“Double-Use” Strategy for Improving the Photoelectrochemical Performance of BiVO 4 Photoanodes Using a Cobalt-Functionalized Polyoxotungstate

作者：Fan Feng, Dariusz Mitoraj, Ekemena O. Oseghe, Carsten Streb, Radim Beránek · 发表于：ACS Applied Materials & Interfaces · 年份：2024 · DOI：10.1021/acsami.4c21125 · 被引用次数：7 · 研究领域：Advanced Photocatalysis Techniques、Polyoxometalates: Synthesis and Applications、Copper-based nanomaterials and applications

Doping and surface-modification are well-established strategies for the performance enhancement of bismuth vanadate (BiVO 4 ) photoanodes in photoelectrochemical (PEC) water splitting devices. Herein, a “double-use” strategy for the development of high-performance BiVO 4 photoanodes for solar water splitting is reported, where a molecular cobalt–phosphotungstate (CoPOM = Na 10 [Co 4 (H 2 O) 2 (PW 9 O 34 ) 2 ]) is used both as a bulk doping agent as well as a surface-deposited water oxidation cocatalyst. The use of CoPOM for bulk doping of BiVO 4 is shown to enhance the electrical conductivity and improve the charge separation efficiency, resulting in the enhancement of the maximum applied-bias photoconversion efficiency (ABPE) by a factor of ∼18 to 0.54% at 0.87 V vs. RHE, as compared to pristine BiVO 4 (0.03% at 1.04 V vs. RHE). The ratio of W/Co on the surface of the photoanode is related to the activity and stability. In addition, modification of CoPOM-doped BiVO 4 with CoPOM as a surface cocatalyst enhances the hole extraction and improves the water oxidation kinetics, resulting in the overall enhancement of the ABPE to 0.79% (at 0.82 V vs. RHE), i.e., by a factor of ∼26 with respect to pristine BiVO 4 . This study establishes the “double-use” strategy involving CoPOMs as an effective, straightforward, and easily scalable approach for the development of high-quality photoanodes for solar water splitting and highlights the future potential of utilizing well-designed polyox...