A Conformal Carbon Nanolayer Coated Fe2 O3 Cocatalyst for the Promoted Activity of Plasma-Sputtered BiVO4 Photoanode.

Abstract

To simultaneously improve the hole extraction ability of the BiVO4 photoanode and accelerate the surface reaction kinetics, herein, a carbon nanolayer conformally coated Fe2 O3 (C-Fe2 O3 ) as oxygen evolution catalyst (OEC) is loaded on the H2 plasma treated nanoporous BiVO4 (BVO(H2 )) surface by a hydrothermal reaction. It is found that the H2 plasma induced vacancies in BVO remarkably increases the conductivity, and the C-Fe2 O3 enables hole extraction from the bulk to the surface as well as efficient hole injection to the electrolyte. As a result, the C-Fe2 O3 /BVO(H2 ) photoanode achieves a photocurrent density of 4.4 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) and an ABPE value of 1.5 % at 0.68 V vs. RHE, which are 4.8-fold and 13-fold higher than that of BVO photoanode, respectively.