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

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.

Enhanced Surface Kinetics and Charge Transfer of BiVO4 Photoanodes by Rh2 O3 Cocatalyst Loading for Improved Solar Water Oxidation.

A Rh2 O3 /BiVO4 composite photoanode exhibits enhanced surface reaction kinetics and charge transfer efficiency, enabling a photocurrent density of ca. 3.5 mA/cm2 at 1.23 V (vs. RHE), which is about 3.89 times higher than that of the pristine BiVO4 , with a lower onset potential of 0.29 V (vs. RHE).