摘要
以钛酸四丁酯和氯金酸为原料,通过溶胶-凝胶法制备了Au掺杂的纳米TiO2光催化剂粉体,并用XRD、BET、XPS和固体紫外可见吸收光谱等技术对其晶相结构、比表面积、表面组成及紫外可见光响应范围进行了表征,对其光催化降解非离子表面活性剂壬基酚聚氧乙烯醚(NPE-10)的活性进行了考察.结果表明,掺杂的Au在纳米TiO2粉体材料中可能以两种形态存在,即以Au3+离子形式替代Ti4+进入TiO2晶格和以Au原子态形式暴露于粉体表面.前者使TiO2在480～650nm出现了更强的光吸收;后者中处于表面原子态的Au又会成为光生电子的受体,有效地避免了光生电子空穴对的复合.通过对掺杂量及处理温度的优化,在nAu3+/nTi4+=0.005,500℃煅烧的条件下可以制得具有较高的光催化活性的Au/TiO2粉体.对NPE-10的光催化氧化试验显示,日光照射4h后降解效率可以达到91.8%;而用未改性的纳米TiO2,在同样条件下,NPE-10的光催化降解效率仅能达到50.2%,商品DegussaP-25也只能达到66%.
The Au modified nanosized titanium oxide （TiO2） powders were prepared by sol-gel route at ambient temperature using Ti（OC4H9）4 and HAuCl4 as raw materials. The as-prepared samples were analyzed by XRD, BET, XPS and UV-Visible absorption spectra technique. Photodegration for non-ionic surfactant nonylphenyl poly（oxyethylene） ethers （NPE-10） was carried out in air-equilibrated Au/TiO2 suspensions. The results suggested that the conformation of Au in the TiO2 composite was largely dependent on the concentration of HAuCl4 during the preparation and the Au/TiO2 heat-treated temperature. The doped Au may take the place of Ti^4＋ in the lattices of TiO2 as Au^3＋ or exist at the surface of TiO2 particles as atoms. The former may contribute to light adsorption range from 480 to 650 nm, the later may become the acceptor of photoinduced e^- leading to a decrease of e^-/h^＋ recombination. The preparation parameters were optimized by means of NPE-10 degradation. The optimized catalyst was obtained at Au/Ti molar ratio of 0.005 and calcined at 500℃. The degradation rate of NPE-10 could be up to 91.8% after irradiated 4, h in sunlight compared to 66% for the rate of TiO2-P-25 and 50.2% for the rate of undoped TiO2.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2006年第8期953-957,共5页
Acta Physico-Chimica Sinica
基金
山西省国际合作项目(051012)资助
作者简介
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