for further improvement of anti-corrosion performance and radar absorption performance. The composite coatings (MAO, SI, MAO + SI, SI + CFO, MAO + SI + CFO) on AZ91D magnesium alloy were prepared, and their long-term corrosion protection performance and wave-assimilation performance were evaluated by electrochemical impedance spectroscopy (EIS) and microwave vector network analyzer (VNA). The EIS results show that after 63 days immersion in 3.5 % NaCl solution, impedance module value of the MAO + SI + CFO coating at 0.01 Hz still keeps 108 Ω cm2, suggesting its excellent anti-corrosion performance. From the VNA consequences, the minimum reflection loss of MAO + SI + CFO coating is −23.10 dB, and the effective absorption bandwidth is 4.07 GHz, illustrating its good electromagnetic absorption performance. This work provides a new idea for the multi-functionalization of aviation lightweight magnesium alloys. • Advanced Bonding Layer: Combine porous MAO, SI, and nano cobalt ferrite for enhanced durability. • Synergistic Anti-Corrosion: MAO + SI + CFO coating excels after 63 days in 3.5 wt% NaCl solution, showcasing lasting performance. • Dual Defense Capability: Impressive 109 Ω cm2 impedance and −23.10 dB reflection loss demonstrate excellent protection. [ABSTRACT FROM AUTHOR]

• PPy NWs' entire surfaces suffer attacks easily in NaOH to lose most doing anions. • PPy NWs degrade uniformly, decreasing NWs diameter and expanding thickness. • Electroactivity degradation of PPy NWs in NaOH follows the first-order kinetics. • PPy film's natural degradation kinetics model is validated to apply to PPy NWs. • PPy NWs' unique structure greatly accelerates its degradation rates. The polypyrrole (PPy) nanowires doped with p -toluenesulfonate ions (PPy/pTS NWs) are prepared and degraded in aerated and deaerated NaOH solutions (C NaOH =0.02 - 0.5 M) for different times to examine their natural degradation behavior and kinetics. After degradation, the fluffy PPy/pTS NWs network film generally exhibits a uniform natural degradation state with apparent damaged areas on the nanowires' surface, decreased nanowire diameter, and increased film thickness. The electroactivity degradation of PPy/pTS NWs still follows the first-order degradation kinetics, like the bulk-structured PPy/pTS films. The natural degradation kinetics model established from the bulk-structured PPy films is proven to apply to PPy/pTS NWs. The rate equations for the chemical and electrochemical degradation of PPy/pTS NWs in NaOH solutions are determined. Additionally, it is confirmed that the electrochemical degradation process is the dominant factor, while C NaOH significantly impacts the chemical degradation process. The structural features of PPy/pTS NWs do not alter the chemical and electrochemical degradation processes but significantly accelerate the degradation rates. This research will contribute to our understanding of the degradation kinetics of PPy nanomaterials and support their practical applications. [ABSTRACT FROM AUTHOR]

In this work, 2-amino-5 mercapto-1, 3, 4-thiadiazole/boron nitride nanosheets (ATT/BNNS) nanofillers were prepared via using ATT as intercalating agent to exfoliate BNNS by a liquid-phase assisted ultrasound method. The FTIR and the XPS consequences testify that the corrosion inhibitor ATT is successfully grafted onto BNNS. TEM results indicate that BNNS is adequately exfoliated by ATT and the agglomeration phenomenon is alleviated. BNNS, ATT and ATT/BNNS nanofillers were processed into the waterborne epoxy (WEP) respectively, and WEP composite coatings were then fabricated by a spraying method on the copper electrode. The EIS measurements demonstrate that WEP ATT/BNNS coating displays the best protective performance in combination with optical morphology observation under saline immersion, compared with other three coatings. It is mainly attributed to the combined action of active protection from ATT inhibitor and physical barrier from BNNS. The two-dimensional BNNS nanofiller dispersed in the WEP coating plays the role of physical barrier, forms a "labyrinth effect", extends the invasion way of corrosive media, thus enhancing the physical barrier effect in the composite coating. Furthermore, ATT inhibitor can also diffuse through the coating to the copper substrate and build a safety shield to hold back further corrosion. Importantly, after 40 days immersion in 3.5 wt% NaCl solution, the value of impedance module at 0.01 Hz of WEP ATT/BNNS coating is about 2 orders of magnitude larger than that of pure WEP coating, revealing superior long-term anticorrosion performance. • The 2-amino-5 mercapto-1, 3, 4-thiadiazole (ATT) is selected as intercalating agent to exfoliate boron nitride nanosheets (BNNS) through a liquid-phase assisted ultrasound method. • The synergistic effect of physical barrier from BNNS and active protection from ATT inhibitor endow WEP ATT/BNNS coating excellent the long-term protective performance. • The impedance module value for WEP ATT/BNNS coating at 0.01 Hz is about 2 orders of magnitude higher than that of pure WEP coating after 40 days immersion in 3.5 wt% NaCl solution. [ABSTRACT FROM AUTHOR]

A zeolitic imidazole framework-8 (ZIF-8) derivative was synthesized and developed as the corrosion inhibitor of copper in 0.5 mol/L NaCl solution, and its inhibition performance was investigated by electrochemical measurement and surface analysis. Results show that the ZIF-8 derivative could effectively inhibit copper from corrosion, and the inhibition efficiency was 87.2% at an optimal ZIF-8 derivative concentration of 45 mg/L. The corrosion inhibition mechanism of the ZIF-8 derivative could be explained as follows: the amino functional groups and the π-system formed by aromatic rings of the ZIF-8 derivative were tightly adsorbed on the copper substrates, which systematically formed a hydrophobic film, thereby effectively inhibiting the corrosion caused by aggressive ions. Unlabelled Image • A new zeolitic imidazole framework-8 (ZIF-8) derivative was synthesized. • ZIF-8 derivative could form hydrophobic adsorbed films on copper surface. • ZIF-8 derivative could effectively inhibit copper from corrosion. [ABSTRACT FROM AUTHOR]

Inhibition effect of sodium N -lauroyl sarcosinate and zinc sulfate on the galvanic corrosion between carbon steel and stainless steel in 1% NaCl solution was investigated. The results of electrochemical measurements revealed that anodic and cathodic inhibitors inhibited galvanic corrosion by reducing the potential difference between the electrodes in two different ways. The values of corrosion potential and corrosion resistance of carbon steel increased after adding sodium N-lauroyl sarcosinate. In contrast, corrosion potential of stainless steel was shifted to the more negative region after adding zinc sulfate. X-ray photoelectron spectroscopy and scanning electron microscopy were applied to investigate the chemical compositions and morphologies of the films. [ABSTRACT FROM AUTHOR]

• The passive film properties of Ce-added AlCoCrFeNi 2.1 alloys are studied for the first time. • Ce addition is not conducive to corrosion resistance of the AlCoCrFeNi 2.1 alloy in H 2 SO 4 solution. • Ce increases the doping density and reduces the proportion of Cr oxides in the passive film. Eutectic high-entropy alloys (EHEAs), represented by AlCoCrFeNi2.1, are considered to be promising materials. However, the study of the corrosion behavior of EHEAs remains limited, which hinders further development. This study investigated the effect of Ce addition on the electrochemical behavior and passive film properties of AlCoCrFeNi 2.1 EHEAs in H 2 SO 4 solutions. The results show that the addition of Ce changed the properties of the passive film formed on the alloys, resulting in reduction in the proportion of Cr 2 O 3 , and thereby reduced the corrosion resistance. Moreover, a higher Ce content in the EHEAs was found to correspond to a more pronounced deterioration in corrosion resistance. Compared with the film formed at 0.2 V vs SCE , the film formed at 0.5 V vs SCE exhibited more optimal physicochemical properties, leading to a decrease in the passive current density. Notably, Ce was absent in the film formed at 0.2 V vs SCE , but present at 0.5 V vs SCE. [ABSTRACT FROM AUTHOR]

The electrochemical migration (ECM) behavior of Sn-3.0Ag-0.5Cu solder alloy under thin electrolyte layers was investigated using a technique based on the coupling of in situ electrochemical measurements and optical observation. Results showed that the mean time to failure first increased and then decreased as thickness of the electrolyte layer increased, the maximum value was present at 200 μ m. The higher the bias voltage applied, the faster was the rate of dendrite growth. And, Sn leaded the ECM of SAC305 solder alloy. Mechanisms relevant have been proposed to explain the ECM behavior of Sn-3.0Ag-0.5Cu solder alloy. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Inhibition effect of 2-mercaptobenzothiazole (MBTH) in CO 2 -H 2 O condition is studied. • Excess positive charges accumulated on steel surface in supercritical CO 2 system. • Excess negative charges are on steel surface in non-supercritical CO 2 system. • MBTH shows excellent inhibition performance in supercritical CO 2 -H 2 O condition. Abstract The corrosion inhibition performance of 2-mercaptobenzothiazole (MBTH) for carbon steel in a CO 2 -H 2 O system was investigated by weight loss, surface analysis, electrochemical measurements, and quantum chemical calculations. Results showed that MBTH could effectively protect carbon steel from CO 2 corrosion and inhibition efficiency of MBTH in supercritical CO 2 was higher than that in non-supercritical CO 2 situation. The differential capacitance curves revealed that excess positive charges would be on the surface of carbon steel in the supercritical-CO 2 system while negative charges accumulated on carbon steel surface in non-supercritical CO 2 condition. The adsorption model was proposed to explain the inhibition mechanism of MBTH. [ABSTRACT FROM AUTHOR]

Abstract Free-standing polypyrrole (PPy) films hold promising potential in flexible energy storage devices, actuators, and artificial muscles, but they are limited by service failure. In this work, free-standing PPy/p-toluenesulfonate (PPy/pTS) films with different thickness (1.8 and 4.2 μm) were prepared, and their degradation behavior in aerated and de-aerated 0.5 M NaOH was investigated to make clear the changes of chemical and electrochemical degradation processes on free-standing PPy films. The degradation of electrochemical activity of the free-standing PPy film leads to an obvious increase in its internal resistance and shows similar kinetics as the PPy film with a Pt substrate, i.e. one degradation stage and its rate follows first-order kinetics. The degradation rate constant (k) in aerated NaOH increases largely owing to the existence of the dominant electrochemical degradation process. The k value of the thick film (4.2 μm) decreases obviously resulting from a more ordered and compact structure, which limits ion diffusion in the polymer matrix so as to greatly inhibit the chemical degradation process. The free-standing PPy film shows lower electrochemical activity and much larger k values compared with the PPy film with a Pt substrate under the same condition. The mechanisms involved were discussed. Highlights •. Degradation of free-standing PPy/pTS films (1.8 and 4.2 μm) is studied. •. Degradation of free-standing PPy films increases its internal resistance obviously. •. One degradation stage is shown and its rate follows first-order kinetics. •. Thick free-standing PPy films show much smaller degradation rate constants. [ABSTRACT FROM AUTHOR]

The inhibition effects of garlic extract on copper corrosion under a thin electrolyte layer (TEL) were investigated using weight-loss measurements, electrochemical methods and surface analysis. Results showed that the volatile organosulfur compounds of garlic extract, such as diallyl trisulfide and di-2-propenyl disulfide, among others, could adsorb on the surface of copper and have a significant inhibitory effect on copper corrosion. Garlic extract acted as a mixed-type inhibitor for copper under TEL. Surface analyses, such as scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), were conducted to illustrate the inhibitive mechanisms of this plant extract under a TEL. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Sn-3.0Ag-0.5Cu alloy mainly showed local corrosion under thin electrolyte layers. • Intermetallic compounds and β-Sn crystal boundary boosted Cl− infiltration. • Adsorption of Cl− and OH− on surface oxides made local passivating film thin. • Corrosion products at pitting corrosion boundary region boosted pitting corrosion. Abstract Corrosion behavior of Sn-3.0Ag-0.5Cu lead-free solder alloy under chlorine-containing thin electrolyte layers is studied. The emphasis is laid on discussion about influences of addition of alloying elements, concentration of chloride ion and thickness of electrolyte layer on its corrosion behavior. Results indicate that: mainly local corrosion occurs to the alloy; Existence of intermetallic compounds and β-Sn crystal boundary facilitates the process of Cl− infiltration into the base and galvanic corrosion. Metal ions are accumulated in pitting corrosion region, and hydrolysis of metallic ions promotes the solution acidification and transverse development of pitting corrosion. [ABSTRACT FROM AUTHOR]

A novel and simple method to improve the corrosion resistance of copper by constructing a three-dimensional (3D) 1-dodecanethiol self-assembled monolayer (SAM) in 3.5% NaCl solution is reported in this study. Several drops of 1% H3PO4 solution are thinly and uniformly distributed on copper surface to form a 3D nanostructure constituted by Cu3(PO4)2 nanoflowers. The anticorrosion properties of 1-dodecanethiol SAM on copper surface and on copper surface that is treated with H3PO4 solution were evaluated. Results demonstrated that 1-dodecanethiol SAM on bare copper surface exhibits good protection capacity, whereas a copper surface that is pretreated with H3PO4 solution can substantially enhance the corrosion resistance of 1-dodecanethiol SAM. [ABSTRACT FROM AUTHOR]

The effect of doping anions on the degradation of electrochemical activity of polypyrrole (PPy)/A (A: SO 4 2− , pTS − , PSS − , and GO) films in NaOH is investigated by various electrochemical methods and microscopic analyses. The degradation rates of PPy/A films follow first-order k inetics. The PPy/SO 4 and PPy/GO films have two degradation stages with higher rate constants ( k ), while the PPy/pTS and PPy/PSS films just show one degradation stage with much lower k values. The exchange ability of doping anions with OH − and the penetration of OH − into the inner film are two crucial factors for the degradation of PPy in NaOH. [ABSTRACT FROM AUTHOR]

The Fructus cannabis protein extract powder (FP), was firstly used as a green and high effective corrosion inhibitor through a simple water-extraction method. The composition and surface property of FP were characterized by FTIR, LC/MS, UV, XPS, water contact angle and AFM force-curve measurements. Results indicate that FP contains multiply functional groups, such as N H, C O, C N, C O, etc. The adsorption of FP on the carbon steel surface makes it higher hydrophobicity and adhesion force. The corrosion inhibition performance of FP was researched by electrochemical impedance, polarization curve and differential capacitance curve. Moreover, the inhibitive stability of FP, and the effects of temperature and chloride ion on its inhibition property were also investigated. The above results indicate that the FP exhibits excellent corrosion inhibition efficiency (~98 %), and possesses certain long-term inhibitive stability with inhibition efficiency higher than 90 % after 240 h immersion in 1 M HCl solution. The high temperature brings about the FP desorption on the carbon steel surface, while high concentration of chloride ion facilitates the FP adsorption. The adsorption mechanism of FP follows the Langmuir isotherm adsorption. This work will provide an insight for protein as a green corrosion inhibitor. [ABSTRACT FROM AUTHOR]

A polypyrrole/zinc (PPy/Zn) bilayer coating is prepared to significantly improve the corrosion resistance of ZK60 magnesium alloy in 37 °C Hank's solution to meet the requirements for biodegradable metals. The zinc coating composed of dense and uniform flake-like zinc crystals displays good abrasion resistance and adhesion strength, acting as a vital intermediate layer for growing the PPy film doping with tartrate anions (TA−). The prepared PPy/TA films (10, 20 and 28 μm) on the Zn coating are compact and have high stability in Hank's solution. The electrochemical and hydrogen evolution tests for PPy/Zn/ZK60 specimens show that the PPy/TA film's stability determines the protective performance of PPy/Zn coating in a long immersion period. The PPy(20 μm)/Zn coating has the longest protection time (40 ± 4 days), and too thick PPy film (28 μm) damages its structure to accelerate breakage, developing local corrosion quickly on ZK60. The corrosion mechanism involved is discussed. PPy/Zn bi-layered coating prepared on ZK60 magnesium alloy significantly improves its corrosion resistance in Hank's solution. The compact PPy film on the Zn coating is stable under chemical and electrochemical attacks, preventing the entrance of corrosion media to prolong its protection time. After PPy is broken, a local corrosion area develops quickly on ZK60. [Display omitted] • PPy/Zn bi-layered coating is prepared on ZK60 for biodegradable applications. • Zn coating acts as a vital intermediate layer for growing high-stability PPy. • PPy doping with tartrate anions (PPy/TA) has high stability in Hank's solution. • PPy/TA film's stability determines the protective performance of PPy/Zn coating. • Too thick PPy/TA film may damage its structure to accelerate its breakage. [ABSTRACT FROM AUTHOR]

The corrosion kinetics of PPy/SO 4 in aerated and de-aerated NaOH solutions (0.02–0.5 M) were investigated and the interaction between chemical and electrochemical corrosion processes was verified. The corrosion of PPy is mainly caused by the chemical attack of OH − in de-aerated NaOH, but is accelerated largely in aerated NaOH for the occurrence of the electrochemical processes. These two processes are mutually promoted in aerated NaOH. At a constant NaOH concentration ( C NaOH ), two corrosion stages are proved to follow first-order kinetics. In each corrosion stage, the chemical and electrochemical processes have different kinetic behavior and C NaOH has important influence on them. [ABSTRACT FROM AUTHOR]

This paper presents a new strategy involving the introduction of the common cationic surfactant cetyltrimethylammonium bromide (cetrimonium bromide, CTAB) to inhibit the electrochemical migration (ECM) of tin in thin electrolyte layers containing chloride ions. The inhibitory effect of different CTAB concentrations on tin ECM under different bias voltages was evaluated using in situ electrochemical and optical techniques, as well as ex situ characterizations. Results showed that CTAB can effectively inhibit tin ECM, and CTAB affected the electrodeposition during tin ECM by selective adsorption. Mechanisms were proposed to explain the beneficial role of CTAB. [ABSTRACT FROM AUTHOR]

• Effective and low-consumption finishing strategy for multifunctional stainless steel mesh and sponges. • Superhydrophobic coating with micro/nano structures is rationally constructed without organic solvents. • Rational water-based aza-Michael addition reaction coating strategy realizes on-demand special wettability. Superhydrophobic porous materials are widely used in oil-water separation due to their water-blocking and oil-passing properties. However, the preparation of most superhydrophobic porous materials is generally energy-intensive and must be performed using organic solvents. In this study, we describe a straightforward and cost-effective strategy for fabricating superhydrophobic coatings on nanosized soil particle-modified stainless steel mesh (SSM). The coating is prepared via the aza-Michael reaction of stearyl acrylate and melamine-urea–formaldehyde (MUF) resin catalysed by methyl cyclodextrin in water. Superhydrophobic meshes with water contact angles (WCAs) exceeding 150° are obtained, exhibiting extraordinary water repellency. The superhydrophobic mesh also effectively prevents surface contamination, creating a self-cleaning surface that is both waterproof and dustproof. Most importantly, the superhydrophobic mesh presents excellent oil separation performance for oil-water mixtures of various compositions, maintaining extremely high separation efficiency (>98%) even after 80 cycles. Additionally, we successfully apply this strategy to the preparation of superhydrophobic melamine sponges with excellent oil adsorption capacity (17.6–44.2 g/g). This innovative study provides an effective strategy for designing biomimetic superhydrophobic surfaces and is a promising development in the field of environmentally friendly oil-water separators. [ABSTRACT FROM AUTHOR]

The effect of tri-sodium citrate dehydrate on the electrochemical migration of tin in thin electrolyte layers containing chloride ions was investigated through potentiodynamic polarization, cyclic voltammetry, scanning electron microscopy, X-ray photoelectron spectroscopy, and optical techniques. The effects of applied bias voltage and concentration of citrate ions were also studied. Results showed that tri-sodium citrate dehydrate acts as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of tin citrate complexes. The mechanisms involved were proposed to explain the inhibition effect. [ABSTRACT FROM AUTHOR]

A superhydrophobic coating composed of epoxy on the bottom and siloxane-modified silica on the top was prepared by employing the scraping and spraying methods. The superhydrophobic coating possesses excellent mechanical properties, is superhydrophobic (water contact angle, WCA = 164.3°), and has low adhesion. The long-term corrosion resistance of the epoxy coating and the superhydrophobic coating in a 3.5 % NaCl solution and hydrogen sulfide environment was assessed using electrochemical impedance spectroscopy (EIS), polarization curve analysis, immersion testing, and X-ray diffraction (XRD). Test results indicate that the superhydrophobic coating has excellent anti-corrosion capability in an H 2 S environment for 50 days and in a 3.5 % NaCl solution for 60 days. This is of great significance for developing the potential applications of superhydrophobic coatings in H 2 S environments. [Display omitted] • Epoxy resin and superhydrophobic surface combination for carbon steel substrate protection. • The coating showed anticorrosive effect in 3.5 % sodium chloride solution. • Superhydrophobic surface has excellent corrosion resistance in H 2 S environment of alternating temperatures and humidities. [ABSTRACT FROM AUTHOR]

A smart-sensing coating is developed by adding a dual-emission fluorescent zirconium metal-organic framework/rhodamine B composite (Zr-MOF@RhB) into the commercial epoxy resin coating, which can autonomously detect and distinguish the damage of surface coating and the corrosion of substrate aluminum. The orange-yellow fluorescence can be observed to identify the area of mild coating damage without metal corrosion, resulting from the cumulative release of Zr-MOF@RhB with the emission wavelength of 583 nm. In case of the occurrence of aluminum corrosion, the fluorescence color turns from orange-yellow to green, in which the emission behavior of Zr-MOF@RhB at 490 nm is greatly enhanced with the presence of Al3+ ions. The smart-sensing ability can availably and robustly operate in the conditions of long term, wide ranges of pH and temperature, and diverse interfering substances. This simple and powerful warning system relying on fluorescent MOFs would not only extend the practical applications of MOFs but also be a promising candidate for smart coating strategies. • A fluorescent MOF composite is prepared for a smart-sensing coating. • The MOF composite exhibits robust fluorescent property for sensing Al3+. • The smart-sensing coating can warn coating damage and aluminum corrosion. [ABSTRACT FROM AUTHOR]

The soybean extract (SE) was firstly investigated for corrosion inhibition characteristics on carbon steel in sulfuric medium. The weight loss and electrochemical methods were used to research the inhibition performance and adsorption properties of SE in combination with halide ions. Results showed the SE + I- inhibitors possessed outstanding corrosion inhibition efficiency, ~98%. Furthermore, the effective compound of SE was identified to be responsible for the corrosion inhibition effect. The AFM, water contact angle and XPS measurements confirm the formation of a corrosion inhibitor film on carbon steel. Combining differential capacitance curves, corrosion inhibition mechanism was further interpreted. Good inhibition efficiency, green extract solvent, facile extraction procedure, high yield and environment sustainability, endow SE as novel corrosion inhibitor with a promising future for industrial application. ● Soybean extract (SE) was firstly utilized as an eco-friendly, promising corrosion inhibitor. ● SE exhibited excellent inhibition efficiency (~98%) in combination with I- for carbon steel in sulfuric solution. ● Characteristic adsorption of I- would make for protonated SE adsorption on positively charged carbon steel surface. [ABSTRACT FROM AUTHOR]

• PPy nanowires (NWs) suffer attacks easily to lose most doing anions in CV cycles. • PPy NWs' flexibility buffers volume change to avoid pulverization in CV cycles. • PPy NWs degrade uniformly, forming degraded surface layer and damaged areas. • PPy NWs' initial over-oxidation and dissolved O 2 in media worsen cycle stability. Polypyrrole (PPy) nanowires are widely used in supercapacitors due to their high faradaic pseudo-capacitance and specific surface areas. However, their rapid capacitance degradation is a key and broad issue that cannot be ignored. In this work, PPy/p-toluenesulfonate nanowires (PPy/pTS NWs) network films were electro-polymerized with different nanowire diameters (D) and film thicknesses (L). The effects of nanowire structure and the dissolved O 2 (DO) in the media on the capacitance degradation behavior were investigated. With the cyclic voltammetry (CV) cycles increasing, the surface layer of PPy/pTS NWs was gradually damaged and dissolved with the loss of most doping anions, resulting in decreased specific capacitance. The high initial over-oxidation degree of PPy/pTS NWs and the high DO concentration significantly accelerated the degradation of PPy/pTS NWs during CV cycles. After the loss of most capacitance, PPy/pTS NWs network films were expanded with increased L but reduced D , displaying uniform degradation without fractured nanowires. The capacitance stability of PPy/pTS NWs could be enhanced by lowering the initial over-oxidation degree, inhibiting the loss of doping anions, and removing DO in the media. [ABSTRACT FROM AUTHOR]