Visible light photocatalysis of fullerol-complexed TiO2 enhanced by Nb doping

Jonghun Lim; Damián Monllor-Satoca; Jum Suk Jang; Seockheon Lee; Wonyong Choi

doi:10.1016/j.apcatb.2014.01.026

Visible light photocatalysis of fullerol-complexed TiO₂ enhanced by Nb doping

Jonghun Lim
, Damián Monllor-Satoca
, Jum Suk Jang
, Seockheon Lee
, Wonyong Choi^*

^*Corresponding author for this work

Environmental Biotechnology

Pohang University of Science and Technology
Korea Institute of Science and Technology

Research output: Contribution to journal › Journal article › peer-review

99 Scopus citations

Abstract

Visible light photocatalysis by TiO₂ nanoparticles modified with both fullerol complexation and Nb-doping (fullerol/Nb-TiO₂) demonstrated an enhanced performance. Nb-doped TiO₂ (Nb-TiO₂) was firstly prepared by a conventional sol-gel method, and subsequently fullerol was adsorbed on the surface of Nb-TiO₂. The physicochemical and optical properties of as-prepared fullerol/Nb-TiO₂ were analyzed by various spectroscopic methods (TEM, EELS, XPS, and DRS). The adsorption of fullerol on Nb-TiO₂ surface increased the visible light absorption through a surface-complex charge-transfer (SCCT) mechanism. Nb-doping enhanced the charge transport and induced the Ti cation vacancies that retarded the recombination of photo-generated charge pairs by trapping the electrons injected from the HOMO level of fullerol. Due to the advantage of simultaneous modification of fullerol and Nb-doping, the visible light photoactivity of fullerol/Nb-TiO₂ was more enhanced than either Nb-TiO₂ or fullerol/TiO₂. The photocatalytic activities of fullerol/Nb-TiO₂ for the reduction of chromate (Cr^VI), the oxidation of iodide, and the degradation of 4-chlorophenol were all higher than bare TiO₂ and singly modified TiO₂ (i.e., Nb-TiO₂ and fullerol/TiO₂) under visible light (λ>420nm). A similar result was also confirmed for their photoelectrochemical behavior: the electrode made of fullerol/Nb-TiO₂ exhibited an enhanced photocurrent under visible light. On the other hand, the decay of open-circuit potential of the fullerol/Nb-TiO₂ electrode after turning off the visible light was markedly slower than either that of Nb-TiO₂ or fullerol/TiO₂, which implies the retarded recombination of photo-generated charge pairs on fullerol/Nb-TiO₂. In addition, the electrochemical impedance spectroscopic (EIS) data supported that the charge transfer resistance is lower with the fullerol/Nb-TiO₂ than either Nb-TiO₂ or fullerol/TiO₂. This specific combination of the bulk (Nb-doping) and surface (fullerol complexation) modifications of titanium dioxide might be extended to other cases of bulk+surface combined modifications.

Original language	English
Pages (from-to)	233-240
Number of pages	8
Journal	Applied Catalysis B: Environmental
Volume	152-153
Issue number	1
DOIs	https://doi.org/10.1016/j.apcatb.2014.01.026
State	Published - 2014.06.25

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 6 Clean Water and Sanitation

Keywords

Degradation of water pollutants
Impurity doping
Surface-complex charge-transfer
Titanium dioxide
Visible light photocatalyst

Access to Document

10.1016/j.apcatb.2014.01.026

Cite this

@article{df96014314864958a101a6e3b8c875fe,

title = "Visible light photocatalysis of fullerol-complexed TiO2 enhanced by Nb doping",

abstract = "Visible light photocatalysis by TiO2 nanoparticles modified with both fullerol complexation and Nb-doping (fullerol/Nb-TiO2) demonstrated an enhanced performance. Nb-doped TiO2 (Nb-TiO2) was firstly prepared by a conventional sol-gel method, and subsequently fullerol was adsorbed on the surface of Nb-TiO2. The physicochemical and optical properties of as-prepared fullerol/Nb-TiO2 were analyzed by various spectroscopic methods (TEM, EELS, XPS, and DRS). The adsorption of fullerol on Nb-TiO2 surface increased the visible light absorption through a surface-complex charge-transfer (SCCT) mechanism. Nb-doping enhanced the charge transport and induced the Ti cation vacancies that retarded the recombination of photo-generated charge pairs by trapping the electrons injected from the HOMO level of fullerol. Due to the advantage of simultaneous modification of fullerol and Nb-doping, the visible light photoactivity of fullerol/Nb-TiO2 was more enhanced than either Nb-TiO2 or fullerol/TiO2. The photocatalytic activities of fullerol/Nb-TiO2 for the reduction of chromate (CrVI), the oxidation of iodide, and the degradation of 4-chlorophenol were all higher than bare TiO2 and singly modified TiO2 (i.e., Nb-TiO2 and fullerol/TiO2) under visible light (λ>420nm). A similar result was also confirmed for their photoelectrochemical behavior: the electrode made of fullerol/Nb-TiO2 exhibited an enhanced photocurrent under visible light. On the other hand, the decay of open-circuit potential of the fullerol/Nb-TiO2 electrode after turning off the visible light was markedly slower than either that of Nb-TiO2 or fullerol/TiO2, which implies the retarded recombination of photo-generated charge pairs on fullerol/Nb-TiO2. In addition, the electrochemical impedance spectroscopic (EIS) data supported that the charge transfer resistance is lower with the fullerol/Nb-TiO2 than either Nb-TiO2 or fullerol/TiO2. This specific combination of the bulk (Nb-doping) and surface (fullerol complexation) modifications of titanium dioxide might be extended to other cases of bulk+surface combined modifications.",

keywords = "Degradation of water pollutants, Impurity doping, Surface-complex charge-transfer, Titanium dioxide, Visible light photocatalyst",

author = "Jonghun Lim and Dami{\'a}n Monllor-Satoca and Jang, \{Jum Suk\} and Seockheon Lee and Wonyong Choi",

year = "2014",

month = jun,

day = "25",

doi = "10.1016/j.apcatb.2014.01.026",

language = "English",

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pages = "233--240",

journal = "Applied Catalysis B: Environmental",

issn = "0926-3373",

number = "1",

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TY - JOUR

T1 - Visible light photocatalysis of fullerol-complexed TiO2 enhanced by Nb doping

AU - Lim, Jonghun

AU - Monllor-Satoca, Damián

AU - Jang, Jum Suk

AU - Lee, Seockheon

AU - Choi, Wonyong

PY - 2014/6/25

Y1 - 2014/6/25

N2 - Visible light photocatalysis by TiO2 nanoparticles modified with both fullerol complexation and Nb-doping (fullerol/Nb-TiO2) demonstrated an enhanced performance. Nb-doped TiO2 (Nb-TiO2) was firstly prepared by a conventional sol-gel method, and subsequently fullerol was adsorbed on the surface of Nb-TiO2. The physicochemical and optical properties of as-prepared fullerol/Nb-TiO2 were analyzed by various spectroscopic methods (TEM, EELS, XPS, and DRS). The adsorption of fullerol on Nb-TiO2 surface increased the visible light absorption through a surface-complex charge-transfer (SCCT) mechanism. Nb-doping enhanced the charge transport and induced the Ti cation vacancies that retarded the recombination of photo-generated charge pairs by trapping the electrons injected from the HOMO level of fullerol. Due to the advantage of simultaneous modification of fullerol and Nb-doping, the visible light photoactivity of fullerol/Nb-TiO2 was more enhanced than either Nb-TiO2 or fullerol/TiO2. The photocatalytic activities of fullerol/Nb-TiO2 for the reduction of chromate (CrVI), the oxidation of iodide, and the degradation of 4-chlorophenol were all higher than bare TiO2 and singly modified TiO2 (i.e., Nb-TiO2 and fullerol/TiO2) under visible light (λ>420nm). A similar result was also confirmed for their photoelectrochemical behavior: the electrode made of fullerol/Nb-TiO2 exhibited an enhanced photocurrent under visible light. On the other hand, the decay of open-circuit potential of the fullerol/Nb-TiO2 electrode after turning off the visible light was markedly slower than either that of Nb-TiO2 or fullerol/TiO2, which implies the retarded recombination of photo-generated charge pairs on fullerol/Nb-TiO2. In addition, the electrochemical impedance spectroscopic (EIS) data supported that the charge transfer resistance is lower with the fullerol/Nb-TiO2 than either Nb-TiO2 or fullerol/TiO2. This specific combination of the bulk (Nb-doping) and surface (fullerol complexation) modifications of titanium dioxide might be extended to other cases of bulk+surface combined modifications.

AB - Visible light photocatalysis by TiO2 nanoparticles modified with both fullerol complexation and Nb-doping (fullerol/Nb-TiO2) demonstrated an enhanced performance. Nb-doped TiO2 (Nb-TiO2) was firstly prepared by a conventional sol-gel method, and subsequently fullerol was adsorbed on the surface of Nb-TiO2. The physicochemical and optical properties of as-prepared fullerol/Nb-TiO2 were analyzed by various spectroscopic methods (TEM, EELS, XPS, and DRS). The adsorption of fullerol on Nb-TiO2 surface increased the visible light absorption through a surface-complex charge-transfer (SCCT) mechanism. Nb-doping enhanced the charge transport and induced the Ti cation vacancies that retarded the recombination of photo-generated charge pairs by trapping the electrons injected from the HOMO level of fullerol. Due to the advantage of simultaneous modification of fullerol and Nb-doping, the visible light photoactivity of fullerol/Nb-TiO2 was more enhanced than either Nb-TiO2 or fullerol/TiO2. The photocatalytic activities of fullerol/Nb-TiO2 for the reduction of chromate (CrVI), the oxidation of iodide, and the degradation of 4-chlorophenol were all higher than bare TiO2 and singly modified TiO2 (i.e., Nb-TiO2 and fullerol/TiO2) under visible light (λ>420nm). A similar result was also confirmed for their photoelectrochemical behavior: the electrode made of fullerol/Nb-TiO2 exhibited an enhanced photocurrent under visible light. On the other hand, the decay of open-circuit potential of the fullerol/Nb-TiO2 electrode after turning off the visible light was markedly slower than either that of Nb-TiO2 or fullerol/TiO2, which implies the retarded recombination of photo-generated charge pairs on fullerol/Nb-TiO2. In addition, the electrochemical impedance spectroscopic (EIS) data supported that the charge transfer resistance is lower with the fullerol/Nb-TiO2 than either Nb-TiO2 or fullerol/TiO2. This specific combination of the bulk (Nb-doping) and surface (fullerol complexation) modifications of titanium dioxide might be extended to other cases of bulk+surface combined modifications.

KW - Degradation of water pollutants

KW - Impurity doping

KW - Surface-complex charge-transfer

KW - Titanium dioxide

KW - Visible light photocatalyst

UR - https://www.scopus.com/pages/publications/84894027712

U2 - 10.1016/j.apcatb.2014.01.026

DO - 10.1016/j.apcatb.2014.01.026

M3 - Journal article

AN - SCOPUS:84894027712

SN - 0926-3373

VL - 152-153

SP - 233

EP - 240

JO - Applied Catalysis B: Environmental

JF - Applied Catalysis B: Environmental

IS - 1

ER -