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Exfoliated NiFe Layered Double Hydroxide Cocatalyst for Enhanced Photoelectrochemical Water Oxidation with Hematite Photoanode
Author(s) -
Park Yoon Bin,
Kim Ju Hun,
Jang Youn Jeong,
Lee Jin Ho,
Lee Min Hee,
Lee Byeong Jun,
Youn Duck Hyun,
Lee Jae Sung
Publication year - 2019
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201801490
Subject(s) - photocurrent , hydroxide , passivation , exfoliation joint , materials science , water splitting , hematite , electrochemistry , monolayer , photoelectrochemistry , chemical engineering , electrode , inorganic chemistry , photocatalysis , chemistry , nanotechnology , optoelectronics , layer (electronics) , graphene , catalysis , metallurgy , engineering , biochemistry
In photoelectrochemical (PEC) water oxidation, a low onset potential and a high photocurrent are desired and a cocatalyst on the photoanode could improve the performance. For better use of a NiFe layered double hydroxide (LDH) cocatalyst, concept of exfoliation is applied. Exfoliation gives higher electrochemical surface area and better water oxidation kinetics, which is reflected in improved charge injection efficiency at low bias potentials. Exfoliated NiFe LDH shows increased photocurrent density by 50 % at 1.0 V RHE and reduced onset potential by 140 mV relative to those of stacked bulk LDH under 1 sun illumination, making it a much more effective cocatalyst for α‐Fe 2 O 3 photoanode. The intensity modulated photocurrent spectroscopy shows that the improved photocurrents and early onset potentials of exfLDH/α‐Fe 2 O 3 photoanode are attributed to fast charge transfer and, more importantly, suppressed charge recombination due to passivation of α‐Fe 2 O 3 surface by the LDH monolayer sheet.