Au纳米粒子大小对Au/TiO_2薄膜光催化活性的影响

Effect of Au Nanoparticle Size on Photocatalysis Performance of Au/TiO_2 Membrane

用混合-超声分散方法制备了3种负载不同粒径Au纳米粒子的T iO2薄膜。利用透射电镜测定Au纳米粒子的粒径,用紫外-可见光谱和测量光电流方法对Au/T iO2薄膜进行表征,以亚甲基蓝降解反应评价Au/T iO2薄膜的光催化活性,讨论Au纳米粒子的大小对Au/T iO2薄膜光催化活性的影响。实验结果表明,与纯的T iO2薄膜相比,负载不同粒径Au纳米粒子的T iO2薄膜的光电流和光催化活性均有不同程度的提高。负载平均粒径约8nm的Au粒子的T iO2薄膜电极具有最大的光电流(光电流为38μA,是纯T iO2薄膜电极的2.2倍)和最高的光催化活性(3h后对亚甲基蓝的降解率达到92%,是纯T iO2薄膜的1.5倍)。

TiO2 membranes loaded with different sizes of Au nanoparticles were prepared by mixing-supersonic dispersion method. Size of Au nanoparticles was measured by TEM. Au/TiO2 membrane was characterized by UV-Vis and photocurrent measurement. Photocatalytic activity of Au/TiO2 membrane was evaluated by degradation of methylene blue under UV radiation, and effect of Au nanoparticles size on photocatalytic activity of Au/TiO2 membrane was discussed. Photocurrent and photocatalytic activities of TiO2 membrane strengthened after loading Au nanoparticles of different sizes on the membrane. When 8 nm Au nanoparticles were loaded on it, photocurrent and photocatalytic activities of Au/TiO2 membrane reached maximum. The former was 38 μA, 2.2 times as that of pure TiO2 membrane. The photo-degradation conversion of methylene blue reached 92% in 3 hours, 1.5 times as that of pure TiO2 membrane.