TY - JOUR
T1 - Unraveling the Hydrogenation of TiO2 and Graphene Oxide/TiO2 Composites in Real Time by in Situ Synchrotron X-ray Powder Diffraction and Pair Distribution Function Analysis
AU - Nguyen-Phan, Thuy Duong
AU - Liu, Zongyuan
AU - Luo, Si
AU - Gamalski, Andrew D.
AU - Vovchok, Dimitry
AU - Xu, Wenqian
AU - Stach, Eric A.
AU - Polyansky, Dmitry E.
AU - Fujita, Etsuko
AU - Rodriguez, José A.
AU - Senanayake, Sanjaya D.
PY - 2016/2/18
Y1 - 2016/2/18
N2 - The functionalization of graphene oxide (GO) and graphene by TiO2 and other metal oxides has attracted considerable attention due to numerous promising applications in catalysis, energy conversion, and storage. Hydrogenation of this class of materials has been proposed as a promising way to tune catalytic properties by altering the structural and chemical transformations that occur upon H incorporation. Herein, we investigate the structural changes that occur during the hydrogenation process using in situ powder X-ray diffraction and pair distribution function analysis of GO-TiO2 and TiO2 under H2 reduction. Sequential Rietveld refinement was employed to gain insight into the evolution of crystal growth of TiO2 nanoparticles in the presence of two-dimensional (2D) GO nanosheets. GO sheets not only significantly retarded the nucleation and growth of rutile impurities, stabilizing the anatase structure, but was also partially reduced to hydrogenated graphene by the introduction of atomic hydrogen into the honeycomb lattice. We discuss the hydrogenation processes and the resulting composite structure that occurs during the incorporation of atomic H and the dynamic structural transformations that leads to a highly active photocatalyst.
AB - The functionalization of graphene oxide (GO) and graphene by TiO2 and other metal oxides has attracted considerable attention due to numerous promising applications in catalysis, energy conversion, and storage. Hydrogenation of this class of materials has been proposed as a promising way to tune catalytic properties by altering the structural and chemical transformations that occur upon H incorporation. Herein, we investigate the structural changes that occur during the hydrogenation process using in situ powder X-ray diffraction and pair distribution function analysis of GO-TiO2 and TiO2 under H2 reduction. Sequential Rietveld refinement was employed to gain insight into the evolution of crystal growth of TiO2 nanoparticles in the presence of two-dimensional (2D) GO nanosheets. GO sheets not only significantly retarded the nucleation and growth of rutile impurities, stabilizing the anatase structure, but was also partially reduced to hydrogenated graphene by the introduction of atomic hydrogen into the honeycomb lattice. We discuss the hydrogenation processes and the resulting composite structure that occurs during the incorporation of atomic H and the dynamic structural transformations that leads to a highly active photocatalyst.
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U2 - 10.1021/acs.jpcc.5b09504
DO - 10.1021/acs.jpcc.5b09504
M3 - Article
AN - SCOPUS:84959017615
VL - 120
SP - 3472
EP - 3482
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 6
ER -