Enhancing Photoelectrochemical Water Oxidation Efficiency of WO3/α-Fe2O3 Heterojunction Photoanodes by Surface Functionalization with CoPd Nanocrystals

5 years ago

Enhancing Photoelectrochemical Water Oxidation Efficiency of WO3/α-Fe2O3 Heterojunction Photoanodes by Surface Functionalization with CoPd Nanocrystals

Piotr Kustrowski, Adam Slabon, Felix Schrader, Anna Rokicinska, Martin Davi, George Ogutu

Sunlight can be used to split water into hydrogen and oxygen by means of a photoelectrochemical (PEC) cell. Oxide nanostructures in heterojunction geometry, consisting of anisotropic WO3 nanostructures coated with a second semiconductor having a narrower band gap, such as α-Fe2O3, have emerged as prospective photoanodes. Herein, the integration of monodisperse CoPd nanocrystals (NCs) with α-Fe2O3 and WO3/α-Fe2O3 heterojunction semiconductor nanostructures for PEC water oxidation is reported. Depositing CoPd NCs on the surface of hematite leads to more stable photocurrent in comparison to the bare electrode, which indicates improved electron–hole separation at the semiconductor/electrolyte interface. Altering the surface of WO3/α-Fe2O3 photoanodes with CoPd NCs induces a cathodic shift of the onset potential and increases photocurrent density from 0.15 to 0.5 mA cm–2 during water oxidation at 1.23 V versus RHE under AM 1.5 G illumination (pH 7).WO3 nanostructures coated with a second, smaller-band-gap semiconductor such as α-Fe2O3 have emerged as prospective photoanodes. Depositing CoPd NCs on the surface of hematite leads to more stable photocurrents and a cathodic shift during photoelectrochemical water oxidation.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/ejic.201700952