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

被引：96

作者：

Lim, Jonghun ^{[1
]}

Monllor-Satoca, Damian ^{[1
]}

Jang, Jum Suk ^{[1
]}

Lee, Seockheon ^{[2
]}

Choi, Wonyong ^{[1
]}

机构：

[1] Pohang Univ Sci & Technol POSTECH, Sch Environm Sci & Engn, Pohang 790784, South Korea

[2] Korea Inst Sci & Technol, Ctr Water Resources Cycle Res, Seoul 136791, South Korea

来源：

APPLIED CATALYSIS B-ENVIRONMENTAL | 2014年 / 152卷

关键词：

Visible light photocatalyst; Titanium dioxide; Surface-complex charge-transfer; Impurity doping; Degradation of water pollutants; DYE-SENSITIZED TIO2; ANATASE TIO2; SOLAR-CELLS; HYDROGEN; METAL; NANOPARTICLES; POLLUTANTS; ELECTRODES; CONVERSION; INSIGHTS;

D O I：

10.1016/j.apcatb.2014.01.026

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

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 (lambda>420 nm). 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. (c) 2014 Elsevier B.V. All rights reserved.

引用

页码：233 / 240

页数：8

共 45 条

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