Chen Xiaoqing, Wu Zhansheng, Liu Dandan, Gao Zhenzhen
School of Chemistry and Chemical Engineering/The Key Lab. for Green Processing of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi, 832003, People's Republic of China.
Nanoscale Res Lett. 2017 Dec;12(1):143. doi: 10.1186/s11671-017-1904-4. Epub 2017 Feb 21.
Zinc oxide (ZnO) photocatalysts were synthesized by sol-gel method using zinc acetate as precursor for degradation of azo dyes under UV irradiation. The resultant samples were characterized by different techniques, such as XRD, SEM, and EDX. The influence of preparation conditions such as calcination temperature and composite ratio on the degradation of methyl orange (MO) was investigated. ZnO prepared with a composite ratio of 4:1 and calcination temperature of 400 °C exhibited 99.70% removal rate for MO. The effect of operation parameters on the degradation was also studied. Results showed that the removal rate of azo dyes increased with the increased dosage of catalyst and decreased initial concentration of azo dyes and the acidic condition is favorable for degradation. Furthermore, the kinetics and scavengers of the reactive species during the degradation were also investigated. It was found that the degradation of azo dyes fitted the first-order kinetics and superoxide ions were the main species. The proposed photocatalyst can efficiently and rapidly degrade azo dyes; thus, this economical and environment-friendly photocatalyst can be applied to the treatment of wastewater contaminated with synthetic dyes.
采用溶胶 - 凝胶法，以醋酸锌为前驱体合成氧化锌（ZnO）光催化剂，用于在紫外光照射下降解偶氮染料。通过X射线衍射（XRD）、扫描电子显微镜（SEM）和能谱分析（EDX）等不同技术对所得样品进行表征。研究了煅烧温度和复合比例等制备条件对甲基橙（MO）降解的影响。复合比例为4:1且煅烧温度为400℃制备的ZnO对MO的去除率达到99.70%。还研究了操作参数对降解的影响。结果表明，偶氮染料的去除率随着催化剂用量的增加以及偶氮染料初始浓度的降低而增加，酸性条件有利于降解。此外，还研究了降解过程中活性物种的动力学和清除剂。发现偶氮染料的降解符合一级动力学，超氧离子是主要的活性物种。所制备的光催化剂能够高效、快速地降解偶氮染料；因此，这种经济环保的光催化剂可应用于处理受合成染料污染的废水。
