398
11 Templated Systems
respectively. Examples include the deposition of MnO 2 from MnSO 4 precursor material [302], TiO 2 from TiCl 3 [303] and V 2 O 5 from VOSO 4 [304], all from aqueous
solutions. Concerning the improvement of properties due to the macroporous nature,
MnO 2 was shown to exhibit better supercapacitance than flat films. Although very
little is known about the impact of the deposition conditions on the resulting macroporous anodic oxides, the study of the deposition of V 2 O 5 revealed that both the
substrate and the deposition potential can be optimized for the desired target property
[304].
Electrodeposition of semiconductors. 3DOM Si [305] and Si–Ge with varying
composition [306] can be electroplated into colloidal templates from ionic liquids
by using SiCl 4 and GeCl 4 as precursor materials. The treatment of all components
of the bath requires glove box environment to keep oxygen and water vapour away,
and as-prepared samples of high surface have to be cleaned thoroughly in order to
avoid oxidation. A slight Ge excess was found in Si–Ge samples as compared to the
component ratio in the bath.
II-VI type semiconductors, CdSe [237, 307–309] and CdS [237], were also synthesized as 3DOM materials. Both CdSe and CdS can be synthesized from aqueous solution with some excess of Cd
2+ as compared to the calcogenic precursor compounds
(SeO 2 and Na 2 S 2 O 3 ), while CdS can also be obtained from organic solutions in
which elemental sulphur is the source of the chalcogenide component. Semiconductor 3DOM structures are all peculiar for photonic properties, especially due to
their light absorption in the infrared range.
Polymer deposition into colloidal templates. Colloidal templates make it possible
to deposit polymer films with a great variety. Apart from the various polymer
compositions (such as polypyrrole [310], poly(para-phenylene) [311] and poly(3,4ethylenedioxythiophene) [312], etc.), the different filling ratios applied allow a
morphological variety. Interestingly, polymers electrodeposited into multilayered
colloidal templates can be obtained in self-supporting form after the removal of the
templating particles, in spite of the softness of the polymer materials as compared to
metals.
11.3.4 The Double-Templating Method Based
on Nanosphere Lithography
In the methods discussed in the present chapter, the primary template is made from
colloidal particles. This template is filled up with a suitable material that makes an
inverse opal structure. Then, the primary template is removed, and the resulting empty
inverse opal structure is used as a secondary template. These procedures vary in which
step applies electrochemical deposition (the first, the second or both). The scheme
of the double-templating process and a few images of the resulting nanostructures
are presented in Fig. 11.17.
11 Templated Systems
respectively. Examples include the deposition of MnO 2 from MnSO 4 precursor material [302], TiO 2 from TiCl 3 [303] and V 2 O 5 from VOSO 4 [304], all from aqueous
solutions. Concerning the improvement of properties due to the macroporous nature,
MnO 2 was shown to exhibit better supercapacitance than flat films. Although very
little is known about the impact of the deposition conditions on the resulting macroporous anodic oxides, the study of the deposition of V 2 O 5 revealed that both the
substrate and the deposition potential can be optimized for the desired target property
[304].
Electrodeposition of semiconductors. 3DOM Si [305] and Si–Ge with varying
composition [306] can be electroplated into colloidal templates from ionic liquids
by using SiCl 4 and GeCl 4 as precursor materials. The treatment of all components
of the bath requires glove box environment to keep oxygen and water vapour away,
and as-prepared samples of high surface have to be cleaned thoroughly in order to
avoid oxidation. A slight Ge excess was found in Si–Ge samples as compared to the
component ratio in the bath.
II-VI type semiconductors, CdSe [237, 307–309] and CdS [237], were also synthesized as 3DOM materials. Both CdSe and CdS can be synthesized from aqueous solution with some excess of Cd
2+ as compared to the calcogenic precursor compounds
(SeO 2 and Na 2 S 2 O 3 ), while CdS can also be obtained from organic solutions in
which elemental sulphur is the source of the chalcogenide component. Semiconductor 3DOM structures are all peculiar for photonic properties, especially due to
their light absorption in the infrared range.
Polymer deposition into colloidal templates. Colloidal templates make it possible
to deposit polymer films with a great variety. Apart from the various polymer
compositions (such as polypyrrole [310], poly(para-phenylene) [311] and poly(3,4ethylenedioxythiophene) [312], etc.), the different filling ratios applied allow a
morphological variety. Interestingly, polymers electrodeposited into multilayered
colloidal templates can be obtained in self-supporting form after the removal of the
templating particles, in spite of the softness of the polymer materials as compared to
metals.
11.3.4 The Double-Templating Method Based
on Nanosphere Lithography
In the methods discussed in the present chapter, the primary template is made from
colloidal particles. This template is filled up with a suitable material that makes an
inverse opal structure. Then, the primary template is removed, and the resulting empty
inverse opal structure is used as a secondary template. These procedures vary in which
step applies electrochemical deposition (the first, the second or both). The scheme
of the double-templating process and a few images of the resulting nanostructures
are presented in Fig. 11.17.