Photoelectrochemical activity of as-grown, α-Fe2O3 nanowire array electrodes for water splitting.
Nanotechnology
; 23(19): 194009, 2012 May 17.
Article
en En
| MEDLINE
| ID: mdl-22539110
Undoped hematite nanowire arrays grown using plasma oxidation of iron foils show significant photoactivity (~0.38 mA cm(-2) at 1.5 V versus reversible hydrogen electrode in 1 M KOH). In contrast, thermally oxidized nanowire arrays grown on iron exhibit no photoactivity due to the formation of a thick (>7 µm Fe(1-x)O) interfacial layer. An atmospheric plasma oxidation process required only a few minutes to synthesize hematite nanowire arrays with a 15 µm interfacial layer of magnetite between the nanowire arrays and the iron substrate. An amorphous oxide surface layer on hematite nanowires, if present, is shown to decrease the resulting photoactivity of as-synthesized, plasma grown nanowire arrays. The photocurrent onset potential is improved after removing the amorphous surface on the nanowires using an acid etch. A two-step method involving high temperature nucleation followed by growth at low temperature is shown to produce a highly dense and uniform coverage of nanowire arrays.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Nanotechnology
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido