Zhang Luhong, Xiong Zhigang, Li Li, Burt Ryan, Zhao X S
School of Chemical Engineering, The University of Queensland, Brisbane, Australia.
School of Chemical Engineering, The University of Queensland, Brisbane, Australia.
J Colloid Interface Sci. 2016 May 1;469:224-230. doi: 10.1016/j.jcis.2016.02.005. Epub 2016 Feb 2.
In this work ZnAl-layered double oxide composites (LDO) were developed to remove organic dyes in wastewater by adsorption and photocatalysis. Various LDO composites were synthesized by adjusting synthetic parameters including the molar ratio of Zn to Al, and calcination temperature. LDO adsorption and photocatalytic properties for decomposition of organic dyes were also investigated. Orange II sodium salt (OrgII), an azo dye and water contaminant, was chosen as the model to investigate the properties of LDOs compared with commercial ZnO, TiO2 (P25) and ZnO-LDH. The adsorption and photocatalytic performance results showed that LDO composites significantly enhanced adsorption-photocatalytic performance for OrgII degradation. LDO at the Zn/Al molar ratio of 2 (2)LDO has the best adsorption capacity (800.8 mg/g of OrgII for (2)LDO), and improved photocatalytic activity (74.3% of OrgII decomposition for (2)LDO). It is believed that the better adsorption properties of LDO are due to the adsorption and intercalation of dyes in the interlayer during LDO's rehydration process. ZnO/ZnAl-rehydrated layered double hydroxide composites (ZnO-rLDH) after rehydration of LDOs in aqueous solution was also obtained. After restoration in water, the structure and morphology of ZnO-rLDHs were characterized by XRD, FTIR, SEM/TEM, N2 adsorption/desorption and UV-vis-DRS. Finally, the relations between the structural features of the ZnO-rLDH composites and the adsorption properties and photocatalytic activity of LDO was studied.
在本研究中，开发了锌铝层状双氧化物复合材料（LDO），用于通过吸附和光催化去除废水中的有机染料。通过调整合成参数，包括锌与铝的摩尔比和煅烧温度，合成了各种LDO复合材料。还研究了LDO对有机染料分解的吸附和光催化性能。选择橙色II钠盐（OrgII），一种偶氮染料和水污染物，作为模型，以研究LDO与商业ZnO、TiO2（P25）和ZnO-LDH相比的性能。吸附和光催化性能结果表明，LDO复合材料显著提高了对OrgII降解的吸附-光催化性能。锌/铝摩尔比为2的LDO（2）LDO具有最佳吸附容量（（2）LDO对OrgII的吸附容量为800.8 mg/g），并提高了光催化活性（（2）LDO对OrgII的分解率为74.3%）。据信，LDO更好的吸附性能是由于在LDO的再水化过程中，染料在层间的吸附和插层作用。还获得了LDO在水溶液中再水化后的ZnO/ZnAl再水化层状双氢氧化物复合材料（ZnO-rLDH）。在水中恢复后，通过XRD、FTIR、SEM/TEM、N2吸附/脱附和UV-vis-DRS对ZnO-rLDHs的结构和形貌进行了表征。最后，研究了ZnO-rLDH复合材料的结构特征与LDO的吸附性能和光催化活性之间的关系。
