It is of significance to design of stable and cost-effective electrocatalyst for water splitting with high efficiency in an alkaline medium.The major obstacles for practical application of water splitting devices are ...It is of significance to design of stable and cost-effective electrocatalyst for water splitting with high efficiency in an alkaline medium.The major obstacles for practical application of water splitting devices are lack of high-efficiency and low-cost electrocatalysts with low overpotential for both HER and OER.In this paper,we report a NiFe alloy decorated NiCoO2 hollow polyhedron(denoted as Ni Fe–Ni Co O2)by using[NiFe(CN)6]- intercalated NiCo–LDH as precursor.As evidenced by the electrochemical active surface area,the resultant Ni Fe–Ni Co O2 composite shows unique hollow nanostructure,which can not only provide abundant mass transport channels,but also increase the contact area of the NiFe–Ni Co O2 material with the electrolyte.The overpotential(η)demand is 286 mV for OER and 102 mV for HER at the current density of 10 mA/cm2 in an alkaline medium of 1 M KOH for the NiFe/NiCoO2 composite.This work provides a new pathway for preparation of the highly efficient bifunctional electrocatalysts for water splitting.展开更多
In power storage technology,ion exchange is widely used to modify the electronic structures of electrode materials to stimulate their electrochemical properties.Here,we proposed a multistep ion exchange(cation exchang...In power storage technology,ion exchange is widely used to modify the electronic structures of electrode materials to stimulate their electrochemical properties.Here,we proposed a multistep ion exchange(cation exchange and anion exchange) strategy to synthesize amorphous Ni-Co-S and β-Co(OH)_(2) hybrid nanomaterials with a hollow polyhedron structures.The synergistic effects of different components and the remarkable superiorities of hollow structure endow Ni-Co-S/Co(OH)_(2) electrode with outstanding electrochemical performance,including ultra-high specific capacity(1440.0 C/g at 1 A/g),superior capacitance retention rate(79.1% retention at 20 A/g) and long operating lifespan(81.4% retention after5000 cycles).Moreover,the corresponding hybrid supercapacitor enjoys a high energy density of 58.4 Wh/kg at the power density of 0.8 kW/kg,and a decent cyclability that the capacitances are maintained at80.8% compared with the initial capacitance.This research presents a high-performance electrode material and provides a promising route for the construction of electrode materials for supercapacitors with both structural and component advantages.展开更多
基金supported by the National Nature Science Foundation of China (U1707603, 21625101, 21521005, U1507102)the National Key Research and Development Program of China (2017YFB0307303)+2 种基金the 973 program (Grant No. 2014CB932104)Beijing Natural Science Foundation (2182047)the Fundamental Research Funds for the Central Universities (ZY1709)
文摘It is of significance to design of stable and cost-effective electrocatalyst for water splitting with high efficiency in an alkaline medium.The major obstacles for practical application of water splitting devices are lack of high-efficiency and low-cost electrocatalysts with low overpotential for both HER and OER.In this paper,we report a NiFe alloy decorated NiCoO2 hollow polyhedron(denoted as Ni Fe–Ni Co O2)by using[NiFe(CN)6]- intercalated NiCo–LDH as precursor.As evidenced by the electrochemical active surface area,the resultant Ni Fe–Ni Co O2 composite shows unique hollow nanostructure,which can not only provide abundant mass transport channels,but also increase the contact area of the NiFe–Ni Co O2 material with the electrolyte.The overpotential(η)demand is 286 mV for OER and 102 mV for HER at the current density of 10 mA/cm2 in an alkaline medium of 1 M KOH for the NiFe/NiCoO2 composite.This work provides a new pathway for preparation of the highly efficient bifunctional electrocatalysts for water splitting.
基金supported by the National Natural Science Foundation of China (Nos.51802177,51672109)the Independent Cultivation Program of Innovation Team of Ji’nan City (No.2019GXRC011)。
文摘In power storage technology,ion exchange is widely used to modify the electronic structures of electrode materials to stimulate their electrochemical properties.Here,we proposed a multistep ion exchange(cation exchange and anion exchange) strategy to synthesize amorphous Ni-Co-S and β-Co(OH)_(2) hybrid nanomaterials with a hollow polyhedron structures.The synergistic effects of different components and the remarkable superiorities of hollow structure endow Ni-Co-S/Co(OH)_(2) electrode with outstanding electrochemical performance,including ultra-high specific capacity(1440.0 C/g at 1 A/g),superior capacitance retention rate(79.1% retention at 20 A/g) and long operating lifespan(81.4% retention after5000 cycles).Moreover,the corresponding hybrid supercapacitor enjoys a high energy density of 58.4 Wh/kg at the power density of 0.8 kW/kg,and a decent cyclability that the capacitances are maintained at80.8% compared with the initial capacitance.This research presents a high-performance electrode material and provides a promising route for the construction of electrode materials for supercapacitors with both structural and component advantages.
