Electron Hopping Through Single-to-Few-Layer Graphene Oxide Films. Side-Selective Photocatalytic Deposition of Metal Nanoparticles

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• 作者：Ian V. Lightcap ; Sean Murphy ; Timothy Schumer ; Prashant V. Kamat
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：June 7, 2012
• 年：2012
• 卷：3
• 期：11
• 页码：1453-1458
• 全文大小：427K
• 年卷期：v.3,no.11(June 7, 2012)
• ISSN：1948-7185

文摘

Single- to few-layer graphene oxide (GO) sheets have been successfully anchored onto TiO₂ films using electrophoretic deposition. Upon UV illumination of TiO₂鈥揋O films, photogenerated electrons from TiO₂ are captured by GO. These electrons are initially used in GO鈥檚 reduction, while additional electron transfer results in storage across its sp² network. In the presence of silver ions, deposition of silver nanoparticles (NPs) is accomplished on the GO surface opposite the TiO₂, thus confirming the ability of GO to transport electrons through its plane. Illumination-controlled reduction of silver ions allows for simple selection of particle size and loading, making these semiconductor鈥揼raphene鈥搈etal (SGM) films ideal for custom catalysis and sensor applications. Initial testing of SGM films as surface-enhanced resonance Raman (SERRS) sensors produced significant target molecule signal enhancements, enabling detection of nanomolar concentrations.

Keywords:

graphene; surface-enhanced Raman; SERS; SERRS; sensor; catalysis; catalyst; titanium dioxide; graphene oxide; reduced graphene oxide; electrophoretic deposition; EPD; semiconductor; metal; nanoparticles; surface plasmon resonance