Metal-free electrocatalysts for the oxygen evolution reaction(OER)are gaining attention for their low cost,high conductivity,and moderate catalytic performance.While trace metal interference in assynthesized catalysts...Metal-free electrocatalysts for the oxygen evolution reaction(OER)are gaining attention for their low cost,high conductivity,and moderate catalytic performance.While trace metal interference in assynthesized catalysts has been ruled out,the impact of trace metal contamination during electrochemical activation remains unexplored.This study demonstrates that anodic pretreatment in alkaline electrolytes enhances the catalytic performance of carbon cloth.Specifically,carbon cloth activated in 8 mol/L Na OH achieves a current density of 10 m A/cm^(2)with an overpotential of only 338 m V,comparable to metalbased OER catalysts.Electrochemical and spectroscopic analyses show the deposition of Fe Ni O_(x)H_(y)oxyhydroxides(0.19±0.06μg/cm^(2))on specific sites of the carbon substrate during activation.These nanoparticles contribute significantly to the catalytic activity,with a synergistic effect between Fe Ni O_(x)H_(y)and the carbon substrate.The turnover frequency(TOF)for Fe correlates with the amount of C=O groups on the carbon substrate,providing evidence for an interfacial synergistic effect.This work emphasizes the importance of considering trace metal effects in metal-free catalyst evaluation and offers insights for the design of more efficient carbon-based hybrid OER catalysts.展开更多
The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, e...The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, electrochemical impedance spectroscopy（EIS） and corrosion rate obtained in an acidic zinc sulfate electrolyte solution. Scanning electron microscopy（SEM）, X-ray diffraction（XRD）, and energy dispersive X-ray spectroscopy（EDXS） were used to observe the microstructural features of coating. Anodes of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-ZrO2, and Pb-1%Ag anodes were also researched. The results indicated that the Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 showed the best catalytic activity and corrosion resistant performance; the intensity of diffraction peak exhibited the highest value as well as a new PbWO4 phase; the content of WC and ZrO2 in coating showed the highest value as well as the finest grain size.展开更多
The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on acti...The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.展开更多
基金Funding from the U.S.Army Research Laboratory under agreement No.W911NF-14–2–0005 with Dr.Joe Labukas as project manager supported co-author JMFFunding by the Office of Naval Research grant No.N000141210967 with Dr.David A.Shifler as scientific officer supported co-author LGBThe Bruker Dimension Icon AFM utilized in this work is located in the Boise State University Surface Science Laboratory(SSL),which is part of the FaCT Core Facility,RRID:SCR_024733,that receives support from the National Institutes of Health under the Institutional Development Awards Program of the National Institute of General Medical Sciences via grants#P20GM148321 and P20GM103408,the former of which also partially supports co-authors CME and PHD.
基金financially supported by the National Natural Science Foundation of China(No.22479097)the Shanghai Science and Technology Committee(Nos.23ZR1433000 and 22511100400)+1 种基金the National High-Level Talent Program for Young Scholarsthe Start-up Fund(F.Song)from Shanghai Jiao Tong University。
文摘Metal-free electrocatalysts for the oxygen evolution reaction(OER)are gaining attention for their low cost,high conductivity,and moderate catalytic performance.While trace metal interference in assynthesized catalysts has been ruled out,the impact of trace metal contamination during electrochemical activation remains unexplored.This study demonstrates that anodic pretreatment in alkaline electrolytes enhances the catalytic performance of carbon cloth.Specifically,carbon cloth activated in 8 mol/L Na OH achieves a current density of 10 m A/cm^(2)with an overpotential of only 338 m V,comparable to metalbased OER catalysts.Electrochemical and spectroscopic analyses show the deposition of Fe Ni O_(x)H_(y)oxyhydroxides(0.19±0.06μg/cm^(2))on specific sites of the carbon substrate during activation.These nanoparticles contribute significantly to the catalytic activity,with a synergistic effect between Fe Ni O_(x)H_(y)and the carbon substrate.The turnover frequency(TOF)for Fe correlates with the amount of C=O groups on the carbon substrate,providing evidence for an interfacial synergistic effect.This work emphasizes the importance of considering trace metal effects in metal-free catalyst evaluation and offers insights for the design of more efficient carbon-based hybrid OER catalysts.
基金Funded by the National Natural Science Foundation of China(Nos.51564029,51504111,51504231,51364019)the Key Project of Yunnan Province Applied Basic Research Plan of China(No.2014FA024)
文摘The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, electrochemical impedance spectroscopy（EIS） and corrosion rate obtained in an acidic zinc sulfate electrolyte solution. Scanning electron microscopy（SEM）, X-ray diffraction（XRD）, and energy dispersive X-ray spectroscopy（EDXS） were used to observe the microstructural features of coating. Anodes of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-ZrO2, and Pb-1%Ag anodes were also researched. The results indicated that the Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 showed the best catalytic activity and corrosion resistant performance; the intensity of diffraction peak exhibited the highest value as well as a new PbWO4 phase; the content of WC and ZrO2 in coating showed the highest value as well as the finest grain size.
基金Project(5227010679)supported by the National Natural Science Foundation of China。
文摘The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.
