Plasmon-enhanced photocurrent generation from click-chemically modified graphene

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Visible-light responsive materials are crucial for energy applications.
• Graphene-based nanocomposites offer unique electronic properties.
• Molecular bridges influence charge transfer in nanomaterials.

Purpose of the Study:

• To investigate the effect of different molecular bridges on the visible-light response of gold nanoparticles (AuNPs) assembled on reduced graphene oxide (rGO).
• To compare the performance of triazole-based linkers with traditional aminopropyltrimethoxysilane (APTMS) linkers.
• To understand the mechanism of enhanced electron transfer facilitated by specific molecular architectures.

Main Methods:

• Fabrication of reduced graphene oxide (rGO) functionalized with two types of self-assembled monolayers (SAMs): linear APTMS and aromatic triazoles via click chemistry.
• Transient photocurrent generation measurements to assess visible-light response.
• Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to evaluate electron transfer kinetics and surface resistance.

Main Results:

• A fivefold enhancement in photocurrent was observed for AuNPs/rGO systems utilizing triazole linkers compared to those with APTMS linkers.
• Electrochemical measurements indicated significantly lower charge transfer resistance for the triazole-modified rGO surface.
• The triazole linker effectively facilitated efficient electron transfer between the donor AuNPs and the acceptor rGO.

Conclusions:

• Aromatic triazole linkers, synthesized through click chemistry, significantly improve the visible-light performance of AuNP/rGO nanocomposites.
• The enhanced performance is attributed to the efficient electron bridging provided by the triazole moiety, reducing interfacial resistance.
• This study highlights the potential of tailored molecular engineering for optimizing charge dynamics in nanomaterial-based devices.