The vertically aligned one-dimensional(1 D)core-shell structure can maximize the exposure and use of the functionally active surface while maintaining the geometric effects caused by the underlying structure.Herein,we...The vertically aligned one-dimensional(1 D)core-shell structure can maximize the exposure and use of the functionally active surface while maintaining the geometric effects caused by the underlying structure.Herein,we have fabricated 1 D vertically aligned ZnO/V2O5 core-shell hetero-nanostructure nanorod arrays(NRs)for photoelectrochemical(PEC)water splitting.ZnO/V2O5 NRs were prepared through the hydrothermal growing of ZnO NRs and then radio frequency(RF)magnetron sputtering deposition of V2O5 for 300,600 and 900 s.The photocurrent density of ZnO/V2O5-based photoanodes was gradually increased with the sputtering time,reaching the maximum value of 1.21 m A/cm^2 at 1.23 V vs.reversible hydrogen electrode(RHE)for ZnO/V2O5-600,whereas for pure ZnO-based photoanode was 0.42 mA/cm^2.The incident photon to electron conversion efficiency(IPCE)of ZnO/V2O5-600 evaluated to be 82.3%which was 2.3 times higher than that of ZnO(36.4%).The improved PEC performance of ZnO/V2O5-600 is because the core-shell structure with a moderate thickness of the V2O5 layer has the extremely high carrier density,largest electrochemically active surface area(ECSA),largest carrier density,lowest charge recombination rate,and the longest lifetime of e-h pairs due to the formation of the staggered gap junction.This study provides an effective way to design and fabrication of hetero-nanostructures for highefficiency photoelectrodes.展开更多
Rechargeable aqueous zinc ion hybrid capacitors(ZIHCs),as an up-and-comer aqueous electrochemical energy storage system,endure in their infancy because of the substandard reversibility of Zn anodes,structural deterior...Rechargeable aqueous zinc ion hybrid capacitors(ZIHCs),as an up-and-comer aqueous electrochemical energy storage system,endure in their infancy because of the substandard reversibility of Zn anodes,structural deterioration of cathode materials,and narrow electrochemical stability window.Herein,a scalable approach is described that addresses Zn-anode/electrolyte interface and cathode materials associated deficiencies and boosts the electrochemical properties of ZIHCs.The Zn-anode/electrolyte interface is self-regulated by alteration of the traditional Zn2+electrolyte with Na-based supporting salt without surrendering the cost,safety,and green features of the Zn-based system which further validates the excellent reversibility over 1100 h with suppressed hydrogen evolution.The deficits of cathode materials were overcome by using a high-mass loaded,oxygen-rich,3D,multiscaled graphene-like carbon(3D MGC)cathode.Due to the multiscaled texture,high electronic conductivity,and oxygen-rich functional groups of 3D MGC,reversible redox capacitance was obtained with a traditional adsorption/desorption mechanism.Prototype ZIHCs containing the modified electrolyte and an oxygen-rich 3D MGC cathode resulted in battery-like specific energy(203 Wh kg1 at 1.6 A g^(-1))and supercapacitor-type power capability(4.9 kW kg1 at 8 A g^(-1))with outstanding cycling durability(96.75%retention over 30000 cycles at 10 A g^(-1)).These findings pave the way toward the utilization of highly efficient ZIHCs for practical applications.展开更多
基金supported by National Research Foundation(NRF)of Korean grant funded by the Korea government(MSIP)(Grant number:2017R1E1A1A01074550)。
文摘The vertically aligned one-dimensional(1 D)core-shell structure can maximize the exposure and use of the functionally active surface while maintaining the geometric effects caused by the underlying structure.Herein,we have fabricated 1 D vertically aligned ZnO/V2O5 core-shell hetero-nanostructure nanorod arrays(NRs)for photoelectrochemical(PEC)water splitting.ZnO/V2O5 NRs were prepared through the hydrothermal growing of ZnO NRs and then radio frequency(RF)magnetron sputtering deposition of V2O5 for 300,600 and 900 s.The photocurrent density of ZnO/V2O5-based photoanodes was gradually increased with the sputtering time,reaching the maximum value of 1.21 m A/cm^2 at 1.23 V vs.reversible hydrogen electrode(RHE)for ZnO/V2O5-600,whereas for pure ZnO-based photoanode was 0.42 mA/cm^2.The incident photon to electron conversion efficiency(IPCE)of ZnO/V2O5-600 evaluated to be 82.3%which was 2.3 times higher than that of ZnO(36.4%).The improved PEC performance of ZnO/V2O5-600 is because the core-shell structure with a moderate thickness of the V2O5 layer has the extremely high carrier density,largest electrochemically active surface area(ECSA),largest carrier density,lowest charge recombination rate,and the longest lifetime of e-h pairs due to the formation of the staggered gap junction.This study provides an effective way to design and fabrication of hetero-nanostructures for highefficiency photoelectrodes.
基金the National Research Foundation of South Korea(NRF)grant funded by the Korea government(MSIT)(2020R1A4A3079710and 2022M3J7A106294).DeepakP.Dubal acknowledges QUT's start-upgrant—323000-0424/07and financial support from Centre for Materials Science and Centre for Waste Free World,QUT,Australia.
文摘Rechargeable aqueous zinc ion hybrid capacitors(ZIHCs),as an up-and-comer aqueous electrochemical energy storage system,endure in their infancy because of the substandard reversibility of Zn anodes,structural deterioration of cathode materials,and narrow electrochemical stability window.Herein,a scalable approach is described that addresses Zn-anode/electrolyte interface and cathode materials associated deficiencies and boosts the electrochemical properties of ZIHCs.The Zn-anode/electrolyte interface is self-regulated by alteration of the traditional Zn2+electrolyte with Na-based supporting salt without surrendering the cost,safety,and green features of the Zn-based system which further validates the excellent reversibility over 1100 h with suppressed hydrogen evolution.The deficits of cathode materials were overcome by using a high-mass loaded,oxygen-rich,3D,multiscaled graphene-like carbon(3D MGC)cathode.Due to the multiscaled texture,high electronic conductivity,and oxygen-rich functional groups of 3D MGC,reversible redox capacitance was obtained with a traditional adsorption/desorption mechanism.Prototype ZIHCs containing the modified electrolyte and an oxygen-rich 3D MGC cathode resulted in battery-like specific energy(203 Wh kg1 at 1.6 A g^(-1))and supercapacitor-type power capability(4.9 kW kg1 at 8 A g^(-1))with outstanding cycling durability(96.75%retention over 30000 cycles at 10 A g^(-1)).These findings pave the way toward the utilization of highly efficient ZIHCs for practical applications.
