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Hierarchical TiO 2 Photoanodes with Spatial Charge Separation for Efficient Oxygen Evolution Reaction
Author(s) -
Dong Guojun,
Cheng Xiang,
Bi Yingpu
Publication year - 2021
Publication title -
solar rrl
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.544
H-Index - 37
ISSN - 2367-198X
DOI - 10.1002/solr.202000449
Subject(s) - photocurrent , oxygen evolution , water splitting , nanorod , materials science , tin dioxide , substrate (aquarium) , tin oxide , nanotechnology , chemical engineering , electron transfer , oxygen , doping , photocatalysis , optoelectronics , catalysis , photochemistry , electrode , chemistry , electrochemistry , biochemistry , oceanography , geology , engineering , metallurgy , organic chemistry
Charge separation and transfer are crucial to determine photoelectrochemical (PEC) water splitting performance. Herein, a hierarchical bottom‐up approach for fabricating TiO 2 nanorod arrays with an Au nanolayer and Sn 3 O 4 cocatalysts is demonstrated. The hierarchical Sn 3 O 4 /TiO 2 /Au photoanode exhibits a significantly enhanced photocurrent density of 2.5 mA cm −2 at 1.23 V RHE under AM 1.5G irradiation, which is about 5 times higher than that of pristine TiO 2 (0.5 mA cm −2 at 1.23 V RHE ). The significantly enhanced PEC properties are attributed to the spatial charge separation among Au nanolayer and Sn 3 O 4 cocatalysts. More specifically, the bottom Au nanolayer can accelerate the electron transfer from TiO 2 to fluorine doped tin dioxide (FTO) substrate, and the surface Sn 3 O 4 nanoflakes can effectively capture holes and provide abundant active sites for oxygen‐evolution reaction. These demonstrations may offer a new insight for rational design and construction of highly efficient TiO 2 ‐based PEC devices for solar water splitting.