New insights into water photooxidation on reductively pretreated hematite photoanodes.

It has been recently demonstrated that the photoactivity toward oxygen evolution of a number of n-type metal oxides can be substantially improved by a reductive electrochemical pretreatment. Such an enhancement has been primarily linked to the formation of low valent metal species that increase electrode conductivity. In this work, we report new insights into the electrochemical doping using highly ordered (110)-oriented hematite nanorods directly grown on FTO.

Modification of Hematite Electronic Properties with Trimethyl Aluminum to Enhance the Efficiency of Photoelectrodes.

The electronic properties of hematite were investigated by means of synchrotron radiation photoemission (SR-PES) and X-ray absorption spectroscopy (XAS). Hematite samples were exposed to trimethyl aluminum (TMA) pulses, a widely used Al-precursor for the atomic layer deposition (ALD) of Al2O3. SR-PES and XAS showed that the electronic properties of hematite were modified by the interaction with TMA.

Potentiostatic reversible photoelectrochromism: an effect appearing in nanoporous TiO2/Ni(OH)2 thin films.

In the field of energy saving, finding composite materials with the ability of coloring upon both illumination and change of the applied electrode potential keeps on being an important goal. In this context, chemical bath deposition of Ni(OH)2 into nanoporous TiO2 thin films supported on conducting glass leads to electrodes showing both conventional electrochromic behavior (from colorless to dark brown and vice versa) together with photochromism at constant applied potential. The latter phenomenon, reported here for the first time, is characterized by fast and reversible coloration upon UV illumination.