一步水热合成ZnO/水热炭复合材料及其性能表征

One-step hydrothermal synthesis and characterization of the ZnO/hydrothermal carbon composite material

为了利用林业剩余物水热炭作光催化剂载体,以(CH_3COO)_2Zn·2H_2O和氨水为起始物,以综纤维素基水热炭为基体,采用一步水热合成法制备ZnO/水热炭复合材料。采用X射线衍射仪、扫描电子显微镜对复合材料的晶相结构、表观形貌等进行表征,并以亚甲基蓝为模型污染物测试了复合材料的光催化性能。研究结果表明:在实验条件下可以制备出ZnO/水热炭复合材料,材料中ZnO为六方纤锌矿结构,随水热炭添加量增加,ZnO尺寸有明显的减小,但当水热炭达到24.6%时,ZnO由一维取向的棒状转而呈现片状。光催化性能测试表明:ZnO/水热炭复合材料的光催化性能较纯ZnO有明显提高,其中水热炭为19.7%时,光催化性能最佳,降解效率达到83.1%。动力学分析表明:复合材料对亚甲基蓝的光催化降解过程符合一级动力学模型。

In order to expand the application of hydrothermal carbon from forestry residues in photocatalyst carrier field, the ZnO/hydrothermal carbon composite material was obtained by one-step hydrothermal synthesis method. In this method, the raw material contained hydrothermal carbon, zinc acetate and ammonia water. The composite photocatalysts were characterized by X-ray diffraction （XRD） , scanning electron microscope （SEM）. The photocatalytic activity and degradation kinetics of the photocatalysts were studied by the degradation of methyl blue solution. The results showed that： the ZnO/hydrothermal carbon composite material can be prepared under the experimental conditions. ZnO had a hexagonal wurtzite structure and the size of ZnO significantly reduced with the increasing content of hydrothermal carbon. However, when the quantity of hydrothermal carbon reached 24.6% , the ZnO changed from rod to sheet. The photocatalytic results indicated that the composite photocatalysts exhibited higher photocatalytic activity compared with pure ZnO, and when the content of hydrothermal carbon reached 19.7%, ZnO/hydrothermal carbon exhibited the best catalytic performance, leading to as much as 83.1% reduction of MB concentration. The reaction of photocatalytic oxidation is the first order reaction in kinetics.