复合纳米Fe_2O_3/TiO_2的制备、表征及光催化活性

Preparation, Characterization and Photocatalytic Reactivity of Coupled Fe_2O_3/TiO_2 Nanometer Powder

采用将TiO2 加入Fe(OH ) 3 胶体中的方法制得复合的Fe2 O3 /TiO2 纳米粒子 .以光催化降解甲胺磷研究其光催化活性 ,并通过XRD、TEM、DRS等分析方法 ,探讨了影响其光催化活性的原因 .结果表明 ,Fe2 O3 的复合量对Fe2 O3 /TiO2 的活性影响很大 ,当n(Fe)∶n(Ti) <0 .3%时 ,复合物Fe2 O3 /TiO2 的光催化活性大于TiO2 ,最佳的复合量为0 .2 % .当复合量大于 0 .5 %时 ,复合物Fe2 O3 /TiO2 的光催化活性低于TiO2 .锻烧温度及锻烧时间对复合物Fe2 O3 /TiO2 光催化活性均有影响 .用XRD确定掺杂前后TiO2 的晶型均为锐钛矿型 ,当复合量大于 0 .7%时才能看到Fe2 O3 的衍射峰 .TEM照片表明 ,由于复合量小 ,复合前后颗粒直径和晶粒直径基本一致 .反射率光谱图表明 ,在 36 0～ 6 5 0nm范围内复合物Fe2 O3 /TiO2 吸收光的性能比TiO2 好 。

Coupled Fe 2O 3/TiO 2 nanometer powders were prepared by adding TiO 2 in Fe(OH) 3 colloid, the photocatalytic reactivity was characterized by the photocatalytic degradation of methamidophos, and Fe 2O 3/TiO 2 was studied by XRD,TEM and DRS in this paper. It was found that when n (Fe)∶ n (Ti) was less than 0.3%,the photocatalytic reactivity was higher than that of TiO 2, and the best amount of n (Fe)∶ n (Ti) was 0.2%. When n (Fe)∶ n (Ti) was more than 0.5%,the photocatalytic reactivity of Fe 2O 3/TiO 2 was lower than that of TiO 2. The temperature and time of annealing affected the photocatalytic reactivity of Fe 2O 3_TiO 2. The particle grew when the time of annealing increased, so its photocatalytic reactivity decreased. The crystalline of TiO 2 was confirmed to be anatase both before and after being coupled by XRD, when n (Fe)∶ n (Ti) was more than 0.7%, the diffraction of Fe 2O 3 only could be observed. TEM photographs showed that the diameter of particle and crystal of Fe 2O 3/TiO 2 and TiO 2 were about the same. It was shown that the light absorption of Fe 2O 3/TiO 2 in the range of 360～650 nm was improved by DRS, that was to increase the absorption of the visible light.