Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and superc...Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and supercapacitors.The 3D vertically orientated NiTe dendritic frameworks induce the homogeneous nucleation of 2D Ni_(x)Co_(12-x)Se nanosheet arrays along similar crystal directions and bring a strong interfacial binding between the integrated active components.In particular,the optimized Ni_(6)Co_(6)Se@NiTe with an interface coupling effect works in concert to tune the intrinsic activity.It only needs a low overpotential of 1.33 V to yield a current density of 10 mA cm^(-2)for alkaline urea electrolysis.Meanwhile,the full urea catalysis driven only by Ni_(6)Co_(6)Se@NiTe achieves 10 mA cm^(-2)at a potential of 1.38 V and can approach a constant level of the current response for 40 h.Besides,the integrated Ni_(6)Co_(6)Se@NiTe electrode delivers an enhanced specific capacity(223 mA h g^(-1)at 1 A g^(-1))with a high cycling stability.Consequently,a hybrid asymmetric supercapacitor(HASC)device based on Ni_(6)Co_(6)Se@NiTe exhibits a favorable rate capability and reaches a high energy density of 67.7 Wh kg^(-1)and a power density of 724.8 W kg^(-1)with an exceptional capacity retention of 92.4%after sequential 12000 cycles at 5 A g^(-1).展开更多
Deliberate modulation of the electronic structure via interface engineering is one of promising perspectives to build advanced catalysts for urea oxidation reaction(UOR)at high current densities.However,it still remai...Deliberate modulation of the electronic structure via interface engineering is one of promising perspectives to build advanced catalysts for urea oxidation reaction(UOR)at high current densities.However,it still remains some challenges originating from the intrinsically sluggish UOR dynamics and the high energy barrier for urea adsorption.In response,we report the coupled NiSe_(2)nanowrinkles with Ni_(5)P_(4)nanorods heterogeneous structure onto Ni foam(denoted as NiSe_(2)@Ni_(5)P_(4)/NF)through successive phosphorization and selenization strategy,in which the produced closely contacted interface could provide high-flux electron transfer pathways.Theoretical findings decipher that the fast charge transfer takes place at the interfacial region from Ni_(5)P_(4)to NiSe_(2),which is conducive to optimizing adsorption energy of urea molecules.As expected,the well-designed NiSe_(2)@Ni_(5)P_(4)/NF only requires the low potential of 1.402 V at the current density of 500 mA·cm^(-2).More importantly,a small Tafel slope of 27.6 mV·dec^(-1),a high turnover frequency(TOF)value of 1.037 s^(-1)as well as the prolonged stability of 950 h at the current density of 100 mA·cm^(-2)are also achieved.This study enriches the understanding on the electronic structure modulation via interface engineering and offers bright prospect to design advanced UOR catalysts.展开更多
The development of advanced electrocatalysts for electro-oxidation reactions has attracted much attention because of the critical role of such electrocatalysts in improving the overall efficiency of coupled hydrogen p...The development of advanced electrocatalysts for electro-oxidation reactions has attracted much attention because of the critical role of such electrocatalysts in improving the overall efficiency of coupled hydrogen production.We have developed an efficient lanthanum-dopedα-Ni(OH)_(2) bifunctional catalyst with a 1D-2D-3D hierarchical nanostructure.It shows superior activity and stability in the anodic oxygen evolution reaction(OER)and urea oxidation reaction(UOR).Enrichment of the edge sites and conducting La doping inα-Ni(OH)_(2) phase enable formation and stabilization of abundant local Ni^(3+)ions.This guarantees ultralow onset potentials in electro-oxidation reactions.The 1D-2D-3D hierarchical nanostructure significantly boosts the in situ generation of high-valence active species,which results in efficient and stable OER and UOR performances,and the synergistic merit of doping-induced facile reaction kinetics.Because of the structural benefits of a large surface area,charge-transfer promotion,good structural stability,and bifunctionality,a 1%La-dopedα-Ni(OH)_(2) hierarchical nanostructure gives superior OER and UOR performances with low overpotentials,large catalytic current densities,and excellent operational stability.It is therefore a promising catalyst for use in simultaneous alkaline wastewater treatment and hydrogen production.展开更多
The phase transformation of catalysts has been extensively observed in heterogeneous catalytic reactions that hinder the long cycling catalysis,and it remains a big challenge to precisely control the active phase duri...The phase transformation of catalysts has been extensively observed in heterogeneous catalytic reactions that hinder the long cycling catalysis,and it remains a big challenge to precisely control the active phase during the complex conditions in electrochemical catalysis.Here,we theoretically predict that carbon-based support could achieve the phase engineering regulation of catalysts by suppressing specific phase transformation.Taken single-walled carbon nanotube(SWCNT)as typical support,combined with calculated E-pH(Pourbaix)diagram and advanced synchrotron-based characterizations technologies prove there are two different active phases source from cobalt selenide which demonstrate that the feasibility of using support effect regulating the potential advantageous catalysts.Moreover,it is worth noting that the phase engineering derived Co_(3)O_(4)-SWCNT exhibits a low overpotential of 201 mV for delivering the current density of 10 mA/cm^(2)in electrocatalytic oxygen evolution reaction(OER).Also,it reaches a record current density of 529 mA/cm^(2)at 1.63 V(vs.RHE)in the electrocatalytic urea oxidation reaction(UOR),overwhelming most previously reported catalysts.展开更多
基金supported by the open fund of the National Defense Key Discipline Laboratory of New Micro/Nano Devices and System Technology,Zhejiang Provincial Natural Science Foundation of China,under Grant No.LY19E020014NSFC(Grant Nos 21303162 and 11604295)
文摘Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and supercapacitors.The 3D vertically orientated NiTe dendritic frameworks induce the homogeneous nucleation of 2D Ni_(x)Co_(12-x)Se nanosheet arrays along similar crystal directions and bring a strong interfacial binding between the integrated active components.In particular,the optimized Ni_(6)Co_(6)Se@NiTe with an interface coupling effect works in concert to tune the intrinsic activity.It only needs a low overpotential of 1.33 V to yield a current density of 10 mA cm^(-2)for alkaline urea electrolysis.Meanwhile,the full urea catalysis driven only by Ni_(6)Co_(6)Se@NiTe achieves 10 mA cm^(-2)at a potential of 1.38 V and can approach a constant level of the current response for 40 h.Besides,the integrated Ni_(6)Co_(6)Se@NiTe electrode delivers an enhanced specific capacity(223 mA h g^(-1)at 1 A g^(-1))with a high cycling stability.Consequently,a hybrid asymmetric supercapacitor(HASC)device based on Ni_(6)Co_(6)Se@NiTe exhibits a favorable rate capability and reaches a high energy density of 67.7 Wh kg^(-1)and a power density of 724.8 W kg^(-1)with an exceptional capacity retention of 92.4%after sequential 12000 cycles at 5 A g^(-1).
基金The authors extend their appreciation to the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)for funding and supporting this work through Research Partnership Program(No.RP-21-09-75).
文摘Deliberate modulation of the electronic structure via interface engineering is one of promising perspectives to build advanced catalysts for urea oxidation reaction(UOR)at high current densities.However,it still remains some challenges originating from the intrinsically sluggish UOR dynamics and the high energy barrier for urea adsorption.In response,we report the coupled NiSe_(2)nanowrinkles with Ni_(5)P_(4)nanorods heterogeneous structure onto Ni foam(denoted as NiSe_(2)@Ni_(5)P_(4)/NF)through successive phosphorization and selenization strategy,in which the produced closely contacted interface could provide high-flux electron transfer pathways.Theoretical findings decipher that the fast charge transfer takes place at the interfacial region from Ni_(5)P_(4)to NiSe_(2),which is conducive to optimizing adsorption energy of urea molecules.As expected,the well-designed NiSe_(2)@Ni_(5)P_(4)/NF only requires the low potential of 1.402 V at the current density of 500 mA·cm^(-2).More importantly,a small Tafel slope of 27.6 mV·dec^(-1),a high turnover frequency(TOF)value of 1.037 s^(-1)as well as the prolonged stability of 950 h at the current density of 100 mA·cm^(-2)are also achieved.This study enriches the understanding on the electronic structure modulation via interface engineering and offers bright prospect to design advanced UOR catalysts.
基金This work was supported by the Key Research and Development Program of Shandong Province(grant No.2019GGX103051)the Natural Science Foundation of Shandong Province(grant No.ZR2018JL009)the National Natural Science Foundation of China(grant No.21927811).
文摘The development of advanced electrocatalysts for electro-oxidation reactions has attracted much attention because of the critical role of such electrocatalysts in improving the overall efficiency of coupled hydrogen production.We have developed an efficient lanthanum-dopedα-Ni(OH)_(2) bifunctional catalyst with a 1D-2D-3D hierarchical nanostructure.It shows superior activity and stability in the anodic oxygen evolution reaction(OER)and urea oxidation reaction(UOR).Enrichment of the edge sites and conducting La doping inα-Ni(OH)_(2) phase enable formation and stabilization of abundant local Ni^(3+)ions.This guarantees ultralow onset potentials in electro-oxidation reactions.The 1D-2D-3D hierarchical nanostructure significantly boosts the in situ generation of high-valence active species,which results in efficient and stable OER and UOR performances,and the synergistic merit of doping-induced facile reaction kinetics.Because of the structural benefits of a large surface area,charge-transfer promotion,good structural stability,and bifunctionality,a 1%La-dopedα-Ni(OH)_(2) hierarchical nanostructure gives superior OER and UOR performances with low overpotentials,large catalytic current densities,and excellent operational stability.It is therefore a promising catalyst for use in simultaneous alkaline wastewater treatment and hydrogen production.
基金the National Key R&D Program of China(Nos.2020YFA0405800 and 2017YFA0303500)the National Natural Science Foundation of China(NSFC)(Nos.U1932201,U2032113,and 22075264)+3 种基金CAS Collaborative Innovation Program of Hefei Science Center(Nos.2019HSC-CIP002 and 2020HSC-CIP002)USTC Research Funds of the Double First-Class Initiative(No.YD2310002003)Institute of Energy,Hefei Comprehensive Nation Science Center,University Synergy Innovation Program of Anhui Province(GXXT-2020-002)CAS Iterdisciplinary Innovation Team.L.S.acknowledges the support from Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University(111 project,B12015)。
文摘The phase transformation of catalysts has been extensively observed in heterogeneous catalytic reactions that hinder the long cycling catalysis,and it remains a big challenge to precisely control the active phase during the complex conditions in electrochemical catalysis.Here,we theoretically predict that carbon-based support could achieve the phase engineering regulation of catalysts by suppressing specific phase transformation.Taken single-walled carbon nanotube(SWCNT)as typical support,combined with calculated E-pH(Pourbaix)diagram and advanced synchrotron-based characterizations technologies prove there are two different active phases source from cobalt selenide which demonstrate that the feasibility of using support effect regulating the potential advantageous catalysts.Moreover,it is worth noting that the phase engineering derived Co_(3)O_(4)-SWCNT exhibits a low overpotential of 201 mV for delivering the current density of 10 mA/cm^(2)in electrocatalytic oxygen evolution reaction(OER).Also,it reaches a record current density of 529 mA/cm^(2)at 1.63 V(vs.RHE)in the electrocatalytic urea oxidation reaction(UOR),overwhelming most previously reported catalysts.
