To clarify the anodic dissolution mechanism of Mg,the hydrogen evolution from pure Mg in acidic solutions under galvanostatic conditions were systematically measured.With increasing anodic current density,the cathodic...To clarify the anodic dissolution mechanism of Mg,the hydrogen evolution from pure Mg in acidic solutions under galvanostatic conditions were systematically measured.With increasing anodic current density,the cathodic hydrogen evolution rate decreased,and the anodic hydrogen evolution became faster while some surface area on the Mg was becoming dark under anodic polarization.Based on the surface analysis results and the generally accepted basic electrochemical equations,the evolution kinetics of hydrogen from Mg was deduced,and the most possible surface intermediate active species that could facilitate the anodic Mg dissolution and anodic hydrogen evolution were proposed.This paper further develops the model of incomplete film Mg^(+) dissolution,explains many reported experimental phenomena,and clarifies misunderstandings of current mechanism.展开更多
Hydrogen evolution is normally associated with the corrosion or dissolution of Mg alloys in aqueous solutions.This work studied the corrosion behavior of sputtered pure Mg,Mg82Zn18(at.%),Mg64Zn36(at.%),and pure Zn in ...Hydrogen evolution is normally associated with the corrosion or dissolution of Mg alloys in aqueous solutions.This work studied the corrosion behavior of sputtered pure Mg,Mg82Zn18(at.%),Mg64Zn36(at.%),and pure Zn in 3.5%Na Cl solution.Mg64Zn36had(ⅰ)an amorphous microstructure with some nano-scale grains,(ⅱ)a corrosion rate substantially lower than that of pure Mg,and(ⅲ)no hydrogen evolution during corrosion or anodic dissolution,because the positive corrosion potential retarded the cathodic hydrogen evolution.This is a new route to prevent hydrogen evolution during Mg corrosion,which has never previously been realized.展开更多
It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can norma...It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can normally be significantly accelerated by bacterial activity. However,this paper reports on the corrosion of highly active Mg interestingly inhibited by an algal-symbiotic bacterium Bacillus altitudinis. The corrosion of Mg in the presence of the bacterium drastically reduced by one order of magnitude after 14 days of immersion. This means that the algal-symbiotic bacterium widely available in natural ocean environments may be employed as a green and sustainable inhibitor in the marine industry. Based on electrochemical measurements, surface analyses and microbe experiments, a combined inhibition mechanism is proposed in the paper to interpret the interesting corrosion behavior of Mg.展开更多
Controllable and scalable preparation of electrocatalyst materials holds significant importance for their practical application.Magnetron sputtering is a highly effective synthesis method,known for its producing unifo...Controllable and scalable preparation of electrocatalyst materials holds significant importance for their practical application.Magnetron sputtering is a highly effective synthesis method,known for its producing uniform films and allowing easy control of component compositions.In this paper,we propose an in-situ synthesis method for layered double hydroxide(LDH)electrocatalysts through sacrificing magnetron sputtered films.The resulting FeCo-LDH catalyst demonstrated a low overpotential of only 300 mV at 10 mA·cm^(-2).Furthermore,we conducted spectroscopic analysis to investigate the surface changes of the catalysts during the oxygen evolution reaction(OER)process.Our findings indicated that the formation of Co oxyhydroxides plays a beneficial role in enhancing the catalytical performance of the FeCo-LDH for OER reaction.This restructuring strategy of converting a magnetron-sputtered sacrificial film into a catalytical LDH introduces a new avenue to the synthesis of transition metal-based electrocatalysts.展开更多
The anode activity can to a great degree limit the cathodic hydrogen evolution efficiency in an electrolyte cell.Thus,cost-efficient electrocatalysts with good water oxidation performance and stability are highly desi...The anode activity can to a great degree limit the cathodic hydrogen evolution efficiency in an electrolyte cell.Thus,cost-efficient electrocatalysts with good water oxidation performance and stability are highly desired in widespread implementation of the hydrogen production from water splitting.This paper proposes a facile corrosion-reconstruction strategy to transform Fe surface into a Fe-Co hydroxide layer to improve the oxygen evolution activity.The as-prepared catalyst was measured to have an over-potentential as low as 320 mV at 100 mA·cm^(−2),and its stability even exceeded 600 h.Surface and Raman spectroscopy analyses indicated that the catalyst experienced chemical changes from hydroxides to oxyhydroxides and Co^(2+)to Co^(3+)during oxygen evolution reaction(OER).The corrosion-reconstruction is not only an economical method to synthesize a highly efficient,stable and durable Fe-based catalysts,it also converses the detrimental corrosion into a beneficial catalyst fabrication process.展开更多
A novel coating on the Mg1Mn alloy was produced by anodic polarization combined with hydrothermal treatment(AP+H)in 0.1 M Na2CO3 solution.The microstructure and protection of the coating were evaluated.The coating con...A novel coating on the Mg1Mn alloy was produced by anodic polarization combined with hydrothermal treatment(AP+H)in 0.1 M Na2CO3 solution.The microstructure and protection of the coating were evaluated.The coating consisted of MgCO3,Mg(OH)2 and MgO,and provided satisfactory protection in 3.5 wt%NaCl with a corrosion rate of 0.07 mm y−1 in 72 h.However,after that period,the corrosion rate of the specimen increased due to the damage of the coating.The failure of the coating was strongly related to the second phase particles(e.g.Zr particles)or impurities in the matrix.The AP+H coating is supposed to be used as a primer coating for Mg applications in kitchen ware,biomedical areas or industry.展开更多
Layered double hydroxide(LDH) has been widely developed in the field of corrosion and protection in recent years based on its unique characteristics including anion capacity, anion exchange ability, structure memory e...Layered double hydroxide(LDH) has been widely developed in the field of corrosion and protection in recent years based on its unique characteristics including anion capacity, anion exchange ability, structure memory effect, and barrier resistance. This paper comprehensively reviews recent work on the preparations, properties of LDH in the forms of powder and film and their applications in different environments in corrosion and protection. Some novel perspectives are also proposed at the end of the review for future research in corrosion and protection field.展开更多
Mg atmospheric corrosion is induced by a thin surface aqueous layer. Controlling factors are microgalvanic acceleration between different phases, protection by a continuous second phase distribution, protection by cor...Mg atmospheric corrosion is induced by a thin surface aqueous layer. Controlling factors are microgalvanic acceleration between different phases, protection by a continuous second phase distribution, protection by corrosion products, and degradation of protective layers by aggressive species such as chloride ions. The Mg atmospheric corrosion rate increases with relative humidity (RH) and concentrations of aggressive species. Temperature increases the corrosion rate unless a protective film causes a decrease.O2, SO2 and NO2 accelerate the atmospheric corrosion rate, whereas the corrosion rate is decreased by CO2. The traditional gravimetric method can evaluate effectively the corrosion behavior of Mg alloys.展开更多
High strength-to-weight ratio, commendable biocompatibility and excellent corrosion resistance make Ti alloys widely applicable in aerospace, medical and marine industries. However, these alloys suffer from serious bi...High strength-to-weight ratio, commendable biocompatibility and excellent corrosion resistance make Ti alloys widely applicable in aerospace, medical and marine industries. However, these alloys suffer from serious biofouling, and may become vulnerable to corrosion attack under some extreme marine conditions. The passivating and biofouling performance of Ti alloys can be attributed to their compact, stable and protective films. This paper comprehensively reviews the passivating and biofouling behavior, as well as their mechanisms, for typical Ti alloys in various marine environments. This review aims to help extend applications of Ti alloys in extremely harsh marine conditions.展开更多
The assemblages of unicellular microalgae and bacteria in phytoplankton communities can generally result in biodeterioration of metals in marine environment.In this study,the self-promoted biofouling mechanism underne...The assemblages of unicellular microalgae and bacteria in phytoplankton communities can generally result in biodeterioration of metals in marine environment.In this study,the self-promoted biofouling mechanism underneath red-tide alga Phaeodactylum tricornutum and its symbiotic bacterium Bacillus altitudinis was systematically revealed.The mutualistic interaction of the bacteria and algae quadrupled the corrosion rate in comparison to the individual effect of the bacterium or algal strain alone.Reversely,the corroded metal appeared to be an accelerator that can stimulate the activity of the P.tricornutum and aggravate the biological pollution based on the result of 62.3%up-regulation of the key photosynthesis genes.The corrosion-biofouling-accelerated corrosion-deteriorated biofouling formed a vicious cycle.展开更多
基金supported by the National Science Foundation of China(key project grant No.51731008 and general project grant No.51671163).
文摘To clarify the anodic dissolution mechanism of Mg,the hydrogen evolution from pure Mg in acidic solutions under galvanostatic conditions were systematically measured.With increasing anodic current density,the cathodic hydrogen evolution rate decreased,and the anodic hydrogen evolution became faster while some surface area on the Mg was becoming dark under anodic polarization.Based on the surface analysis results and the generally accepted basic electrochemical equations,the evolution kinetics of hydrogen from Mg was deduced,and the most possible surface intermediate active species that could facilitate the anodic Mg dissolution and anodic hydrogen evolution were proposed.This paper further develops the model of incomplete film Mg^(+) dissolution,explains many reported experimental phenomena,and clarifies misunderstandings of current mechanism.
基金supported by National Natural Science Foundation of China No.51801168 and No.51731008Natural Science Foundation of Fujian Province No.2018J05093。
文摘Hydrogen evolution is normally associated with the corrosion or dissolution of Mg alloys in aqueous solutions.This work studied the corrosion behavior of sputtered pure Mg,Mg82Zn18(at.%),Mg64Zn36(at.%),and pure Zn in 3.5%Na Cl solution.Mg64Zn36had(ⅰ)an amorphous microstructure with some nano-scale grains,(ⅱ)a corrosion rate substantially lower than that of pure Mg,and(ⅲ)no hydrogen evolution during corrosion or anodic dissolution,because the positive corrosion potential retarded the cathodic hydrogen evolution.This is a new route to prevent hydrogen evolution during Mg corrosion,which has never previously been realized.
基金the National Natural Science Foundation of China (Nos.51731008,52250710159,51671163,51901198)the National Key Research and Development Program of China (No.2017YFB0702100)。
文摘It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can normally be significantly accelerated by bacterial activity. However,this paper reports on the corrosion of highly active Mg interestingly inhibited by an algal-symbiotic bacterium Bacillus altitudinis. The corrosion of Mg in the presence of the bacterium drastically reduced by one order of magnitude after 14 days of immersion. This means that the algal-symbiotic bacterium widely available in natural ocean environments may be employed as a green and sustainable inhibitor in the marine industry. Based on electrochemical measurements, surface analyses and microbe experiments, a combined inhibition mechanism is proposed in the paper to interpret the interesting corrosion behavior of Mg.
基金support from the National Natural Science Foundation of China(Nos.52250710159,51731008,51671163)。
文摘Controllable and scalable preparation of electrocatalyst materials holds significant importance for their practical application.Magnetron sputtering is a highly effective synthesis method,known for its producing uniform films and allowing easy control of component compositions.In this paper,we propose an in-situ synthesis method for layered double hydroxide(LDH)electrocatalysts through sacrificing magnetron sputtered films.The resulting FeCo-LDH catalyst demonstrated a low overpotential of only 300 mV at 10 mA·cm^(-2).Furthermore,we conducted spectroscopic analysis to investigate the surface changes of the catalysts during the oxygen evolution reaction(OER)process.Our findings indicated that the formation of Co oxyhydroxides plays a beneficial role in enhancing the catalytical performance of the FeCo-LDH for OER reaction.This restructuring strategy of converting a magnetron-sputtered sacrificial film into a catalytical LDH introduces a new avenue to the synthesis of transition metal-based electrocatalysts.
基金support from the National Natural Science Foundation of China(key project Grant No.51731008 and general project Grant No.51671163).
文摘The anode activity can to a great degree limit the cathodic hydrogen evolution efficiency in an electrolyte cell.Thus,cost-efficient electrocatalysts with good water oxidation performance and stability are highly desired in widespread implementation of the hydrogen production from water splitting.This paper proposes a facile corrosion-reconstruction strategy to transform Fe surface into a Fe-Co hydroxide layer to improve the oxygen evolution activity.The as-prepared catalyst was measured to have an over-potentential as low as 320 mV at 100 mA·cm^(−2),and its stability even exceeded 600 h.Surface and Raman spectroscopy analyses indicated that the catalyst experienced chemical changes from hydroxides to oxyhydroxides and Co^(2+)to Co^(3+)during oxygen evolution reaction(OER).The corrosion-reconstruction is not only an economical method to synthesize a highly efficient,stable and durable Fe-based catalysts,it also converses the detrimental corrosion into a beneficial catalyst fabrication process.
基金supported by the National Natural Science Foundation of China(No.51801168).
文摘A novel coating on the Mg1Mn alloy was produced by anodic polarization combined with hydrothermal treatment(AP+H)in 0.1 M Na2CO3 solution.The microstructure and protection of the coating were evaluated.The coating consisted of MgCO3,Mg(OH)2 and MgO,and provided satisfactory protection in 3.5 wt%NaCl with a corrosion rate of 0.07 mm y−1 in 72 h.However,after that period,the corrosion rate of the specimen increased due to the damage of the coating.The failure of the coating was strongly related to the second phase particles(e.g.Zr particles)or impurities in the matrix.The AP+H coating is supposed to be used as a primer coating for Mg applications in kitchen ware,biomedical areas or industry.
基金financially supported by the State Key Project of Research and Development (No. 2016YFC1100300)the National Natural Science Foundation of China (No. 21203158, 21773199, and 21621091)。
文摘Layered double hydroxide(LDH) has been widely developed in the field of corrosion and protection in recent years based on its unique characteristics including anion capacity, anion exchange ability, structure memory effect, and barrier resistance. This paper comprehensively reviews recent work on the preparations, properties of LDH in the forms of powder and film and their applications in different environments in corrosion and protection. Some novel perspectives are also proposed at the end of the review for future research in corrosion and protection field.
基金supported by the National Natural Science Foundation of China (No. 51731008)the National Environmental Corrosion Platform of China
文摘Mg atmospheric corrosion is induced by a thin surface aqueous layer. Controlling factors are microgalvanic acceleration between different phases, protection by a continuous second phase distribution, protection by corrosion products, and degradation of protective layers by aggressive species such as chloride ions. The Mg atmospheric corrosion rate increases with relative humidity (RH) and concentrations of aggressive species. Temperature increases the corrosion rate unless a protective film causes a decrease.O2, SO2 and NO2 accelerate the atmospheric corrosion rate, whereas the corrosion rate is decreased by CO2. The traditional gravimetric method can evaluate effectively the corrosion behavior of Mg alloys.
文摘High strength-to-weight ratio, commendable biocompatibility and excellent corrosion resistance make Ti alloys widely applicable in aerospace, medical and marine industries. However, these alloys suffer from serious biofouling, and may become vulnerable to corrosion attack under some extreme marine conditions. The passivating and biofouling performance of Ti alloys can be attributed to their compact, stable and protective films. This paper comprehensively reviews the passivating and biofouling behavior, as well as their mechanisms, for typical Ti alloys in various marine environments. This review aims to help extend applications of Ti alloys in extremely harsh marine conditions.
基金The support of the National Key Research and Development Program of China(No.2017YFB0702100)the National Natural Science Foundation of China(key project No.51731008,general project Nos.51671163,51901198)。
文摘The assemblages of unicellular microalgae and bacteria in phytoplankton communities can generally result in biodeterioration of metals in marine environment.In this study,the self-promoted biofouling mechanism underneath red-tide alga Phaeodactylum tricornutum and its symbiotic bacterium Bacillus altitudinis was systematically revealed.The mutualistic interaction of the bacteria and algae quadrupled the corrosion rate in comparison to the individual effect of the bacterium or algal strain alone.Reversely,the corroded metal appeared to be an accelerator that can stimulate the activity of the P.tricornutum and aggravate the biological pollution based on the result of 62.3%up-regulation of the key photosynthesis genes.The corrosion-biofouling-accelerated corrosion-deteriorated biofouling formed a vicious cycle.