The effect of two alkylpyridinium ionic liquids （py-iLs） including N-butylpyridinium hydrogen sulfate （BpyHSO4） and N-hexylpyridinium hydrogen sulfate （HpyHSO4） on the kinetics of copper electrodeposition from a...The effect of two alkylpyridinium ionic liquids （py-iLs） including N-butylpyridinium hydrogen sulfate （BpyHSO4） and N-hexylpyridinium hydrogen sulfate （HpyHSO4） on the kinetics of copper electrodeposition from acidic sulfate solution was investigated by cyclic voltammetry and potentiodynamic polarization measurements. Results from cyclic voltammetry indicate that these py-iLs have a pronounced inhibiting effect on CuE＋ electroreduction and there exists a typical nucleation and growth process. Kinetic parameters such as Tafel slope, transfer coefficient and exchange current density obtained from Tafel plots, lead to the conclusion that py-iLs inhibit the charge transfer by slightly changing the copper electrodeposition mechanism through their adsorption on the cathodic surface. In addition, scanning electron microscope （SEM） and X-ray diffraction analyses reveal that the presence of these additives leads to more leveled and fine-grained cathodic deposits without changing the crystal structure of the electrodeposited copper but strongly affects the crystallographic orientation by significantly inhibiting the growth of （111）, （200） and （311） planes.展开更多
Ruthenium-based catalyst is one of the most active catalysts for oxygen evolution reaction(OER)in acid media.However,the strong bonding between the Ru sites and oxygen intermediates leads to high overpotential to trig...Ruthenium-based catalyst is one of the most active catalysts for oxygen evolution reaction(OER)in acid media.However,the strong bonding between the Ru sites and oxygen intermediates leads to high overpotential to trigger the OER process.Hence,pyrochlore rare-earth ruthenate(RE_(2)-Ru_(2)O_(7))structures with a series of rare-earth elements(Nd,Sm,Gd,Er,and Yb)were constructed to tune the electronic structure of the Ru sites.Surface structure analysis indicated that the increase of the radius of the rare-earth cations resulted in higher content of defective oxygen(the percentage of the defective oxygen increased from 29.5% to 49.7%) in the RE_(2)Ru_(2)O_(7) structure due to the weakened hybridization of the Ru-O bond.This reduced the valence states of the Ru sites and enlarged the gap between the 4d band center and the Fermi level(E_(F))of Ru,resulting in the weakened adsorption of oxygen intermediates and the improved OER performance in acid media.Among the as-prepared ruthenium pyrochlores,Nd_(2)Ru_(2)O_(7) displayed the lowest OER onset overpotential(210 mV)and Tafel slope(58.48 mV dec^(-1)),as well as 30 times higher intrinsic activity and much higher durability than the state-of-art RuO_(2) catalyst.展开更多
基金Projects(51204080, 51274108) supported by the National Natural Science Foundation of ChinaProject(2011FA009) supported by the Natural Science Foundation of Yunnan Province, ChinaProject(2011FZ020) supported by the Application Research Foundation of Yunnan Province, China
文摘The effect of two alkylpyridinium ionic liquids （py-iLs） including N-butylpyridinium hydrogen sulfate （BpyHSO4） and N-hexylpyridinium hydrogen sulfate （HpyHSO4） on the kinetics of copper electrodeposition from acidic sulfate solution was investigated by cyclic voltammetry and potentiodynamic polarization measurements. Results from cyclic voltammetry indicate that these py-iLs have a pronounced inhibiting effect on CuE＋ electroreduction and there exists a typical nucleation and growth process. Kinetic parameters such as Tafel slope, transfer coefficient and exchange current density obtained from Tafel plots, lead to the conclusion that py-iLs inhibit the charge transfer by slightly changing the copper electrodeposition mechanism through their adsorption on the cathodic surface. In addition, scanning electron microscope （SEM） and X-ray diffraction analyses reveal that the presence of these additives leads to more leveled and fine-grained cathodic deposits without changing the crystal structure of the electrodeposited copper but strongly affects the crystallographic orientation by significantly inhibiting the growth of （111）, （200） and （311） planes.
基金supported by the National Key Research and Development Project(2018YFB1502401)the National Natural Science Foundation of China(21771018 and 21875004)+3 种基金the Royal Society and Newton Fund through Newton Advanced Fellowship award(NAF\R1\191294)the Program for Changjiang Scholars and Innovation Research Team in the University(IRT1205)the Fundamental Research Funds for the Central Universitiesthe long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of China。
文摘Ruthenium-based catalyst is one of the most active catalysts for oxygen evolution reaction(OER)in acid media.However,the strong bonding between the Ru sites and oxygen intermediates leads to high overpotential to trigger the OER process.Hence,pyrochlore rare-earth ruthenate(RE_(2)-Ru_(2)O_(7))structures with a series of rare-earth elements(Nd,Sm,Gd,Er,and Yb)were constructed to tune the electronic structure of the Ru sites.Surface structure analysis indicated that the increase of the radius of the rare-earth cations resulted in higher content of defective oxygen(the percentage of the defective oxygen increased from 29.5% to 49.7%) in the RE_(2)Ru_(2)O_(7) structure due to the weakened hybridization of the Ru-O bond.This reduced the valence states of the Ru sites and enlarged the gap between the 4d band center and the Fermi level(E_(F))of Ru,resulting in the weakened adsorption of oxygen intermediates and the improved OER performance in acid media.Among the as-prepared ruthenium pyrochlores,Nd_(2)Ru_(2)O_(7) displayed the lowest OER onset overpotential(210 mV)and Tafel slope(58.48 mV dec^(-1)),as well as 30 times higher intrinsic activity and much higher durability than the state-of-art RuO_(2) catalyst.
