Visible-light-induced photodissolution of α-Fe2O3 powder in the presence of chloride anions

Photodissolution of lepidocrocite (γ-FeOOH) in the presence of desferrioxamine B and aerobactin

“…These results are in agreement with a previous study in which the formation of Fe(II) was observed in irradiated lepidocrocite suspensions at pH 4 and 0.01 M ionic strength (Waite and Morel, 1984). The ability of some iron (hydr)oxides to form Fe(II) by intrinsic photoreductive mechanisms has been reported in recent years (Waite and Morel, 1984;Graetzel et al, 1985;Cunningham et al, 1988;Siffert and Sulzberger, 1991). Photoelectrons and photoholes generated in the semiconducting bulk may be scavenged at the surface leading to reduction of surface Fe(III) and oxidation of coordinated water or hydroxyl groups to hydroxyl radicals ( Å OH).…”

Light-induced hydrogen formation and photo-uptake of oxygen in colloidal suspensions of α-Fe2O3

“…In order to fully appreciate the role played by several of the oxide properties of a-Fe,O,, further redox reactions of powder and colloidal a-Fe,O, are examined along the lines of work previously reported. 15 Moreover, both electronically excited states and surface sites in a-Fe,O, of small dimensions may play an important role in redox processes involving these particles. The present study will focus on charge-carrier-induced reactions, in particular the generation of hydrogen and the photo-uptake of 0,.…”

Ni(OH)2 as Hole Mediator for Visible Light-Induced Urea Splitting

“…Here we extend the light absorption of the TiO 2 –Ni­(OH) 2 photoelectrode through photosensitization with CdS nanocrystals. CdS-sensitized TiO 2 has been researched extensively as photoanode in quantum dot sensitized solar cells. − CdS was also an early candidate for solar water splitting, given its straddled conduction and valence band positions relative to the water reduction and oxidation potentials. − However, OER cannot compete with the water-mediated photocorrosion reaction at the electrode–electrolyte interface, leading to electrode disintegration and failure. − The current approach represents a maiden effort in developing a midband gap semiconductor-catalyst architecture (CdS–Ni­(OH) 2 ) that can harness urea as sacrificial electron donor for the sustainable production of hydrogen by side-stepping OER. We probed the charge-carrier transfer and recombination kinetics to provide insight into the photoelectrochemical performance of the semiconductor-catalyst architecture.…”