Journal
JOURNAL OF PHYSICAL CHEMISTRY C
Volume 116, Issue 1, Pages 1535-1543Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp209035e
Keywords
-
Funding
- KOSEF NRL program
- Korea government (MEST) [R0A-2008-000-20068-0]
- KOSEF EPB center [R11-2008-052-02002]
- Korea Center for Artificial Photosynthesis (KCAP: Sogang Univ.)
- MEST through NRF [2009-C1AAA001-2009-0093879]
- National Research Foundation of Korea [2008-0062041, 2008-0060152] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
Ask authors/readers for more resources
Size controlled nanographene oxides (NGOs; <50 nm) were prepared by a two-step oxidation process and NGOs were self-assembled with TiO2 nanoparticles to form the core/shell structure. Nanosized GO coated TiO2 nanoparticles (NGOTs) were then reduced by a photocatalytic process under UV irradiation to obtain graphene-coated TiO2. This is dearly different from the typical graphene/TiO2 composite with the particles-on-a-sheet geometry and is the first study on the core/shell structure of its kind. The physicochemical properties of NGOs and the reduced NGOTs (r-NGOTs) were characterized by various analytical and spectroscopic methods (AFM, FT-M, XPS, TEM, EELS, etc.). The photocatalytic and photoelectrochemical activities of r-NGOT were compared with a composite of r-GO/TiO2 that has TiO2 nanoparticles loaded on a larger graphene sheet (r-LGOT). The photocatalytic production of hydrogen was measured in the aqueous suspension of the composite photocatalyst under UV irradiation (lambda > 320 nm), and the photoelectrochemical behaviors were characterized using the electrode coated with the composite photocatalyst. The rates of H-2 production and photocurrent generation were higher with r-NGOT than r-LGOT, which indicates that the presence of r-GO shell on the surface of TiO2 facilitates the interfacial electron transfer. The direct contact between r-NGO and TiO2 is maximized in r-NGOT by retarding the charge recombination and accelerating the electron transfer. The geometry of the core/shell structure should be effective in the design of a graphene/TiO2 composite for solar conversion applications.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available