Abstract
Surface-oxygen-vacancy-promoted Z-scheme CeO2-AgI heterostructured photocatalysts were successfully fabricated via a hydrothermal route combined with a precipitation process. Surface oxygen vacancies were formed on the synthesized CeO2-AgI photocatalyst, as determined by X-ray photoelectron spectroscopy. These oxygen vacancies could extend the lifetime of the charge carriers and enhance the photocatalytic activity of these catalysts for rhodamine B (RhB) dye degradation. Among the as-synthesized photocatalysts, the 20 wt% CeO2-AgI (CA-2) nanocomposite demonstrated the highest photocatalytic activity towards the degradation of RhB with 3.28- and 29.8-fold higher activity than pure AgI and CeO2 nanostructures, respectively. In addition, to ensure the visible light photocatalytic activity of the CeO2-AgI nanocomposite, decomposition studies were performed using a colorless substrate such as phenol. The mechanism for the enhanced photocatalytic performance of the CeO2-AgI photocatalyst is proposed to be based on efficient separation of photogenerated electron-hole pairs through a Z-scheme system, in which oxygen vacancy states promote charge separation. Experiments using scavengers of reactive species combined with photoluminescence analysis provide significant evidence for the oxygen-vacancy-mediated Z-scheme mechanism of the photocatalyst. Moreover, the as-prepared oxygen-deficient CeO2-AgI photocatalysts exhibited excellent cycling stability.
| Original language | English |
|---|---|
| Pages (from-to) | 19341-19350 |
| Number of pages | 10 |
| Journal | RSC Advances |
| Volume | 6 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - 2016 Jan 1 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Chemical Engineering(all)
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Surface oxygen vacancy assisted electron transfer and shuttling for enhanced photocatalytic activity of a Z-scheme CeO2-AgI nanocomposite. / Islam, M. Jahurul; Reddy, D. Amaranatha; Choi, Jiha; Kim, Tae Kyu.
In: RSC Advances, Vol. 6, No. 23, 01.01.2016, p. 19341-19350.Research output: Contribution to journal › Article
TY - JOUR
T1 - Surface oxygen vacancy assisted electron transfer and shuttling for enhanced photocatalytic activity of a Z-scheme CeO2-AgI nanocomposite
AU - Islam, M. Jahurul
AU - Reddy, D. Amaranatha
AU - Choi, Jiha
AU - Kim, Tae Kyu
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Surface-oxygen-vacancy-promoted Z-scheme CeO2-AgI heterostructured photocatalysts were successfully fabricated via a hydrothermal route combined with a precipitation process. Surface oxygen vacancies were formed on the synthesized CeO2-AgI photocatalyst, as determined by X-ray photoelectron spectroscopy. These oxygen vacancies could extend the lifetime of the charge carriers and enhance the photocatalytic activity of these catalysts for rhodamine B (RhB) dye degradation. Among the as-synthesized photocatalysts, the 20 wt% CeO2-AgI (CA-2) nanocomposite demonstrated the highest photocatalytic activity towards the degradation of RhB with 3.28- and 29.8-fold higher activity than pure AgI and CeO2 nanostructures, respectively. In addition, to ensure the visible light photocatalytic activity of the CeO2-AgI nanocomposite, decomposition studies were performed using a colorless substrate such as phenol. The mechanism for the enhanced photocatalytic performance of the CeO2-AgI photocatalyst is proposed to be based on efficient separation of photogenerated electron-hole pairs through a Z-scheme system, in which oxygen vacancy states promote charge separation. Experiments using scavengers of reactive species combined with photoluminescence analysis provide significant evidence for the oxygen-vacancy-mediated Z-scheme mechanism of the photocatalyst. Moreover, the as-prepared oxygen-deficient CeO2-AgI photocatalysts exhibited excellent cycling stability.
AB - Surface-oxygen-vacancy-promoted Z-scheme CeO2-AgI heterostructured photocatalysts were successfully fabricated via a hydrothermal route combined with a precipitation process. Surface oxygen vacancies were formed on the synthesized CeO2-AgI photocatalyst, as determined by X-ray photoelectron spectroscopy. These oxygen vacancies could extend the lifetime of the charge carriers and enhance the photocatalytic activity of these catalysts for rhodamine B (RhB) dye degradation. Among the as-synthesized photocatalysts, the 20 wt% CeO2-AgI (CA-2) nanocomposite demonstrated the highest photocatalytic activity towards the degradation of RhB with 3.28- and 29.8-fold higher activity than pure AgI and CeO2 nanostructures, respectively. In addition, to ensure the visible light photocatalytic activity of the CeO2-AgI nanocomposite, decomposition studies were performed using a colorless substrate such as phenol. The mechanism for the enhanced photocatalytic performance of the CeO2-AgI photocatalyst is proposed to be based on efficient separation of photogenerated electron-hole pairs through a Z-scheme system, in which oxygen vacancy states promote charge separation. Experiments using scavengers of reactive species combined with photoluminescence analysis provide significant evidence for the oxygen-vacancy-mediated Z-scheme mechanism of the photocatalyst. Moreover, the as-prepared oxygen-deficient CeO2-AgI photocatalysts exhibited excellent cycling stability.
UR - http://www.scopus.com/inward/record.url?scp=84958982595&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84958982595&partnerID=8YFLogxK
U2 - 10.1039/c5ra27533d
DO - 10.1039/c5ra27533d
M3 - Article
AN - SCOPUS:84958982595
VL - 6
SP - 19341
EP - 19350
JO - RSC Advances
JF - RSC Advances
SN - 2046-2069
IS - 23
ER -