Electrochemical oxidation/reduction of radicals is a green and environmentally friendly approach to generating fuels.These reactions,however,suffer from sluggish kinetics due to a low local concentration of radicals a...Electrochemical oxidation/reduction of radicals is a green and environmentally friendly approach to generating fuels.These reactions,however,suffer from sluggish kinetics due to a low local concentration of radicals around the electrocatalyst.A large applied electrode potential can enhance the fuel generation efficiency via enhancing the radical concentration around the electrocatalyst sites,but this comes at the cost of electricity.Here,we report about a~45%saving in energy to achieve an electrochemical hydrogen generation rate of 3×10^(16) molecules cm^(–2)s^(–1)(current density:10 mA/cm^(2))through localized electric field-induced enhancement in the reagent concentration(LEFIRC)at laser-induced periodic surface structured(LIPSS)electrodes.The finite element model is used to simulate the spatial distribution of the electric field to understand the effects of LIPSS geometric parameters in field localization.When the LIPSS patterned electrodes are used as substrates to support Pt/C and RuO_(2) electrocatalysts,the η_(10) overpotentials for HER and OER are decreased by 40.4 and 25%,respectively.Moreover,the capability of the LIPSS-patterned electrodes to operate at significantly reduced energy is also demonstrated in a range of electrolytes,including alkaline,acidic,neutral,and seawater.Importantly,when two LIPSS patterned electrodes were assembled as the anode and cathode into a cell,it requires 330 mVs of lower electric potential with enhanced stability over a similar cell made of pristine electrodes to drive a current density of 10 mA/cm^(2).This work demonstrates a physical and versatile approach of electrode surface patterning to boost electrocatalytic fuel generation performance and can be applied to any metal and semiconductor catalysts for a range of electrochemical reactions.展开更多
Localized surface plasmon resonance(LSPR)of nanostructures and the interfacial charge transfer(CT)of semiconductor materials play essential roles in the study of optical and photoelectronic properties.In this paper,a ...Localized surface plasmon resonance(LSPR)of nanostructures and the interfacial charge transfer(CT)of semiconductor materials play essential roles in the study of optical and photoelectronic properties.In this paper,a composite substrate of Ag2S quantum dots(QDs)coated plasmonic Au bowtie nanoantenna(BNA)arrays with a metalinsulator-metal(MIM)configuration was built to study the synergistic effect of LSPR and interfacial CT using surface-enhanced Raman scattering(SERS)in the near-infrared(NIR)region.The Au BNA array structure with a large enhancement of the localized electric field(E-field)strongly enhanced the Raman signal of adsorbed p-aminothiophenol(PATP)probe molecules.Meanwhile,the broad enhanced spectral region was achieved owing to the coupling of LSPR The as-prepared Au BNA array structure facilitated enhancements of the excitation as well as the emission of Raman signal simultaneously,which was established by finite-difference time-domain simulation.Moreover,Ag2S semiconductor QDs were introduced into the BNA/PATP system to further enhance Raman signals,which benefited from the interfacial CT resonance in the BNA/Ag2S-QDs/PATP system.As a result,the Raman signals of PATP in the BNA/Ag2S-QDs/PATP system were strongly enhanced under 785 nm laser excitation due to the synergistic effect of E-field enhancement and interfacial CT.Furthermore,the SERS polarization dependence effeas of the BNA/Ag2S-QDs/PATP system were also investigated.The SERS spectra indicated that the polarization dependence of the substrate increased with decreasing polarization angles(θpola)of excitation from p-polarized(θpola=90°)excitation to s-polarized(θpola=0°)excitation.This study provides a strategy using the synergistic effect of interfacial CT and E-field enhancement for SERS applications and provides a guidance for the development of SERS study on semiconductor QD-based plasmonic substrates,and can be farther extended to other material-nanostructure systems for various optoelectronic and sensing applications.展开更多
基金National Natural Science Foundation of China (grant nos.62134009,62121005)the Innovation Grant of Changchun Institute of Optics,Fine Mechanics and Physics (CIOMP),Jilin Provincial Science and Technology Development Project (grant no:YDZJ202102CXJD002)Bill&Melinda Gates Foundation (grant no:OPP1157723)
文摘Electrochemical oxidation/reduction of radicals is a green and environmentally friendly approach to generating fuels.These reactions,however,suffer from sluggish kinetics due to a low local concentration of radicals around the electrocatalyst.A large applied electrode potential can enhance the fuel generation efficiency via enhancing the radical concentration around the electrocatalyst sites,but this comes at the cost of electricity.Here,we report about a~45%saving in energy to achieve an electrochemical hydrogen generation rate of 3×10^(16) molecules cm^(–2)s^(–1)(current density:10 mA/cm^(2))through localized electric field-induced enhancement in the reagent concentration(LEFIRC)at laser-induced periodic surface structured(LIPSS)electrodes.The finite element model is used to simulate the spatial distribution of the electric field to understand the effects of LIPSS geometric parameters in field localization.When the LIPSS patterned electrodes are used as substrates to support Pt/C and RuO_(2) electrocatalysts,the η_(10) overpotentials for HER and OER are decreased by 40.4 and 25%,respectively.Moreover,the capability of the LIPSS-patterned electrodes to operate at significantly reduced energy is also demonstrated in a range of electrolytes,including alkaline,acidic,neutral,and seawater.Importantly,when two LIPSS patterned electrodes were assembled as the anode and cathode into a cell,it requires 330 mVs of lower electric potential with enhanced stability over a similar cell made of pristine electrodes to drive a current density of 10 mA/cm^(2).This work demonstrates a physical and versatile approach of electrode surface patterning to boost electrocatalytic fuel generation performance and can be applied to any metal and semiconductor catalysts for a range of electrochemical reactions.
基金Chinese Academy of Sciences(QYZDB-SSWSYS038)National Natural Science Foundation of China(11674178,11774340,91750205,61705227)+1 种基金K.C.Wong Education Foundation(GJTD-2018-08)Jilin Provincial Science&Technology Development Project(20180414019GH)。
文摘Localized surface plasmon resonance(LSPR)of nanostructures and the interfacial charge transfer(CT)of semiconductor materials play essential roles in the study of optical and photoelectronic properties.In this paper,a composite substrate of Ag2S quantum dots(QDs)coated plasmonic Au bowtie nanoantenna(BNA)arrays with a metalinsulator-metal(MIM)configuration was built to study the synergistic effect of LSPR and interfacial CT using surface-enhanced Raman scattering(SERS)in the near-infrared(NIR)region.The Au BNA array structure with a large enhancement of the localized electric field(E-field)strongly enhanced the Raman signal of adsorbed p-aminothiophenol(PATP)probe molecules.Meanwhile,the broad enhanced spectral region was achieved owing to the coupling of LSPR The as-prepared Au BNA array structure facilitated enhancements of the excitation as well as the emission of Raman signal simultaneously,which was established by finite-difference time-domain simulation.Moreover,Ag2S semiconductor QDs were introduced into the BNA/PATP system to further enhance Raman signals,which benefited from the interfacial CT resonance in the BNA/Ag2S-QDs/PATP system.As a result,the Raman signals of PATP in the BNA/Ag2S-QDs/PATP system were strongly enhanced under 785 nm laser excitation due to the synergistic effect of E-field enhancement and interfacial CT.Furthermore,the SERS polarization dependence effeas of the BNA/Ag2S-QDs/PATP system were also investigated.The SERS spectra indicated that the polarization dependence of the substrate increased with decreasing polarization angles(θpola)of excitation from p-polarized(θpola=90°)excitation to s-polarized(θpola=0°)excitation.This study provides a strategy using the synergistic effect of interfacial CT and E-field enhancement for SERS applications and provides a guidance for the development of SERS study on semiconductor QD-based plasmonic substrates,and can be farther extended to other material-nanostructure systems for various optoelectronic and sensing applications.
