采用原子力显微镜(AFM)研究了TiO_2颗粒在不同介质条件下的聚集行为.结果表明,TiO_2的聚集存在两重行为即大颗粒间的弱聚集和晶粒间的强聚集.超声条件下,水中可以打开大颗粒间的弱聚集而不能打开强聚集,但是在同样条件下通过选择含有单供电子的分子如丁酮或三乙胺为介质,可以打开强聚集得到单个晶粒.结合介质的分子结构,提出了TiO_2的聚集源于表面不饱和配位原子的氢键及配位的作用机理.对理解底端向上策略组装纳米晶粒和避免纳米颗粒在应用中存在的聚集问题有重要意义.
The aggregation behavior of titanium dioxide(TiO_2)particles in different medium is investigated with atomic force microscopy(AFM).The results demonstrate that two aggregation manners of TiO_2,week interaction of large paticles and strong interaction of nanocrystal are observed.Under ultrasonic treament combined with different solvent,the weak interaction between larger units can be unfolded except the strong interaction of nanocrystals.On the same condition,the single TiO_2 nanocrystal is achieved in the solvent such as butanone and triethylamine with single donor atom.A skech map for the interaction of TiO_2 suggests that the aggregation results from the presence of unsatureated atoms on the surface of TiO_2 nanoparticles,which can act with other molecule or surface through hydrogen and coordination bond.These findings will help us in understanding the organization of nanocrystal in bottom-up strategy and controlling the aggregation of nanoparticles in application.
参考文献
| [1] | Gr(a)tzel M .Photoelectrochemical cells[J].Nature,2001,414:338. |
| [2] | Linsebigler A L;Lu G Q;Yates J T .Photocatalysis on TiO_2 surfaces:Principles,mechanisms,and selected results[J].Chemical Reviews,1995,95:735. |
| [3] | Khan S U M;Al-Shahry M;Ingler Jr W B .Efficient photochemical water splitting by a chemically modified n-TiO_2[J].Science,2002,297:2243. |
| [4] | Anpo M;Shima T;Kodama S et al.Photocatalytic hyarogenation of propyne with water on small-particle titania:Size quantization effects and reaction intermediates[J].Journal of Physical Chemistry,1987,91:4305. |
| [5] | Zhang HZ.;Gilbert B.;Huang F.;Banfield JF. .Water-driven structure transformation in nanoparticles at room temperature[J].Nature,2003(6952):1025-1029. |
| [6] | Huang F;Gilbert B;Zhang H Z et al.Reversible,surfacecontrolled structure transformation in nanoparticles inducedby an aggregation state[J].Physical Review Letters,2004,92:155501. |
| [7] | 徐建华,戴维林,李静霞,李闻,曹勇,范康年.银修饰的二氧化钛多孔微管的制备、表征及光催化活性[J].化学学报,2007(12):1172-1176. |
| [8] | 孙岚,李静,庄惠芳,赖跃坤,王成林,林昌健.TiO2纳米管阵列的制备、改性及其应用研究进展[J].无机化学学报,2007(11):1841-1850. |
| [9] | Huang F et al.Size-dependent phase transformation kinetics in nanoerystalline ZnS[J].Journal of the American Chemical Society,2005,127:4523. |
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