TY - JOUR
T1 - One-pot synthesis of (anatase/bronze-type)-TiO2/carbon dot polymorphic structures and their photocatalytic activity for H2 generation
AU - Khan, Sovann
AU - Kubota, Yuta
AU - Lei, Wenwei
AU - Suzuki, Norihiro
AU - Nakata, Kazuya
AU - Terashima, Chiaki
AU - Matsushita, Nobuhiro
AU - Fujishima, Akira
AU - Katsumata, Ken ichi
N1 - Funding Information:
This research was financially supported by a Grant-in-Aid for JSPS Fellows ( 18F18337 ) from the Japan Society for the Promotion of Science (JSPS). The authors thank Technical Department, Ookayama Materials Analysis Division, Tokyo Institute of Technology, for performing the FE-TEM observation. S. Khan would like to thank JSPS for supporting his postdoctoral research (standard-P18337).
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - We report the one-pot synthesis of anatase/bronze-type ((A/B)-TiO2) and carbon dots (CDs) via a simple solvothermal method using only TiCl4 and ethylene glycol. Control of the reaction temperature and duration enabled the compositions of pure (B) phase, (A/B)-TiO2/CDs, and (A)-TiO2/CDs to be tuned. A series of experiments on the synthesis conditions was carefully conducted at various temperatures (150–200 °C) for various reaction times (5–36 h). Pure phase (B)-TiO2 was obtained at 150 °C for all reaction times (5 to 36 h). The (B)-phase was transformed to anatase at temperatures from 170 °C for reaction times longer than 12 h. At the same time, CDs were formed from the decomposition of ethylene glycol at temperatures greater than 160 °C and long reaction times (>12 h). The photocatalytic activities of the composite catalysts were evaluated by H2 generation from a water-ethylene glycol mixed solution under UV–visible light. H2 generation rates were observed in this order: (A/B)-TiO2/CDs > (A)-TiO2/CDs > (B)-TiO2 > (A)-TiO2. This high photocatalytic activity for (A/B)-TiO2/CDs is attributed to effective charge-separation and broad-light absorption. The developed method will be important for the facile synthesis of (A/B)-TiO2/CD materials and has more potential than conventional multi-step methods.
AB - We report the one-pot synthesis of anatase/bronze-type ((A/B)-TiO2) and carbon dots (CDs) via a simple solvothermal method using only TiCl4 and ethylene glycol. Control of the reaction temperature and duration enabled the compositions of pure (B) phase, (A/B)-TiO2/CDs, and (A)-TiO2/CDs to be tuned. A series of experiments on the synthesis conditions was carefully conducted at various temperatures (150–200 °C) for various reaction times (5–36 h). Pure phase (B)-TiO2 was obtained at 150 °C for all reaction times (5 to 36 h). The (B)-phase was transformed to anatase at temperatures from 170 °C for reaction times longer than 12 h. At the same time, CDs were formed from the decomposition of ethylene glycol at temperatures greater than 160 °C and long reaction times (>12 h). The photocatalytic activities of the composite catalysts were evaluated by H2 generation from a water-ethylene glycol mixed solution under UV–visible light. H2 generation rates were observed in this order: (A/B)-TiO2/CDs > (A)-TiO2/CDs > (B)-TiO2 > (A)-TiO2. This high photocatalytic activity for (A/B)-TiO2/CDs is attributed to effective charge-separation and broad-light absorption. The developed method will be important for the facile synthesis of (A/B)-TiO2/CD materials and has more potential than conventional multi-step methods.
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U2 - 10.1016/j.apsusc.2020.146650
DO - 10.1016/j.apsusc.2020.146650
M3 - Article
AN - SCOPUS:85084818163
SN - 0169-4332
VL - 526
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 146650
ER -