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Composite of Cobalt‐C 3 N 4 on TiO 2 Nanorod Arrays as Co‐catalyst for Enhanced Photoelectrochemical Water Splitting
Author(s) -
Li Yuangang,
Shang Weike,
Li Huajing,
Yang Mengru,
Shi Shaosen,
Li Jin,
Huang Chenyu,
Zhou Anning
Publication year - 2021
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202100916
Subject(s) - photocurrent , nanorod , water splitting , catalysis , cobalt , materials science , hydrothermal circulation , valence band , chemical engineering , nanotechnology , band gap , photocatalysis , chemistry , optoelectronics , biochemistry , engineering , metallurgy
TiO 2 @Co‐C 3 N 4 nanorod arrays were prepared by drop coating and hydrothermal method. The Photoelectrochemical (PEC) performance of TiO 2 @Co‐C 3 N 4 nanorod arrays can be tuned by the amount of Co‐C 3 N 4 coated. When the amount of Co‐C 3 N 4 reached about 0.75 μg/cm 2 , the PEC performance of TiO 2 @Co‐C 3 N 4 reached the maximum. The results show that the photocurrent density of TiO 2 @Co‐C 3 N 4 nanorod array reaches 1.79 mA/cm 2 at 1.23 V RHE , which is about 2.3 times of that from TiO 2 @g ‐C 3 N 4 . And the PEC device has good stability and the photocurrent density remains no decline after 10 hours of continuous operation. Co atoms coordinated with g ‐C 3 N 4 could act as a co‐catalyst for water oxidation, and a possible mechanism is proposed for water oxidation based on careful analysis of the detailed results. The holes photogenerated by excited electrons oxidize Co atoms from Co II to Co III and Co IV , and then these high‐valence cobalt species accelerate the kinetics of water oxidation. In addition, Co‐C 3 N 4 not only can promote the charge transfer but also improve the overall energy conversion efficiency of the PEC device.