1 3
Topics in Current Chemistry (2020) 378:2
(shape and size) play a key role in the catalysis rates, and, as a result, the engineering of these features is also important [47, 69–80]. Toward the above-mentioned
direction, different strategies/approaches were followed for the nano-engineering of
the TiO 2 toward key features/properties for application in catalysis. The most important strategies in order to positively trigger the photoreactivity are the following:
(1) controlling the crystallographic nature; (2) introducing Ti
3+
species and lattice
disorder; (3) doping with metal or non-metal; (4) decreasing the size of the particles to nanoscale; (5) engineering the shape to 0D, 1D, 2D, 3D, or amorphous; (6)
decreasing the size of the particles; (7) chemical modification like hydroxylation/
hydrogenation; (8) porosity enhancement; (9) narrowing the bandgap toward the
visible range of light; (10) enhancing light absorption; and (11) limitation of e
−
/h
+
recombination.
1.6 Our Approach to Organize this Article
The focus of the work herein is based on novel mechanochemical-assisted synthesis/
modifications, such as US irradiation and ball milling, in which their utilization has
led to beneficial effects in the enhancement of photocatalytic capability. Since the
application of mechanochemistry has only lately been assumed and recognized as
a useful process-intensification tool, in most works where US or ball milling were
applied, the reports have predominately a materials point of view approach without studying a potential photocatalytic reaction. Additionally, the one-dimensionalinspired spatially ordered nanotubular-shaped titanate has gathered intense attention
upon its discovery in 1995 [81]. Although the utilization of mechanochemistry in
order to improve the synthesis and control specific features has been explored, the
photocatalytic capabilities of these titanate nanotubes (TiNTBs) was studied in only
a few of these reports. We believe that TiNTBs can display important photocatalyst
behavior, and we actively work towards this direction. Based on the above and the
available articles, we organized this article into two main parts/sections. In the first
part, we collected the reports in which sonication was used in order to obtain nanoengineered materials with enhanced specific features for photocatalytic application,
like light absorptivity, decreased bandgap, defects like surface oxygen vacancies,
hydroxylation, porosity, etc. The second part is focused on the ball milling-based
synthesis/modification approach. Each part is separated in two subsections. The first
subsection is focused on zero-dimensional (0-D) photocatalysts, with an emphasis
on how to promote the most vital of photochemistry features. In the second subsection, we collect all the research on the synthesis of one-dimensional (1-D) nanostructured titanate, like nanotubes (NTBs) and nanorods.
37
Reprinted from the journal
Topics in Current Chemistry (2020) 378:2
(shape and size) play a key role in the catalysis rates, and, as a result, the engineering of these features is also important [47, 69–80]. Toward the above-mentioned
direction, different strategies/approaches were followed for the nano-engineering of
the TiO 2 toward key features/properties for application in catalysis. The most important strategies in order to positively trigger the photoreactivity are the following:
(1) controlling the crystallographic nature; (2) introducing Ti
3+
species and lattice
disorder; (3) doping with metal or non-metal; (4) decreasing the size of the particles to nanoscale; (5) engineering the shape to 0D, 1D, 2D, 3D, or amorphous; (6)
decreasing the size of the particles; (7) chemical modification like hydroxylation/
hydrogenation; (8) porosity enhancement; (9) narrowing the bandgap toward the
visible range of light; (10) enhancing light absorption; and (11) limitation of e
−
/h
+
recombination.
1.6 Our Approach to Organize this Article
The focus of the work herein is based on novel mechanochemical-assisted synthesis/
modifications, such as US irradiation and ball milling, in which their utilization has
led to beneficial effects in the enhancement of photocatalytic capability. Since the
application of mechanochemistry has only lately been assumed and recognized as
a useful process-intensification tool, in most works where US or ball milling were
applied, the reports have predominately a materials point of view approach without studying a potential photocatalytic reaction. Additionally, the one-dimensionalinspired spatially ordered nanotubular-shaped titanate has gathered intense attention
upon its discovery in 1995 [81]. Although the utilization of mechanochemistry in
order to improve the synthesis and control specific features has been explored, the
photocatalytic capabilities of these titanate nanotubes (TiNTBs) was studied in only
a few of these reports. We believe that TiNTBs can display important photocatalyst
behavior, and we actively work towards this direction. Based on the above and the
available articles, we organized this article into two main parts/sections. In the first
part, we collected the reports in which sonication was used in order to obtain nanoengineered materials with enhanced specific features for photocatalytic application,
like light absorptivity, decreased bandgap, defects like surface oxygen vacancies,
hydroxylation, porosity, etc. The second part is focused on the ball milling-based
synthesis/modification approach. Each part is separated in two subsections. The first
subsection is focused on zero-dimensional (0-D) photocatalysts, with an emphasis
on how to promote the most vital of photochemistry features. In the second subsection, we collect all the research on the synthesis of one-dimensional (1-D) nanostructured titanate, like nanotubes (NTBs) and nanorods.
37
Reprinted from the journal