In Situ Raman Probing of Hot‐Electron Transfer at Gold–Graphene Interfaces with Atomic Layer Accuracy

Abstract

Plasmonic metals under photoexcitation can generate energetic hot electrons to directly induce chemical reactions.H owever,t he capability and fundamental insights of the transportation of these hot electrons at plasmonic metal-2D material interfaces remain unclear.H erein, hot-electron transfer at Au-graphene interfaces has been in situ studied using surface-enhanced Raman spectroscopy( SERS) with atomic layer accuracy.C ombining in situ SERS studies with density functional theory calculations,i ti sp roved that hot electrons can be injected from plasmonic Au nanoparticles to graphene and directly penetrate graphene to trigger photocatalytic reactions.W ith increasing graphene layers,t he transportation of hot electrons decays rapidly and would be completely blocked after five layers of graphene.M oreover, the transfer of hot electrons can be modulated by applying an external electric field, and the hot-electron transfer efficiency under electrochemical conditions is improved by over three times in the presence of amonolayer of graphene.

Graphene-Isolated Satellite Nanostructure Enhanced Raman Spectroscopy Reveals the Critical Role of Different Intermediates on the Oxygen Reduction Reaction

“…Such a nanoalloying effect has been attributed to the well-known strain or electronic effect according to various experimental and theoretical studies. − Meanwhile, tuning the metal–support interactions by using different catalyst supports can also promote the ORR kinetics. Among them, graphene (G) has attracted particular attention, due to its excellent conductivity, high surface area, strong adhesion to catalyst particles, and good chemical and environmental stability. , For example, assembly of PtFe nanoparticles (NPs) on the G show excellent catalytic performances via the construction of active G-PtFe interfaces, − which significantly improve the activity and stability of the ORR on PtFe . However, the exact role of the graphene-PtFe interactions on the ORR, especially how it regulates the interactions between the alloy catalysts and surface species/intermediates during the ORR, is obscure, due to the lack of direct experimental evidence.…”

Enhanced plasmonic photocatalytic performance of C3N4/Cu by the introduction of a reduced graphene oxide interlayer

“…Orbital wave functions before and after excitation are mainly distributed in Cu and RGO, respectively, indicating that hot electrons are transferred from Cu to RGO after light excitation. 83 The work function of the Cu (111) face (Fig. S8c, ESI †) was determined to be 4.56 eV by DFT, which is smaller than that of the (002) face of RGO (Fig.…”

Direct S–H Evidence Revealing the Photo-electrocatalytic Hydrogen Evolution Reaction Mechanism on CdS Using Surface-Enhanced Raman Spectroscopy

“…Current conventional spectroscopic techniques are inadequate for capturing trace adsorbate species due to their low concentration, complex interfacial environment, short lifetime, and dynamic characteristic during reaction. Surface-enhanced Raman spectroscopy (SERS) has demonstrated its potential in recent years for capturing reaction intermediate species and revealing reaction mechanisms. − Not only does it provide chemical bond-specific signals but it also amplifies the surface Raman signals by millions of times. , The “borrowing” SERS strategy allows for in situ monitoring of chemical reactions on various non-SERS active materials. For example, structured Au@PtNi core–shell nanoparticles (NPs) can optimize the surface binding of *OOH on Pt and improve ORR performance through Ni-doping, as demonstrated in studies investigating the ORR process …”