纳米复合材料Ag/MxOy-TiO2(MxOy=ZnO、Al2O3和Fe2O3)的制备及其微波辅助光催化降解甲基橙

采用溶胶-凝胶-程序升温溶剂热一步法，利用表面活性剂EO₂₀PO₇₀EO₂₀(P123)作为模板剂，分别制备了三元纳米复合材料Ag/ZnO-TiO₂、Ag/Al₂O₃-TiO₂和Ag/Fe₂O₃-TiO₂。通过XRD、氮气吸附-脱附测定、TEM以及扫描电子显微镜配合X-射线能量色散谱仪(SEM-EDS)等对合成的3种催化剂进行了对比表征分析。结果表明，复合材料Ag/M_xO_y-TiO₂中Ag以单质形式存在并较好地分布在M_xO_y-TiO₂表面上。所合成产物颗粒尺寸较小(约10 nm左右)，形貌较好。其中，Ag/ZnO-TiO₂的比表面积与Ag/Al₂O₃-TiO₂十分相近，略大于Ag/Fe₂O₃-TiO₂。光催化活性研究中，以甲基橙为模型分子且辅以微波场作用。结果显示，上述三元复合材料的活性均明显高于未掺杂银的二元复合材料，其中Ag/ZnO-TiO₂的光催化活性最好，在90 min内对甲基橙的降解率高达86%。

Ag/MxOy-TiO2(MxOy=ZnO, Al2O3 and Fe2O3): Preparation and Microwave-assised Photocatalytic Degradation of Methyl Orange

The three-component nanocomposites, Ag/ZnO-TiO₂, Ag/Al₂O₃-TiO₂ and Ag/Fe₂O₃-TiO₂, were developed through a sol-gel-temperature solvothermal process in the presence of surfactant EO₂₀PO₇₀EO₂₀(P123). The phase composition, structures and morphologies of three-component nanocomposites were well-characterized via XRD, TEM, N₂ adsorption-desorption and SEM attached X-ray energy dispersive spectroscopy (SEM-EDS). The results indicated that silver species existing in the nano-composite was metallic Ag⁰ and well distributed on the surface of M_xO_y-TiO₂. The particle sizes of the three catalysts were very small (about 10 nm) and the morphologies were better. The BET surface area of Ag/ZnO-TiO₂ was very close to Ag/Al₂O₃-TiO₂ and a little larger than that of Ag/Fe₂O₃-TiO₂. The photocatalytic activities of the as-prepared materials were studied by the microwave assisted photodegradation of methyl orange. The results indicated that the photocatalytic activities of the three-component nanocomposites were higher than those of two-component nanocomposites without silver doping. The photocatalytic activity of Ag/ZnO-TiO₂ was the best with a methyl orange degradation ratio of 86% within 90 min.