a-fe 2 o 3 Photoanode and preparation method thereof

Abstract

The present invention relates to an alpha-Fe2O3 photo-anode and a preparation method thereof, the alpha-Fe2O3 photo-anode uses alpha-Fe2O3 as a light absorption layer, and uses Fe3O4, FeO and Fe as a conductive substrate. A direct high temperature fast oxidation method is used to prepare the photo-anode which comprises the conductive substrate and doped or non-doped alpha-Fe2O3, the doped or non-doped alpha-Fe2O3 as a light active layer is closely contacted with the conductive substrate, has good photoelectrocatalytic activity, under the AM1.5 standard test conditions, and relative to the reversible hydrogen electrode 1.23V, 0.63mA / cm2 can be achieved. Unlike publicly reported methods, the raw material of the method is easy to get, the whole photo-anode preparation process is fast, and large scale preparation is easy to realize. The photo-electrode can be used for the use of the decomposition of water for preparation of hydrogen, reduction of carbon dioxide, and the photocatalytic degradation of organic compounds, and the like.

Description

technical field [0001] The present invention relates to α-Fe for photoelectrochemical processes in solar energy utilization 2 o 3 A structure of a photoanode and a preparation method thereof. Background technique [0002] With the increasingly prominent energy problems and the resulting environmental problems, solar energy, as a sustainable clean energy, has been paid more and more attention to its conversion and utilization. As an important means of converting and utilizing solar energy, photoelectrochemistry has also made good progress in its research. Fujishima and Honda first reported single crystal TiO 2 The photoelectrode realizes photoelectrochemical water splitting under the applied bias voltage (Nature1972, 238, 37.). Since then, many semiconductor materials have been developed as photoanodes, such as WO 3 (Chemical Communications2012, 48, 729-731), ZnO (Adv. Funct. Mater. 2009, 19, 1849-1856), BiVO 4 (Chem.Commun.2003, 2908-2909), α-Fe 2 o 3 (J. Electrochem....

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Problems solved by technology

where α-Fe 2 o 3 Because of its wide sunlight absorption, suitable energy band position, environmental friendliness, abundant reserves and stable properties, it has been widely studied. At present, the preparation of α-Fe 2 o 3 The main methods of photoanode include atmospheric pressure chemical vapor deposition method, spray thermal decomposition method, solution chemical method, sol spraying method, etc. These methods first vapor-deposit, spin-coat, and self-assemble the iron precursor on the conductive substrate, and then undergo post-treatment to increase its close contact with the substrate, but the α-Fe prepared by these methods 2 o 3 The photoanode mainly has the following two problems: (1) The position of the conduction band is low, resulting in insufficient electron reducibility and a large bias voltage is required, that is, the turn-on potential is too positive; (2) The preparation method is time-consuming, complicated and expensive

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