No abstract

No abstract

No abstract

No abstract

No abstract

No abstract

The Mn-oxide/Nb:SrTiO3 photoelectrode for oxygen evolution reaction was investigated by in situ Mn K-edge XAFS spectroscopy under UV irradiation. The oxidization of the Mn oxide was observed via photoexcited carrier transfer, which results in the positive potential shift of the Mn oxide cocatalyst toward oxygen evolution reaction.

Photoexcited hole transfer to MnO x cocatalysts on SrTiO3 photoelectrodes was examined under controlled potential conditions during UV irradiation using in situ Mn K-edge X-ray absorption fine structure (XAFS) spectroscopy. The absorption edges of spectra were found to shift to higher energies during irradiation, indicating that MnO x cocatalysts were oxidized by the migration of photoexcited holes accompanied by a positive potential shift of the MnO x cocatalysts. This oxidation process was promoted by the application of a positive applied potential, suggesting that the photoexcited hole transfer was enhanced by upward band bending at the cocatalyst–photoelectrode interface. Structural changes of the MnO x cocatalyst were found to depend on the UV photon intensity; thus, the observations of photoexcited electron transfer by XAFS are associated with the photoelectrochemical activity during water splitting.