Photoanodes with Fully Controllable Texture: The Enhanced Water Splitting Efficiency of Thin Hematite Films Exhibiting Solely (110) Crystal Orientation.

Hematite, α-Fe2O3, is considered as one of the most promising materials for sustainable hydrogen production via photoelectrochemical water splitting with a theoretical solar-to-hydrogen efficiency of 17%. However, the poor electrical conductivity of hematite is a substantial limitation reducing its efficiency in real experimental conditions. Despite of computing models suggesting that the electrical conductivity is extremely anisotropic, revealing up to 4 orders of magnitude higher electron transport with conduction along the (110) hematite crystal plane, synthetic approaches allowing the sole growth in that direction have not been reported yet.

Molten o-H3PO4: A New Electrolyte for the Anodic Synthesis of Self-Organized Oxide Structures--WO3 Nanochannel Layers and Others.

We introduce the use of pure molten ortho-phosphoric acid (o-H3PO4) as an electrolyte for self-organizing electrochemistry. This electrolyte allows for the formation of self-organized oxide architectures (one-dimensional nanotubes, nanochannels, nanopores) on metals such as tungsten that up to now were regarded as very difficult to grow self-ordered anodic oxide structures. In this work, we show particularly the fabrication of thick, vertically aligned tungsten oxide nanochannel layers, with pore diameter of ca.

NH₃ treatment of TiO₂ nanotubes: from N-doping to semimetallic conductivity.

In the present work we show that a suitable high temperature ammonia treatment allows for the conversion of single-walled TiO2 nanotube arrays not only to a N-doped photoactive anatase material (which is already well established), but even further into fully functional titanium nitride (TiN) tubular structures that exhibit semimetallic conductivity.

Enhanced photoelectrochemical water splitting efficiency of a hematite-ordered Sb:SnO2 host-guest system.

Host-guest systems such as hematite/SnO2 have attracted a great deal of interest as photoanodes for photoelectrochemical water splitting. In the present work we form an ordered porous tin oxide layer formed by self-organizing anodization of Sn films on a FTO substrate. Subsequently the anodic tin oxide nanostructure is doped with antimony (ATO) by a simple impregnation and annealing treatment, and then decorated with hematite using anodic deposition.

Ultra fast electrochromic switching of nanoporous tungsten-tantalum oxide films.

Self-organized nanoporous oxide layers were grown on a W-Ta alloy by electrochemical anodization. These nanostructured mixed oxide layers show an ultra-fast electrochromic switching kinetics. Compared with porous WO(3) nanostructures more than 10 times higher switching frequencies are reached along with a significantly enhanced lifetime and cyclability.