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Formation of an electron hole doped film in the α-Fe2O3 photoanode upon electrochemical oxidation


, : Formation of an electron hole doped film in the α-Fe2O3 photoanode upon electrochemical oxidation. Physical Chemistry Chemical Physics 15(5): 1443-1451

Solar hydrogen generation by water splitting in photoelectrochemical cells (PEC) is an appealing technology for a future hydrogen economy. Hematite is a prospective photoanode material in this respect because of its visible light conjugated band gap, its corrosion stability, its environmentally benign nature and its low cost. Its bulk and surface electronic structure has been under scrutiny for many decades and is considered critical for improvement of efficiency. In the present study, hematite films of nominally 500 nm thickness were obtained by dip-coating on fluorine doped tin oxide (FTO) glass slides and then anodised in 1 molar KOH at 500, 600, and 700 mV for 1, 10, 120 and 1440 minutes under dark conditions. X-ray photoelectron spectra recorded at the Fe 3p resonant absorption threshold show that the e(g) transition before the Fermi energy, which is well developed in the pristine hematite film, becomes depleted upon anodisation. The spectral weight of the e(g) peak decreases with the square-root of the anodisation time, pointing to a diffusion controlled process. The speed of this process increases with the anodisation potential, pointing to Arrhenius behaviour. Concomitantly, the weakly developed t(2g) peak intensity becomes enhanced in the same manner. This suggests that the surface of the photoanode contains Fe(2+) species which become oxidized toward Fe(3+) during anodisation. The kinetic behaviour derived from the experimental data suggests that the anodisation forms an electron hole doped film on and below the hematite surface.

US$19.90

PMID: 23165453

DOI: 10.1039/c2cp42597a


Other references

Hasinoff, B.B.; Takeda, K.; Ferrans, V.J.; Yu, Z-Xi., 2002: The doxorubicin cardioprotective agent dexrazoxane (ICRF-187) induces endopolyploidy in rat neonatal myocytes through inhibition of DNA topoisomerase II. Dexrazoxane (ICRF-187), which is clinically used to reduce doxorubicin-induced cardiotoxicity, is also a potent catalytic inhibitor of DNA topoisomerase II. In this study we showed that dexrazoxane inhibited the division of neonatal rat ventricula...

Bronger A.; Pant R.K., 1985: Micromorphology and genesis of some selected loess profiles in the Kashmir Valley and their relevance to stratigraphy and palaeoclimate. 6: 131-140 1985

Husain O.A.N., 1990: Quality control in a cancer screening program. Bonk, U (Ed ) Beitraege Zur Onkologie, Band 38 Aktuelle Klinische Zytologie; (Contributions to Oncology, Vol 38 Current Clinical Cytology) X+349p S Karger Ag: Basel, Switzerland; New York, New York, Usa Illus 169-174

Reinefeld, E.B.iesener, K., 1977: Enzymatic determination of formic acid and its use in molasses. Zucker 30 (12) 650-652

Kaplan, M.W., 1981: Light cycle--dependent axial variations in frog rod outer segment structure. Polarized light microscopy reveals that the structural parameters of Rana pipiens rod outer segments (ROS) are not uniform along the cell axis. In addition to a pronounced birefringence (delta n) gradient found in the basal half of most ROS, perio...

Hon, A.K.; Maloney, L.T.; Landy, M.S., 1996: The influence function for interpolation of sampled parabolic contours. Investigative Ophthalmology & Visual Science 37(3): S170

Inasaridze, K.; Sikharulidze, G.; Malishava, T.; Zviadadze, M., 2006: Attentional disorder in vascular dementia. Clinical trials in vascular cognitive impairment are in their infancy. The current narrow definitions of vascular dementia (VaD) should be broadened. VaD is characterised by a specific cognitive profile involving preserved memory with impairments...

Nakata, Y.; Suzuki, S.; Kawai, S.; Hirai, M.; Shinjo, K., 1975: Effects of lumbar sympathectomy on thromboangiitis obliterans. The clinical response to lumbar sympathectomy has been reported. The incidence of improvement was as follows: Coldness 52 percent, ulcer 58 percent, rest pain 64 percent, and claudication 31 percent, respectively. The blood flow in the anterior ti...

Hertzer, N.R., 1983: Teflon reinforcement of an uninterrupted aortic anastomosis. In the experience of the author, Teflon reinforcement of an uninterrupted aortic anastomosis has proved to be a rapid and reliable method to avoid excessive blood loss during reconstruction of the abdominal aorta with a prosthetic arterial graft....

Francis, P.C.; Grothe, D.W.; Scheuring, J.C., 1986: Chronic toxicity of 4-nitrophenol to Daphnia magna Straus under statis-renewal and flow-through conditions. Bulletin of Environmental Contamination and Toxicology 36(5): 730-737