Improved Photoelectrochemical Activity of CaFe2O4/BiVO4 Heterojunction Photoanode by Reduced Surface Recombination in Solar Water Oxidation

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• 作者：Eun Sun Kim ; Hyun Joon Kang ; Ganesan Magesh ; Jae Young Kim ; Ji-Wook Jang ; Jae Sung Lee
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：October 22, 2014
• 年：2014
• 卷：6
• 期：20
• 页码：17762-17769
• 全文大小：446K
• ISSN：1944-8252

文摘

A bismuth vanadate photoanode was first fabricated by the metal鈥搊rganic decomposition method and particles of calcium ferrite were electrophoretically deposited to construct a heterojunction photoanode. The characteristics of the photoanodes were investigated in photoelectrochemical water oxidation under simulated 1 sun (100 mW cm^鈥?) irradiation. Relative to the pristine BiVO₄ anode, the formation of the heterojunction structure of CaFe₂O₄/BiVO₄ increased the photocurrent density by about 60%. The effect of heterojunction formation on the transfer of charge carriers was investigated using hydrogen peroxide as a hole scavenger. It was demonstrated that the heterojunction formation reduced the charge recombination on the electrode surface with little effect on bulk recombination. The modification with an oxygen evolving catalyst, cobalt phosphate (Co-Pi), was also beneficial for improving the efficiency of CaFe₂O₄/BiVO₄ heterojunction photoanode mainly by increasing the stability.

Keywords:

bismuth vanadate; calcium ferrite; heterojunction photoanode; photoelectrochemical cell; water splitting