TY - JOUR
T1 - Porous TiO2 adsorbed with squaraine dye as visible-light-responsive photocatalyst
AU - Yamazaki, Suzuko
AU - Sonoda, Kotoe
AU - Maruoka, Kiyotaka
AU - Yamazaki, Yukari
AU - Naragino, Hiroshi
AU - Honda, Kensuke
AU - Murafuji, Toshihiro
AU - Sumimoto, Michinori
N1 - Funding Information:
We thank Yamaguchi University for funding us in YU Project for the Formation of the Core Research Center. We thank Yamaguchi University Science Research Center for the NMR and the XRD measurements.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - The present paper reports the development of TiO2 photocatalysts adsorbed with squaraine dyes for the utilization of visible light. We synthesized 1,3-bis(3,3-dimethyl-2-methylene indolenine)squaraine (ISQ) and its derivatives having two COOH (ISQ-(COOH)2), COOH and COOC4H9 (ISQ-COOHCOOBu) and two COOC4H9 groups (ISQ-(COOBu)2) at both ends. We used porous TiO2 which was synthesized by a sol–gel method and possessed a specific surface area of 229 m2 g−1. ISQ without an anchoring group of COOH hardly adsorbed and the number of the adsorbed ISQ-(COOH)2 or ISQ-COOHCOOBu per gram of TiO2 was estimated to be (5.53 ± 0.74) × 10-5 or (5.93 ± 0.68) × 10-5 mol g−1, respectively. Photocatalytic degradation of methyl orange (MO) was performed on TiO2 adsorbed with ISQ-(COOH)2 or ISQ-COOHCOOBu in the range of (0.12–5.4) × 10-5 or (0.15–6.2) × 10-5 mol g−1. The degradation rate increased drastically with an increase in the adsorbed amounts of these dyes less than 1.7 × 10-5 mol g−1 but then increased gradually up to ca. 6 × 10-5 mol g−1. The electrochemical measurements revealed that the photogenerated electron was transferred from these dyes to the conduction band of TiO2. No MO was degraded on TiO2 adsorbed with ISQ-(COOH)2 in the nitrogen atmosphere under VL irradiation. We proposed the degradation mechanism of MO on TiO2 adsorbed with ISQ-(COOH)2 or ISQ-COOHCOOBu.
AB - The present paper reports the development of TiO2 photocatalysts adsorbed with squaraine dyes for the utilization of visible light. We synthesized 1,3-bis(3,3-dimethyl-2-methylene indolenine)squaraine (ISQ) and its derivatives having two COOH (ISQ-(COOH)2), COOH and COOC4H9 (ISQ-COOHCOOBu) and two COOC4H9 groups (ISQ-(COOBu)2) at both ends. We used porous TiO2 which was synthesized by a sol–gel method and possessed a specific surface area of 229 m2 g−1. ISQ without an anchoring group of COOH hardly adsorbed and the number of the adsorbed ISQ-(COOH)2 or ISQ-COOHCOOBu per gram of TiO2 was estimated to be (5.53 ± 0.74) × 10-5 or (5.93 ± 0.68) × 10-5 mol g−1, respectively. Photocatalytic degradation of methyl orange (MO) was performed on TiO2 adsorbed with ISQ-(COOH)2 or ISQ-COOHCOOBu in the range of (0.12–5.4) × 10-5 or (0.15–6.2) × 10-5 mol g−1. The degradation rate increased drastically with an increase in the adsorbed amounts of these dyes less than 1.7 × 10-5 mol g−1 but then increased gradually up to ca. 6 × 10-5 mol g−1. The electrochemical measurements revealed that the photogenerated electron was transferred from these dyes to the conduction band of TiO2. No MO was degraded on TiO2 adsorbed with ISQ-(COOH)2 in the nitrogen atmosphere under VL irradiation. We proposed the degradation mechanism of MO on TiO2 adsorbed with ISQ-(COOH)2 or ISQ-COOHCOOBu.
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U2 - 10.1016/j.jphotochem.2021.113543
DO - 10.1016/j.jphotochem.2021.113543
M3 - Article
AN - SCOPUS:85114912560
SN - 1010-6030
VL - 421
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
M1 - 113543
ER -