ZnO/CdS复合光催化剂的制备及降解四环素类抗生素

Preparation of ZnO/CdS composite photocatalyst and its degradability on tetracycline antibiotic

利用单晶Si辅助水热法低温合成了ZnO/CdS复合光催化剂,采用XRD、SEM、Dr-UV-vis等技术对材料结构和形貌进行表征,并对四环素类抗生素进行光催化降解研究。结果表明,当锌源与镉源的物料摩尔比为25∶1、反应时间10h条件下,可获得形貌最佳的ZnO/CdS复合物,即尺寸为1μm的具有孔结构的棒状ZnO骨架表面黏附了尺寸在几十纳米的CdS粒子。CdS的复合明显降低ZnO/CdS的带隙能至2.87e V,在日光照射下反应120min,对盐酸四环素(TC)、土霉素(OTC)和强力霉素(DC)3种四环素类抗生素的光催化降解率分别达到81.65%、70.68%和54.61%,降解反应速率很快,符合一级反应动力学方程;在紫外光照射下几乎可以完全降解这3种抗生素,证明了该复合材料的高催化效率。

ZnO/CdS nanocomposites were synthesized at low temperature by single crystal Si assisted hydrothermal method. The structure and morphology of the products were examined by X-ray diffraction（XRD）,scanning electronic microscopy（SEM）,ultraviolet visible diffuse reflectance （Dr-UV-vis）,and carried on the research of photocatalytic degradation of tetracycline antibiotics. The result shows that the ZnO/CdS of optimal morphology was obtained at zinc and cadmium molar ration of 25∶1 reacted for 10 hour,there are several CdS nanoparticles adhere to the surface of porous ZnO rod skeleton. CdS component makes band gap of ZnO reduced to 2.87eV,leading to the degradation of tetracycline（TC）,oxytetracycline（OTC） and doxycycline（DC） under xenon light reached 81.65%, 70.68% and 54.61% respectively. Moreover,ZnO/CdS composites can almost complete the degradation of three kinds of antibiotics under UV irradiation,proving high catalytic efficiency of the composite catalyst.