Materials Express
2158-5849/2017/7/509/007 Copyright © 2017 by American Scientific Publishers All rights reserved. doi:10.1166/mex.2017.1398 Printed in the United States of America www.aspbs.com/mex
A safe and efficient approach to fabricate black carbon-doped rutile titania by substitution of oxygen at carbon sites in titanium carbide film
Sujun Guan1,LiangHao2, Hiroyuki Yoshida3, Yun Lu4, and Xinwei Zhao1,∗ 1Department of Physics, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan 2College of Mechanical Engineering, Tianjin University of Science and Technology, No. 1038, Dagu Nanlu, Hexi District, Tianjin, 300222, China 3Chiba Industrial Technology Research Institute, 6-13-1, Tendai, Inage-ku, Chiba, 263-0016, Japan 4Department of Mechanical Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan Article
ABSTRACT IP: 192.168.39.151 On: Thu, 30 Sep 2021 05:52:08 Black carbon-doped rutile titania (C-dopedCopyright: TiO American) have been Scientific successfully Publishers fabricated by substitution of oxygen (O) Delivered2 by Ingenta at carbon (C) sites in titanium carbide (TiC), via annealing in carbon powder to control oxygen pressure around
TiC film. Compared with that of substitution of C at O sites in TiO2, C-doped TiO2 fabricated by substitution of O at C sites in TiC fundamentally increase the visible-light absorption and enhances photocatalytic activity.
X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results reveal that rutile TiO2 forms on TiC. The increased visible-light absorption and the decreased recombination between electron and hole are
demonstrated by ultraviolet-visible (UV-vis) absorption and photoluminescence (PL). Black C-doped TiO2/TiC films show strong visible-light absorption, and C-doped TiO2 grow from TiC could form the heterojunction to promote the separation of electron–hole pairs.
Keywords: Titanium Carbide, Rutile TiO2, Controlled Oxygen Pressure, Visible-Light, Photocatalysis.
1. INTRODUCTION narrowed-band-gap semiconductors. 6–8 Among doped-
For a desirable way to solve energy and environmental TiO2, C-doped TiO2 has been successively proven to nar- issues, the inexpensive catalyst with visible-light activ- row the band-gap. 9–12 As we know, compared with the ity is strongly required, that directly harvest energy from substitution of C at O sites in TiO , the substitution of 2 solar light. 1 2 Especially, the widely used photocatal- O at C sites in TiC could be more feasible and effi- ysis is TiO2, because of its superior stability, low-cost cient. Also, transition-metal carbides, especially, TiC has 3 4 and photosensitivity. However, the photoreaction effi- attracted much interest because of its superior chemical ciency of TiO2 is severely impeded by its wide band 4 5 stability. Moreover, TiC could be used as a catalyst sup- gap and fast electron–hole recombination. To eliminate port to enhance the catalytic activity. 8 13 Recently, some the two drawbacks, many researches have been devoted researches of oxidation of TiC, focusing on TiC nanopar- to increasing the visible-light absorption and suppress- ticle and oxidation in air to form anatase TiO2, have been ing the electron–hole recombination, mainly by narrowing 13–16 the band gap, optimizing morphology and combining with reported to enhance the photocatalytic activity. How- ever, how to control the formed TiO2 on TiC to be rutile, ∗Author to whom correspondence should be addressed. without sacrificing but further enhancing the visible-light Email: [email protected] photocatalytic activity, is still very difficult.
Mater. Express, Vol. 7, No. 6, 2017 509 Materials Express A safe and efficient approach to fabricate black carbon-doped rutile titania Guan et al.
Herein, it was aimed in black C-doped TiO2/TiC films TiO rutile TiC Al O fabricated by substitution of O at C sites in TiC via anneal- 2 2 3 TiC-carbon ing in carbon powder to control oxygen pressure around TiC film, to increase the visible-light absorption and sup- press the electron–hole recombination. TiC-air ) . u .
2. EXPERIMENTAL DETAILS a (
y t
2.1. Fabrication of Photocatalysts i TiC s