Iron oxide nanoparticles（FeOx NPs, 5–30 nm size） prepared via laser ablation in liquid were supported onto Indium Tin Oxide conductive glass slides by magnetophoretic deposition（MD） technique. The resulting Fe O ...Iron oxide nanoparticles（FeOx NPs, 5–30 nm size） prepared via laser ablation in liquid were supported onto Indium Tin Oxide conductive glass slides by magnetophoretic deposition（MD） technique. The resulting Fe O x@ITO electrodes are characterized by a low amount of iron coverage of 16–50 nmol/cm^2,and show electrocatalytic activity towards water oxidation in neutral phosphate buffer pH 7 with 0.58 V overpotential and quantitative Faradaic efficiency towards oxygen production. XPS analysis on the oxygen region of the FeOx films reveals a substantial hydration of the surface after catalysis, recognized as a crucial step to access reactivity.展开更多
Development of Earth-abundant oxygen evolution reaction(OER)electrocatalysts with high performance is essential for the practical application of hydrogen energy.Herein,we report a high-efficiency electrocatalyst for e...Development of Earth-abundant oxygen evolution reaction(OER)electrocatalysts with high performance is essential for the practical application of hydrogen energy.Herein,we report a high-efficiency electrocatalyst for electrochemical water oxidation based on an Ni-MOF nanosheet array on Ni foam(Ni-MOF/NF).In 1.0 M KOH,this Ni-MOF/NF catalyst drives 100 mA cm^(−2)at an overpotential of 320 mV.展开更多
Urea oxidation reaction(UOR)electrocatalysis,a promising anodic reaction with lower overpotentials than the oxygen evolution reaction,can work in tandem with many cathodic reactions to improve energy-conversion effici...Urea oxidation reaction(UOR)electrocatalysis,a promising anodic reaction with lower overpotentials than the oxygen evolution reaction,can work in tandem with many cathodic reactions to improve energy-conversion efficiencies.Among other catalysts,single-atom catalysts(SACs)possess immense potential as high-performance and low-cost catalysts towards UOR,owing to their numerous advantages such as metal-utilization efficiency and low-coordination metal sites.Nevertheless,systematic studies remain unexplored for the local coordination structures of SACs regulating their UOR pathways,which severely impedes further performance advancement.Here,we aim to construct the mechanistic picture of UOR pathways on SACs,using two nickel-single-atom enriched conjugated coordination polymers(named Ni-N-CP and Ni-O-CP)with well-defined NiN_(4)and NiO4 coordination structures for the proof-of-concept studies.The Ni-O-CP exhibits exceptional UOR performance with a turnover frequency of 0.51 s^(-1),significantly outperforming the Ni-N-CP(0.38 s^(-1))and other state-of-the-art SACs towards UOR.Our theoretical calculations combined with in-situ Fourier transform infrared and ultraviolet-visible spectroscopy measurements elucidate that two UOR pathways towards NO_(2)^(-)and N_(2)products were identified,which critically depends on the participation of the as-generated ammonia species in the UOR process.This work provides insights for regulating the activity and selectivity of UOR electrocatalysis.展开更多
Surfactant removal from the surface of platinum-based nanoparticles prepared using solution-based methods is a prerequisite to realize their high catalytic performance for electrochemical reactions. Herein, we report ...Surfactant removal from the surface of platinum-based nanoparticles prepared using solution-based methods is a prerequisite to realize their high catalytic performance for electrochemical reactions. Herein, we report an effective approach combining acetic acid refluxing with an electrochemical process for the removal of amine- or thiol-based capping agents from the surface of supported-platinum nanoparticles. This strategy involves surfactant protonation by refluxing the supported-platinum particles in acetic acid followed by surfactant removal by subsequent electrochemical treatment at high potential. We demon- strate that this combined activation process is essential to enhance platinum particle performance in catalyzing direct methanol fuel cell reactions, including methanol oxidation and oxygen reduction reac- tions. The studies in this work show promise in electrocatalysis applications of solution-based materials synthesis.展开更多
基金supported by the Italian Ministero dell’Università e della Ricerca (MIUR), (FIRB RBAP11C58Y, "Nano Solar" and PRIN 2010 "Hi-Phuture")COST action CM1205 "CARISMA: CAtalytic Rout Ines for Small Molecule Activation"
文摘Iron oxide nanoparticles（FeOx NPs, 5–30 nm size） prepared via laser ablation in liquid were supported onto Indium Tin Oxide conductive glass slides by magnetophoretic deposition（MD） technique. The resulting Fe O x@ITO electrodes are characterized by a low amount of iron coverage of 16–50 nmol/cm^2,and show electrocatalytic activity towards water oxidation in neutral phosphate buffer pH 7 with 0.58 V overpotential and quantitative Faradaic efficiency towards oxygen production. XPS analysis on the oxygen region of the FeOx films reveals a substantial hydration of the surface after catalysis, recognized as a crucial step to access reactivity.
文摘Development of Earth-abundant oxygen evolution reaction(OER)electrocatalysts with high performance is essential for the practical application of hydrogen energy.Herein,we report a high-efficiency electrocatalyst for electrochemical water oxidation based on an Ni-MOF nanosheet array on Ni foam(Ni-MOF/NF).In 1.0 M KOH,this Ni-MOF/NF catalyst drives 100 mA cm^(−2)at an overpotential of 320 mV.
基金supported by the National Natural Science Foundation of China(52373211)the China Postdoctoral Science Foundation(2023T160274,2021M690067).
文摘Urea oxidation reaction(UOR)electrocatalysis,a promising anodic reaction with lower overpotentials than the oxygen evolution reaction,can work in tandem with many cathodic reactions to improve energy-conversion efficiencies.Among other catalysts,single-atom catalysts(SACs)possess immense potential as high-performance and low-cost catalysts towards UOR,owing to their numerous advantages such as metal-utilization efficiency and low-coordination metal sites.Nevertheless,systematic studies remain unexplored for the local coordination structures of SACs regulating their UOR pathways,which severely impedes further performance advancement.Here,we aim to construct the mechanistic picture of UOR pathways on SACs,using two nickel-single-atom enriched conjugated coordination polymers(named Ni-N-CP and Ni-O-CP)with well-defined NiN_(4)and NiO4 coordination structures for the proof-of-concept studies.The Ni-O-CP exhibits exceptional UOR performance with a turnover frequency of 0.51 s^(-1),significantly outperforming the Ni-N-CP(0.38 s^(-1))and other state-of-the-art SACs towards UOR.Our theoretical calculations combined with in-situ Fourier transform infrared and ultraviolet-visible spectroscopy measurements elucidate that two UOR pathways towards NO_(2)^(-)and N_(2)products were identified,which critically depends on the participation of the as-generated ammonia species in the UOR process.This work provides insights for regulating the activity and selectivity of UOR electrocatalysis.
文摘Surfactant removal from the surface of platinum-based nanoparticles prepared using solution-based methods is a prerequisite to realize their high catalytic performance for electrochemical reactions. Herein, we report an effective approach combining acetic acid refluxing with an electrochemical process for the removal of amine- or thiol-based capping agents from the surface of supported-platinum nanoparticles. This strategy involves surfactant protonation by refluxing the supported-platinum particles in acetic acid followed by surfactant removal by subsequent electrochemical treatment at high potential. We demon- strate that this combined activation process is essential to enhance platinum particle performance in catalyzing direct methanol fuel cell reactions, including methanol oxidation and oxygen reduction reac- tions. The studies in this work show promise in electrocatalysis applications of solution-based materials synthesis.
