Askarova Gaukhar, Hesari Mahdi, Barman Koushik, Mirkin Michael V
Department of Chemistry and Biochemistry, Queens College, Flushing, New York 11367, United States.
The Graduate Center of CUNY, New York, New York 10016, United States.
ACS Appl Mater Interfaces. 2023 Oct 11;15(40):47168-47176. doi: 10.1021/acsami.3c13099. Epub 2023 Sep 27.
Particulate bismuth vanadate (BiVO) has attracted considerable interest as a promising photo(electro)catalyst for visible-light-driven water oxidation; however, overall water splitting (OWS) has been difficult to attain because its conduction band is too positive for efficient hydrogen evolution. Using photoscanning electrochemical microscopy (photo-SECM) with a chemically modified nanotip, we visualized for the first time the OWS at a single truncated bipyramidal microcrystal of phosphorus-doped BiVO. The tip simultaneously served as a light guide to illuminate the photocatalyst and an electrochemical nanoprobe to observe and quantitatively measure local oxygen and hydrogen fluxes. The obtained current patterns for both O and H agree well with the accumulation of photogenerated electrons and holes on {010} basal and {110} lateral facets, respectively. The developed experimental approach is an important step toward nanoelectrochemical mapping of the activity of photocatalyst particles at the subfacet level.
钒酸铋颗粒（BiVO）作为一种有前景的用于可见光驱动水氧化的光（电）催化剂引起了广泛关注；然而，由于其导带对于高效析氢来说过于正，所以难以实现整体水分解（OWS）。我们使用带有化学修饰纳米尖端的光扫描电化学显微镜（photo-SECM），首次在单个磷掺杂BiVO的截顶双锥微晶上可视化了OWS。该尖端同时充当照亮光催化剂的光导和观察并定量测量局部氧和氢通量的电化学纳米探针。所获得的O和H的电流模式分别与光生电子和空穴在{010}基面和{110}侧面上的积累情况非常吻合。所开发的实验方法是朝着在亚面水平对光催化剂颗粒活性进行纳米电化学绘图迈出的重要一步。
