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The synthesis and electrochemical properties of highly ordered mesoporous T-[Nb.sub.2][O.sub.5], L-[Ta.sub.2][O.sub.5], and TaNb[O.sub.5] solid solution thin film with iso-oriented layered nanocrystalline domains are described. The studies have shown that the group V transition metal oxides can be produced with a high degree of crystallographic alignment on virtually any substrate in contrast to classical solution-phase epitaxy that needs the use of a single-crystalline substrate to achieve oriented crystal growth.

We describe the general synthesis of submicrometer-thick rare-earth/lanthanide sesquioxide (RE2O3) films with tailorable pore and grain sizes via polymer templating of hydrated chloride salt precursors. Mesostructured RE2O3 (RE = Sm, Tb-Lu) ceramics with cubic pore symmetry and high surface area (SBET ≥ 50 m² g-1) were prepared using different diblock copolymer structure-directing agents and were characterized by a combination of electron microscopy, in situ and ex situ grazing incidence small-angle X-ray scattering, N2 physisorption, X-ray photoelectron spectroscopy, X-ray diffraction including Rietveld refinement, and ultraviolet-visible spectroscopy. In the present work, we specifically focus on Dy2O3 and Yb2O3 and use both of these materials as model systems to study, among other things, the film formation and microstructure. Our research data collectively demonstrate that (1) record pore sizes of up to 42 nm in diameter can be achieved without the need for swelling agents, (2) the nanostructure can be preserved up to 1000 °C for the heavier oxides, (3) the sizes of the optical band gaps (4.9-5.6 eV) are comparable to those reported for single crystals, (4) the sol-gel-derived materials are single phase and adopt the C-type crystal structure, and (5) the grain growth is virtually linear, with domain sizes in the range of 3-16 nm. We also show that, except for Yb2O3, all of the samples have a fiber texture and the preferred orientation is significant in Sm2O3 and Lu2O3 films (March parameter G2 < 0.1). Overall, the synthesis parameters described in this work provide a blueprint for the preparation of thermally stable rare-earth oxide ceramics with both a mesoporous morphology and iso-oriented nanocrystalline walls. [ABSTRACT FROM AUTHOR]

In this paper, we report on ordered mesoporous NiFe2O4 thin films synthesized via co-assembly of hydrated ferric nitrate and nickel chloride with an amphiphilic diblock copolymer, referred to as KLE. We establish that the NiFe2O4 samples are highly crystalline after calcination at 600 °C, and that the conversion of the amorphous inorganic framework comes at little cost to the ordering of the high quality cubic network of pores averaging 16 nm in diameter. We further show that the synthesis method employed in this work can be readily extended to other ferrites, such as CoFe2O4, CuFe2O4, MgFe2O4, and ZnFe2O4, which could pave the way for innovative device design. While this article focuses on the self-assembly and characterization of these materials using various state-of-the-art techniques, including electron microscopy, grazing incidence small-angle X-ray scattering (GISAXS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), as well as UV-vis and Raman spectroscopy, we also examine the electrochemical properties and show the benefits of combining a continuous mesoporosity with nanocrystalline films. KLE-templated NiFe2O4 electrodes exhibit reasonable levels of lithium ion storage at short charging times which stem from facile pseudocapacitance. [ABSTRACT FROM AUTHOR]

Nanocrystalline nickel molybdate (NiMoO(4)) thin film electrodes with a 3D honeycomb structure of uniform 17 nm diameter pores were successfully produced through facile polymer templating strategies. These novel sol-gel type materials exhibit enhanced lithium ion storage capabilities, and thus show promise for battery applications.

Combining sol-gel chemistry with polymer templating strategies enables production of CuFe(2)O(4) thin films with both an ordered cubic network of 17 nm diameter pores and tunable spinel domain sizes. These nanocrystalline materials contain only minor structural defects with λ = 0.85 ± 0.02 and exhibit multiple functionalities, including superparamagnetic behavior (T(B)≈ 310 K) and redox- and photoactivity., (This journal is © The Royal Society of Chemistry 2012)