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Indexed by:期刊论文

Date of Publication:2017-12-01

Journal:FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING

Included Journals:Scopus、SCIE、EI

Volume:11

Issue:6

ISSN No.:2095-2201

Key Words:Si; alpha-Fe2O3; Photoelectrochemistry; Photogenerated charge separation

Abstract:The spontaneous oxidation process of pristine silicon (Si) limits its application as photocatalyst or electrode in aqueous solution or moist air. Covering a protection layer on Si surface is an effective approach to overcome this disadvantage. In this paper, alpha-Fe2O3 is demonstrated to be an excellent alternative as a protection material. alpha-Fe2O3 layer was deposited around each p-type Si micropillar (SiMP) in well-ordered array by chemical bath deposition method. The diameter of SiMP was 5 mm and the thickness of alpha-Fe2O3 layer was about 20 nm. The photoeletrochemical stability of SiMP/alpha-Fe2O3 was proved by 10 circles cyclic voltammetry testing. Compared with SiMP, its optical absorption and photocurrent density improved 2 times and 4 times, respectively, and its onset potential for hydrogen evolution moved positively about 0.4 V. These improved performances could be ascribed to the enhanced photogenerated-charge-separation efficiency deriving from built-in electric field at the interface between Si and alpha-Fe2O3. The above results show an effective strategy to utilize Si material as photocatalyst or electrode in aqueous solution or moist air. (C) Higher Education Press and Springer-Verlag Berlin Heidelberg 2017