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化学学报
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化学学报 ›› 2006, Vol. 64 ›› Issue (6): 453-457.    下一篇

研究通讯

CO2在纳米SiO2/TiO2悬浮体系中的光催化还原

刘亚琴，徐耀，李志杰，张秀萍，吴东，孙予罕*   

  1. (1中国科学院山西煤炭化学研究所煤转化国家重点实验室 太原 030001)
    (2中国科学院研究生院 北京 100039)
  • 投稿日期:2005-09-07 修回日期:2005-12-28 发布日期:2006-03-28
  • 通讯作者: 孙予罕

Photocatalytic Reduction of CO2 in the Suspension System of Nano-SiO2/TiO2

LIU Ya-Qin, XU Yao, LI Zhi-Jie, ZHANG Xiu-Ping, WU Dong, SUN Yu-Han*   

  1. (1 State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001)
    (2 Graduate School of the Chinese Academy of Sciences, Beijing 100039)
  • Received:2005-09-07 Revised:2005-12-28 Published:2006-03-28
  • Contact: SUN Yu-Han

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用水热法合成了氧化硅改性的具有高比表面积、高催化活性的锐钛型二氧化钛, 并在其悬浮体系中将CO2光催化还原合成甲醇. 采用XRD, TEM, 物理吸附, UV-Vis吸收光谱和FTIR等表征手段对催化剂结构特征进行了研究. 结果表明: 添加氧化硅后, 氧化硅和二氧化钛之间形成Si—O—Ti键, 抑制了TiO2晶粒生长, 提高了锐钛型TiO2的比表面积, 且随着含硅量的增加, SiO2/TiO2的UV吸收逐步蓝移, 禁带宽度增加. 还原反应结果表明: SiO2/TiO2具有光催化还原活性, 且随着含硅量的增加先增加后减小, 当SiO2质量分数为3.5%时, SiO2/TiO2复合催化剂反应活性最强, 5 h内甲醇产量可达到21.0 mg/L, 并有少量甲醛生成.

关键词: TiO2, 水热法, 光催化还原, CO2

Silica-modified anatase titanium dioxide was prepared by the hydrothermal method, with large surface area and high photocatalytic activity. Photocatalytic reduction of CO2 was carried out to synthesize methanol in the aqueous suspension system of nano TiO2. The catalyst was characterized by XRD, TEM, BET, UV-Vis diffuse reflectance and FTIR spectroscopy methods. The results showed formation of Si—O—Ti bond on the silica-modified titanium dioxide surfaces. The addition of silica to TiO2 could restrain the growth of TiO2 crystalline grain and enhance the surface area. The silica-modified titanium dioxides had significant blue shift in UV absorption compared to the bulk TiO2. The reductive results of CO2 showed that the nano SiO2/TiO2 already obtained obvious photocatalytic reduction activity. When the addition of silica to TiO2 reached w(silica)＝3.5%, it gave the highest activity, producing 21.0 mg/L of methanol during 5 h reaction under the irradiation of 365 nm UV light.

Key words: titanium dioxide, hydrothermal, photocatalytic reduction, carbon dioxide