片花状ZnO@碳球核壳结构的制备及太阳光催化性能

Preparation and Sunlight Photocatalytic Performance of Flower-like ZnO@carbon Sphere Core-Shell Structure

采用水热法合成具有核壳结构的片花状ZnO@碳球系列复合物(ZnO@C)。利用X射线衍射(XRD),扫描电子显微镜(SEM),X射线光电子能谱(XPS),红外光谱(FTIR),紫外可见漫反射光谱(UV-Vis DRS),荧光光谱(PL)以及N2吸附-脱附等技术对所合成样品进行表征,结果表明,碳球被ZnO纳米片包裹形成具有核壳结构的片花状复合物,碳球的存在增加了ZnO对可见光的吸收,有效抑制了光生电子空穴对的复合。在模拟太阳光下,对活性染料GR黑及甲硝唑的光催化降解测试结果显示,ZnO@C系列复合物的光催化性能均高于纯ZnO,其中ZnO@C-2样品表现出最好的光催化性能,其光催化降解GR黑和甲硝唑的速率分别为纯ZnO的4.2倍和2.1倍。

A series of nanosheets assembled flower-like core-shell ZnO@carbon sphere （ZnO@C）composites were prepared by hydrothermal method. The as-prepared samples were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, X-ray photoelectron spectroscope （XPS）, Fourier transform infrared spectroscopy （FTIR）, UV-Vis diffuse reflectance spectroscope （UV-Vis DRS）, photoluminescence （PL）and N2 adsorption-desorption determination. The results showed that carbon spheres were coated by ZnO nanosheets forming core-shell structure. The presence of carbon spheres in ZnO@C composites not only improved the absorption of ZnO in the visible light region but also inhibited the recombination of photogenerated electrons and holes. Under simulated sunlight irradiation, the photodegradation of Reactive dye GR black and metronidazole by samples were tested, the results showed that all ZnO@C composites exhibited enhanced photocatalytic performance compared to pure ZnO. Especially, the ZnO@C-2 sample showed the best photocatalytic performance, the rate constant of which was about 4.2 times that of pure ZnO for GR black degradation and 2.1 times for metronidazole degradation, respectively.