微波辅助制备纳米ZnO及其光催化降解染料的性能

以硝酸锌、氢氧化钠为原料,聚乙二醇400(PEG 400)为溶剂,采用微波加热共沉淀法制备纳米ZnO,并采用X射线衍射、场发射电镜及紫外-可见漫反射对样品进行表征;考察纳米ZnO对结晶紫(CV)及刚果红(CR)的光催化降解性能,以λ=365nm的紫外光为光源,考察了催化剂投加量、染液浓度、pH值以及催化时间对催化效率的影响。实验结果表明,在较少的投加量下,纳米ZnO对50mg/L的CV和CR染液的降解率可分别达到98.8%和97.4%,pH值对两种染料的光催化效果影响不大。CR及CV染液的光催化降解均符合一级动 力学。

Photocatalytic degradation of dyes by nano-ZnO prepared with microwave assistance

ZnO nanoparticles were prepared by microwave-assisted precipitation method using zinc nitrate and sodium hydroxide as raw materials and polyethylene glycol-400 as solvent. The prepared samples were characterized by means of XRD,FE-SEM and UV-Vis absorption spectra,respectively. The photocatalytic performance of nano-ZnO was carried out by degrading crystal violet and Congo red under UV light (λ=365nm) irradiation. Catalyst dosage,dyes concentration,pH value and reaction time were investigated to make clear how the parameters influenced the photocatalytic performance of nano-ZnO. The results show that the degradation efficiency of 50mg/L CV and CR could reach 98.8% and 97.4%,respectively. The pH value has little impact on dyes photocatalysis degradation and the degradation of CV and CR fit the first-order kinetic process.