Fabrication and enhanced visible-light photocatalytic activity of carbon self-doped TiO2 sheets with exposed {001} facets
Fabrication and enhanced visible-light photocatalytic activity of carbon self-doped TiO2 sheets with exposed {001} facets
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DOI：
10.1039/c0jm02217a
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发表时间：
2011-01
影响因子：
--
通讯作者：
Jiaguo Yu;Gaopeng Dai;Quanjun Xiang;M. Jaroniec
中科院分区：
文献类型：
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作者：
Jiaguo Yu;Gaopeng Dai;Quanjun Xiang;M. Jaroniec
通过碳化钛(TiC)在硝酸-氢氟酸混合水溶液中的水热处理，合成了{001}晶面暴露的新型碳自掺杂二氧化钛薄膜(CTS)。采用TiC作为前驱体和C源，将TiC自掺杂到锐钛矿片的晶格中。在可见光(λ>；420 nm)的照射下，考察了所得材料作为光催化剂降解水溶液中亚甲基蓝(MB)的性能。这些材料在整个可见光区域表现出增强的吸收，并且在吸收边有明显的红移。第一性原理密度泛函理论(DFT)计算进一步证实了上述红移现象，并证实了具有暴露的{001}面的C掺杂二氧化钛薄膜的禁带宽度显著减小。CTS的光催化研究表明，由于暴露的{001}面的存在，这些薄膜表现出比C掺杂的纳米二氧化钛更高的光催化活性。此外，与传统的纳米粉末光催化剂相比，通过过滤或沉淀法将光催化反应后的CTS从浆料中分离出来并重复使用更容易。
Novel carbon self-doped TiO2 sheets (CTS) with exposed {001} facets were synthesized by hydrothermal treatment of titanium carbide (TiC) in a HNO3-HF mixed aqueous solution. In this synthesis TiC was used as a precursor of TiO2 and a source of C, which was self-doped into the lattice of anatase sheets. The resulting CTS materials were examined as photocatalysts for degradation of methylene blue (MB) in aqueous solutions under visible light irradiation (λ > 420 nm). These materials exhibited an enhanced absorption in the whole visible-light region and an obvious red shift at the absorption edges. The first-principle density functional theory (DFT) calculations provided a further confirmation for the aforementioned red shift and for noticeable reduction of the band gap of C-doped TiO2 sheets with exposed {001} facets. The photocatalytic studies of CTS showed that these sheets exhibited much higher photocatalytic activity than that of the C-doped TiO2 nanoparticles due to the presence of exposed {001} facets. In addition, separation of CTS after photocatalytic reaction from slurry by filtration or sedimentation and their reuse is easier in comparison to conventional nanosized powder photocatalysts.