TY - JOUR

T1 - Regarding the Nature of Charge Carriers Formed by UV or Visible Light Excitation of Carbon-Modified Titanium Dioxide

AU - Arimi, Arsou

AU - Günnemann, Carsten

AU - Curti, Mariano

AU - Bahnemann, Detlef W.

N1 - Funding information: This research was supported by Saint-Petersburg State University via a research Grant ID 32706707. The publication of this article was funded by the Open Access fund of Leibniz Universität Hannover. Acknowledgments: The authors are grateful to Dr. Gerald Dräger for performing the HPLC-MS measurements. A.A. acknowledges the financial support of the Deutscher Akademischer Austauschdienst (DAAD). C.G. acknowledges financial support from the Leibniz Universität Hannover within the program “Wege in die Forschung II”. M.C. is grateful to the DAAD together with the Ministerio de Educación, Cultura, Ciencia y Tecnología (Argentina) for his ALEARG scholarship.

PY - 2019/8

Y1 - 2019/8

N2 - Although titanium dioxide gathers many of the required properties for its application in photocatalytic processes, its lack of activity in the visible range is a major hurdle yet to be overcome. Among different strategies, the post-synthesis modification of TiO 2 powders with organic compounds has already led to commercially available materials, such as KRONOClean 7000. In this work, we apply diffuse reflectance transient absorption spectroscopy on this visible-light active photocatalyst and study the dynamics of the charge carriers alternatively induced by UV or visible light laser irradiation, under inert or reactive atmospheres. Our results can be interpreted by considering the material as TiO 2 sensitized by an organic-based layer, in agreement with previous studies on it, and show that the oxidative power of the material is considerably diminished under visible light irradiation. By complementarily performing continuous visible light irradiation photocatalysis experiments in aerated aqueous suspensions, we show that, although the oxidation of methanol proceeds at a very slow rate, the oxidation of chlorpromazine occurs much faster thanks to its better suited redox potential.

AB - Although titanium dioxide gathers many of the required properties for its application in photocatalytic processes, its lack of activity in the visible range is a major hurdle yet to be overcome. Among different strategies, the post-synthesis modification of TiO 2 powders with organic compounds has already led to commercially available materials, such as KRONOClean 7000. In this work, we apply diffuse reflectance transient absorption spectroscopy on this visible-light active photocatalyst and study the dynamics of the charge carriers alternatively induced by UV or visible light laser irradiation, under inert or reactive atmospheres. Our results can be interpreted by considering the material as TiO 2 sensitized by an organic-based layer, in agreement with previous studies on it, and show that the oxidative power of the material is considerably diminished under visible light irradiation. By complementarily performing continuous visible light irradiation photocatalysis experiments in aerated aqueous suspensions, we show that, although the oxidation of methanol proceeds at a very slow rate, the oxidation of chlorpromazine occurs much faster thanks to its better suited redox potential.

KW - Carbon-based modified TiO

KW - Carbon-doped materials

KW - Chlorpromazine

KW - KRONOClean 7000

KW - Transient absorption spectroscopy

KW - Visible light driven photocatalysis

UR - http://www.scopus.com/inward/record.url?scp=85076152425&partnerID=8YFLogxK

U2 - 10.3390/catal9080697

DO - 10.3390/catal9080697

M3 - Article

VL - 9

JO - CATALYSTS

JF - CATALYSTS

SN - 2073-4344

IS - 8

M1 - 697

ER -