TY - JOUR
T1 - Synergistic Effects of Surface Passivation and Charge Separation to Improve Photo-electrochemical Performance of BiOI Nanoflakes by Au Nanoparticle Decoration
AU - Chang, An Mi
AU - Chen, Yu Hung
AU - Lai, Chien Chih
AU - Pu, Ying Chih
N1 - Funding Information:
We acknowledge the financial support from the Ministry of Science and Technology of Taiwan (MOST) under grant MOST-109-2113-M-024-002. We gratefully acknowledge the support of soft-matter TEM, JEOL JEM-2100F Cs STEM, and HR-SEM (Hitachi SU8000 and EDS: Bruker XFlash5010) equipment belonging to the Instrument Center of National Cheng Kung University.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/2/3
Y1 - 2021/2/3
N2 - We demonstrate that the photoactivity of bismuth oxyiodide (BiOI) nanoflake (NF) photocathodes in photo-electrochemical (PEC) water splitting can be significantly enhanced by about 24-fold by thermal calcination under an air atmosphere and then surficial decoration of Au nanoparticles (NPs). To understand the key factors affecting the PEC efficiency in Au NP-decorated BiOI NF photoelectrodes, incident photon-to-current conversion efficiency, electrochemical impedance spectroscopy, photovoltage, and electrochemically active surface area measurements were performed. The analytic results presented that thermal calcining could produce mesopores, increasing active sites on the surface of BiOI NFs. In addition, the synergistic effects of surface-state passivation and charge separation were observed for the surficial Au NP decoration on BiOI NFs. Transient absorption spectroscopy coupled with PEC measurements confirmed that the lifetime of photogenerated electrons on the conduction band of BiOI NFs can be prolonged by Au NP decoration, resulting in higher probability to carry out water reduction. The current investigation presents important insights into the mechanism of charge carrier dynamics in metal-semiconductor nano-heterostructures, which is contributive to develop photoelectrode materials in solar fuel production.
AB - We demonstrate that the photoactivity of bismuth oxyiodide (BiOI) nanoflake (NF) photocathodes in photo-electrochemical (PEC) water splitting can be significantly enhanced by about 24-fold by thermal calcination under an air atmosphere and then surficial decoration of Au nanoparticles (NPs). To understand the key factors affecting the PEC efficiency in Au NP-decorated BiOI NF photoelectrodes, incident photon-to-current conversion efficiency, electrochemical impedance spectroscopy, photovoltage, and electrochemically active surface area measurements were performed. The analytic results presented that thermal calcining could produce mesopores, increasing active sites on the surface of BiOI NFs. In addition, the synergistic effects of surface-state passivation and charge separation were observed for the surficial Au NP decoration on BiOI NFs. Transient absorption spectroscopy coupled with PEC measurements confirmed that the lifetime of photogenerated electrons on the conduction band of BiOI NFs can be prolonged by Au NP decoration, resulting in higher probability to carry out water reduction. The current investigation presents important insights into the mechanism of charge carrier dynamics in metal-semiconductor nano-heterostructures, which is contributive to develop photoelectrode materials in solar fuel production.
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U2 - 10.1021/acsami.0c18430
DO - 10.1021/acsami.0c18430
M3 - Article
C2 - 33464818
AN - SCOPUS:85100243138
SN - 1944-8244
VL - 13
SP - 5721
EP - 5730
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 4
ER -
