| 胱氨酸改性TiO2可见光下催化活性及催化机理 |
| Mechanism and Photocatalytic Activity of Cystine-Modified TiO2 with Visible-Light Response |
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| 摘要: 以胱氨酸为掺杂剂，采用溶胶-凝胶法制备了胱氨酸改性的TiO2可见光催化剂，并对其进行了TG-DTA、XRD、表面光电压光谱(SPS)及XPS表征。XRD结果表明，胱氨酸有效抑制了TiO2晶粒的生长，提高了锐钛矿向金红石相的转变温度。SPS分析结果显示，改性TiO2光催化剂可见光吸收增强，吸收带边明显红移，且胱氨酸用量为4.2%的样品光伏响应强度最大。XPS分析结果表明，胱氨酸改性TiO2样品表面的羟基含量明显增加，且O2p价带的VMB(价带最大值)值为2.3 eV，小于非改性TiO2。以罗丹明B为模型污染物，考察了胱氨酸掺杂量与焙烧温度对改性TiO2在可见光下催化性能。结果表明，胱氨酸掺杂量(相对TiO2)为4.2%、350 ℃焙烧的催化剂催化活性最好。波长为380~630 nm、470~800 nm的光辐射120 min后，罗丹明B的降解率分别达到91.02%、78.44%。 |
| 关键词: 光催化 TiO2 胱氨酸 罗丹明B |
| 基金项目: |
| Abstract: TiO2 nano-particles modified by cystine were prepared through a sol-gel procedure using cystine as the doping species and characterized by TG-DTA, XRD, Surface Photo-voltage Spectroscopy (SPS) and XPS. The XRD results show that cystine added in TiO2 preparation could effectively restrain the growth of crystallite and enhance the temperature of phase transformation. SPS results indicate that the light absorbance edge of cystine modified TiO2 nano-particles is obviously red-shifted to visible-light and the strongest signal intensity of photovoltaic response is given by modified TiO2 nano-particle with 4.2% cystine. XPS analysis implies that the content of surface hydroxyl increases significantly and VBM(Valance Bond Maximum) of O2p is 2.3 eV. The effects of calcination temperature and cystine content on the visible-light photocatalytic performance of modifed TiO2 for degrading RhB were investigated. The modified TiO2 calcined at 350℃with 4.2% cystine content exhibits the best photocatalytic performance. When the irradiation wavelengths are 380~630 nm and 470~800 nm, the removal rate for RhB could achieve 91.02% and 78.44%, respectively. |
| Keywords: photocatalytic TiO2 cystine rhodamine B |
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| 于秀娟,程修文.胱氨酸改性TiO2可见光下催化活性及催化机理[J].无机化学学报,2010,26(12):2150-2154. |
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