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Electrochemical Evaluation for Multiple Functions of Pt‐loaded TiO 2 Nanoparticles Deposited on a Photocathode
Author(s) -
Kageshima Yosuke,
Fujita Takumi,
Takagi Fumiaki,
Minegishi Tsutomu,
Teshima Katsuya,
Domen Kazunari,
Amao Yutaka,
Nishikiori Hiromasa
Publication year - 2019
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201901453
Subject(s) - photocathode , materials science , electrochemistry , electrolyte , photocurrent , electrode , water splitting , hydrogen production , chemical engineering , optoelectronics , hydrogen , photocatalysis , chemistry , catalysis , physics , electron , biochemistry , organic chemistry , quantum mechanics , engineering
Pt‐loaded TiO 2 nanoparticles (Pt/TiO 2 ) were deposited on a near‐infrared responsive photocathode as a reaction field for the photoelectrochemical (PEC) hydrogen evolution from water. The multiple functions of the Pt/TiO 2 layer for improving the PEC performances were evaluated by electrochemical methods. Considering the electrochemically active surface area (ECSA) of Pt, the Pt/TiO 2 surface modification was revealed to increase the number of active sites (Pt), resulting in a decreased current density per active site. Consequently, the potential of the Pt/TiO 2 ‐modified photocathode surface during the PEC reaction was expected to be located around 38–46 mV vs. a reversible hydrogen electrode (mV RHE ), while that of the unmodified one was negatively shifted to around 13 mV RHE . In addition, the TiO 2 layer also functioned to block the migration of holes to the photocathode‐electrolyte interface due to its deep valence band position, as well as to improve the wettability of the photocathode surface during light irradiation. These combined effects of the TiO 2 , as a transparent and conductive support, enhanced the photocurrent, and stability of the photocathode.