interestingly, we found that the addition of glucose during the hydrothermal treatment could achieve the in situ growth of TiO 2 nanocrystals with (001) facets on the
surface of aerogel, which results in the highly dispersed TiO 2 nanocrystals on the
graphene due to the strong interaction between TiO 2 and graphene. As described in
our report (Fig. 5.11), Ti(SO 4 ) 2 was used as the titanium source to be first dissolved
in an aqueous solution. The cultivation of TiO 2 crystal seeds was necessary before a
known amount of glucose being adsorbed on the seeds. During the hydrothermal
process, large numbers of glucose molecules are adsorbed onto the TiO 2 (001)
facets, generating nanosized seeds with exposed (001) facets owing to many
hydroxyl groups on glucose. The hydroxyl groups at one end of glucose are
connected with GR, while the hydroxyl groups at the other end are connected with
the TiO 2 facets. Thus, the hydroxyl groups enabled glucose to serve as the linker
achieving the in situ growth of TiO 2 nanocrystals on a GA surface.
Evaporation-induced self-assembly technology is another method involving low
energy consumption and operability, which has widely been used in the preparation
of 3D-structured TiO 2 /graphene composites. Hou et al. [67] reported a roomtemperature synthesis of chemically bonded TiO 2 –graphene composite hydrogels
and applied them in the visible light-driven photocatalysis. Graphene oxide, P25,
and other precursors were mixed together at room temperature, and then the mixture
Fig. 5.11 (a) Glucose-linked transformation pathway for the in situ growth of TiO 2 nanocrystals
with (001) facets on the GA surface. (b) TEM image for TiO 2 /GAs (67 wt% of TiO 2 in TiO 2 /GAs).
Inset (b) is the corresponding morphology distribution of the TiO 2 nanocrystals derived from 100 of
TiO 2 crystals in image (b). (c) HRTEM image for TiO 2 /GAs (67 wt%). Inset (c) is the
corresponding fast Fourier transform (FFT) pattern. (Reprinted with permission from Ref.
[66]. Copyright 2014, American Chemical Society)
5.2 TiO 2 /Graphene Composite
119
surface of aerogel, which results in the highly dispersed TiO 2 nanocrystals on the
graphene due to the strong interaction between TiO 2 and graphene. As described in
our report (Fig. 5.11), Ti(SO 4 ) 2 was used as the titanium source to be first dissolved
in an aqueous solution. The cultivation of TiO 2 crystal seeds was necessary before a
known amount of glucose being adsorbed on the seeds. During the hydrothermal
process, large numbers of glucose molecules are adsorbed onto the TiO 2 (001)
facets, generating nanosized seeds with exposed (001) facets owing to many
hydroxyl groups on glucose. The hydroxyl groups at one end of glucose are
connected with GR, while the hydroxyl groups at the other end are connected with
the TiO 2 facets. Thus, the hydroxyl groups enabled glucose to serve as the linker
achieving the in situ growth of TiO 2 nanocrystals on a GA surface.
Evaporation-induced self-assembly technology is another method involving low
energy consumption and operability, which has widely been used in the preparation
of 3D-structured TiO 2 /graphene composites. Hou et al. [67] reported a roomtemperature synthesis of chemically bonded TiO 2 –graphene composite hydrogels
and applied them in the visible light-driven photocatalysis. Graphene oxide, P25,
and other precursors were mixed together at room temperature, and then the mixture
Fig. 5.11 (a) Glucose-linked transformation pathway for the in situ growth of TiO 2 nanocrystals
with (001) facets on the GA surface. (b) TEM image for TiO 2 /GAs (67 wt% of TiO 2 in TiO 2 /GAs).
Inset (b) is the corresponding morphology distribution of the TiO 2 nanocrystals derived from 100 of
TiO 2 crystals in image (b). (c) HRTEM image for TiO 2 /GAs (67 wt%). Inset (c) is the
corresponding fast Fourier transform (FFT) pattern. (Reprinted with permission from Ref.
[66]. Copyright 2014, American Chemical Society)
5.2 TiO 2 /Graphene Composite
119