Mg-Al layered double hydroxides with carbonate anions (Mg-Al-CO_3-LDHs) were dispersed into a mixed solution of zinc salt and urea. Upon heating, the hydroxide ions released by the urea hydrolysis promoted the precipitation of zinc ions in the solution, and ZnO/Mg-Al mixed oxides were obtained after washing, drying and calcining. The ZnO/Mg-Al mixed oxides were restructured by soaking in Na_2CO_3 solution and the restructured ZnO/Mg-Al mixed oxides (re-ZnO/LDHs)were obtained after subsequent calcination. The nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), nitrogen adsorption-desorption, and Fourier transform infrared spectra (FTIR). The removal efficiencies and the photocatalytic activities of the nanocomposites were investigated by the degradation of acid red G aqueous solution. After the reduction treatment by Na_2CO_3, the grain size of the ZnO decreased and the shape of the Mg-Al mixed oxides in re-ZnO/ LDHs changed into the sheet-like structure. The removal efficiencies of them increased apparently and the re-ZnO/LDHs with a mass ratio of 2:1 had a better photocatalytic activity.%将镁铝层状双氢氧化物分散在锌盐与尿素的混合液中,加热使尿素水解、锌离子沉淀,经洗涤、干燥、煅烧,再用碳酸钠溶液浸渍、煅烧,得到还原后的氧化锌/镁铝复合氧化物.用X-射线衍射(XRD)、透射电子显微镜(TEM)、氮等温吸附和傅里叶红外光谱(FTIR)等方法对所制备的氧化锌/镁铝复合氧化物的结构和性能进行了表征.以酸性红G为模型污染物评价了其去除效率及光催化活性.碳酸钠还原处理过的氧化锌/镁铝复合氧化物结构发生了改变,氧化锌的晶粒变小,复合氧化物变成了片状结构,其对酸性红G的去除效率也明显提高,质量比为2∶1的氧化锌,镁铝复合物经还原后表现出了良好的光催化活性.
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