Dr. Ho Won Jang, Department of Materials Science and Engineering, Seoul National University, Seoul.

Speech Title: Efficient Water Splitting Cascade Photoanodes with Ligand Engineered Oxygen Evolution Co-catalysts

Abstract: We firstly demonstrate the ligand engineering effect of manganese oxide co-catalyst nanoparticles (MnO NPs) on bismuth vanadate (BiVO₄)-based cascade anodes, and achieve a remarkably enhanced photocurrent density of 6.25 mA/cm² at the 1.23 V versus reversible hydrogen electrode. It is the highest value among the previously reported BiVO₄-based anodes. We verified that 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 intrinsic dipole of the ligand. Combined spectroscopic analysis and electrochemical study revealed the clear relationship between the surface structure driven by the ligand treatment and the band edge positions of MnO NPs for photoelectrochemical water oxidation. Our proposed concept of the ligand engineered nanoparticles has considerable potential in various photocatalytic semiconductors and suggests a way to explore new efficient solar water splitting system.