Open AccessEfficient Water Splitting Cascade Photoanodes with Ligand‐Engineered MnO Cocatalysts
Author(s) -
Lee Mi Gyoung,
Jin Kyoungsuk,
Kwon Ki Chang,
Sohn Woonbae,
Park Hoonkee,
Choi Kyoung Soon,
Go Yoo Kyung,
Seo Hongmin,
Hong Jung Sug,
Nam Ki Tae,
Jang Ho Won
Publication year - 2018
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201800727
Subject(s) - water splitting , bismuth vanadate , photocurrent , ligand (biochemistry) , materials science , semiconductor , density functional theory , dipole , chemical physics , chemistry , optoelectronics , computational chemistry , photocatalysis , biochemistry , receptor , catalysis , organic chemistry
The band edge positions of semiconductors determine functionality in solar water splitting. While ligand exchange is known to enable modification of the band structure, its crucial role in water splitting efficiency is not yet fully understood. Here, ligand‐engineered manganese oxide cocatalyst nanoparticles (MnO NPs) on bismuth vanadate (BiVO 4 ) anodes are first demonstrated, and a remarkably enhanced photocurrent density of 6.25 mA cm −2 is achieved. It is close to 85% of the theoretical photocurrent density (≈7.5 mA cm −2 ) of BiVO 4 . Improved photoactivity is closely related to the substantial shifts in band edge energies that originate from both the induced dipole at the ligand/MnO interface and the intrinsic dipole of the ligand. Combined spectroscopic analysis and electrochemical study reveal the clear relationship between the surface modification and the band edge positions for water oxidation. The proposed concept has considerable potential to explore new, efficient solar water splitting systems.