Photocatalytic decolourization of dyes on NiO–ZnO nano-composites
Photocatalytic decolourization of dyes on NiO–ZnO nano-composites
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DOI：
10.1039/b817396f
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发表时间：
2009-05
影响因子：
3.1
通讯作者：
A. Hameed;T. Montini;V. Gombac;P. Fornasiero
中科院分区：
文献类型：
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作者：
A. Hameed;T. Montini;V. Gombac;P. Fornasiero
以氢氧化钾（KOH）、碳酸钠（Na_2CO_3）和草酸（H_2C_2O_4）为沉淀剂，通过共沉淀/共凝胶形成技术合成了NiO-ZnO纳米复合光催化剂。 X 射线衍射 (XRD) 分析用于确定微晶尺寸和相纯度，而 BET 表面积则通过氮物理吸附分析来估计。 NiO-ZnO 纳米复合材料的光催化活性通过两种结构不同的染料（甲基橙和亚甲基蓝）的光脱色进行评估，与复合材料成分的微晶尺寸的变化相关。所有三种合成的纳米复合材料均表现出明显的染料脱色活性。由KOH衍生的NiO-ZnO纳米复合材料对两种染料的脱色表现出最大的活性，并且发现亚甲基蓝的脱色率与Degussa P-25 TiO_2的脱色率相当。最后，将具有相对较大晶粒尺寸的最活跃的 NiO-ZnO 复合材料的活性与纯组分及其物理混合物进行比较，这些混合物是通过相同的合成路线、与纳米复合材料相同的摩尔比合成的。
NiO–ZnO nanocomposite photocatalysts were synthesized by co-precipitation/co-gel formation techniques using potassium hydroxide (KOH), sodium carbonate (Na_2CO_3) and oxalic acid (H_2C_2O_4) as precipitating agents. X-Ray diffraction (XRD) analysis was employed for the determination of crystallite size and phase purity, while BET surface areas were estimated by nitrogen physisorption analysis. The photocatalytic activities of the NiO–ZnO nanocomposites, evaluated using the photo-decolourization of two structurally different dyes, methyl orange and methylene blue, were correlated with the variation in the crystallite size of the constituents of the composites. All the three synthesized nanocomposites showed appreciable activity for the decolourization of dyes. NiO–ZnO nanocomposite derived by KOH exhibited maximum activity for the decolourization of both the dyes and the decolourization rate of methylene blue was found to be comparable with that of Degussa P-25 TiO_2. Finally, the activity of the most active NiO–ZnO composite with relatively large crystallite sizes was compared with the pure components and their physical mixture, synthesized by the identical synthetic route, in the same molar ratio as that of nanocomposite.