Plasmon-enhanced electrocatalysis(PEEC)is an emerging approach to mitigate CO_(2)emissions.The mechanisms behind CO_(2)adsorption and reduction at the catalyst-electrolyte interface in PEEC still need to be further ex...Plasmon-enhanced electrocatalysis(PEEC)is an emerging approach to mitigate CO_(2)emissions.The mechanisms behind CO_(2)adsorption and reduction at the catalyst-electrolyte interface in PEEC still need to be further explored.Herein,we employ a well-defined Ag nanostructure to elucidate these pivotal issues.By shining light with wavelengths of 625,525,405 nm on Ag,an adjustable CO/H_(2)ratio from 35 to 1 can be obtained.The reaction pathway changing under plasmonic excitation does not originate from the lowered CO_(2)mass transfer in the vicinity of Ag,as the electrochemical quartz crystal microbalance results unravel that a slightly elevated temperature in bulk electrolyte caused by light irradiation cannot weaken the CO_(2)adsorption at the Ag catalyst-electrolyte interface.Theoretical calculations reveal that optical excitation towards shorter wavelengths leads to a progressive lowered energy barrier for H_(2)formation together with an enhanced energy barrier for^(*)COOH formation.Although thermodynamically suppressed,CO_(2)reduction can still be improved kinetically by optimizing the excitation wavelength and intensity,being accompanied with the enhanced photocurrent.Transient absorption spectroscopy results further correlate the higher photocurrent with a prolonged electron-phonon coupling time,verifying that the improvement of CO_(2)reduction kinetics in PEEC can be realized by hot electron harnessing.展开更多
基金support from Alexander von Humboldt foundationthe National Natural Science Foundation of China(Nos.21972006,U2001217 and 22261160370)+1 种基金the funding from Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under grant numbers EXC 2089/1-390776260(Germany’s Excellence Strategy)and TI 1063/1(Emmy Noether Program),the Bavarian Program Solar Energies Go Hybrid(SolTech)and the Center for NanoScience(CeNS).Co-funded by the European Union(ERC,METANEXT,101078018)expressed are however those of the author(s)only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency.Neither the European Union nor the granting authority can be held responsible for them.
文摘Plasmon-enhanced electrocatalysis(PEEC)is an emerging approach to mitigate CO_(2)emissions.The mechanisms behind CO_(2)adsorption and reduction at the catalyst-electrolyte interface in PEEC still need to be further explored.Herein,we employ a well-defined Ag nanostructure to elucidate these pivotal issues.By shining light with wavelengths of 625,525,405 nm on Ag,an adjustable CO/H_(2)ratio from 35 to 1 can be obtained.The reaction pathway changing under plasmonic excitation does not originate from the lowered CO_(2)mass transfer in the vicinity of Ag,as the electrochemical quartz crystal microbalance results unravel that a slightly elevated temperature in bulk electrolyte caused by light irradiation cannot weaken the CO_(2)adsorption at the Ag catalyst-electrolyte interface.Theoretical calculations reveal that optical excitation towards shorter wavelengths leads to a progressive lowered energy barrier for H_(2)formation together with an enhanced energy barrier for^(*)COOH formation.Although thermodynamically suppressed,CO_(2)reduction can still be improved kinetically by optimizing the excitation wavelength and intensity,being accompanied with the enhanced photocurrent.Transient absorption spectroscopy results further correlate the higher photocurrent with a prolonged electron-phonon coupling time,verifying that the improvement of CO_(2)reduction kinetics in PEEC can be realized by hot electron harnessing.
