Zinatloo-Ajabshir Sahar, Emsaki Mehdi, Hosseinzadeh Ghader
Department of Chemical Engineering, University of Bonab, P.O. Box. 5551761167, Bonab, Iran.
Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
J Colloid Interface Sci. 2022 Aug;619:1-13. doi: 10.1016/j.jcis.2022.03.112. Epub 2022 Mar 28.
Herein, we have developed LnCeO (Ln = Er, Ho) ceramic nanostructures through a rapid and green sonochemical approach and scrutinized their photocatalytic efficiency toward degradation of toxic pollutants under sunlight. Salvia rosmarinus extract is utilized as a morphology-directing agent in the sono-synthesis of the nanostructured LnCeO (Ln = Er, Ho), for the first time. Comprehensive characterization utilizing different techniques demonstrated that introducing of rare-earth metals, erbium and holmium, affected the textural, morphological, and optical features of the nanostructured ceria. The energy gap for pure cerium dioxide nanostructure was estimated to be 3.09 eV, while the energy gap for HoCeO and ErCeO nanostructure was estimated at 2.9 and 2.66 eV, respectively. The narrowing of the energy gap was observed as a result of the introduction of rare-earth metals, erbium and holmium, especially erbium, into the nanostructured ceria. Investigation of the photocatalytic decomposition of various contaminants revealed that the introduction of erbium has remarkably enhanced the photocatalytic activity of nanostructured ceria. High photocatalytic performance (98.9%) and rate constant (0.0727 min) was observed for the ErCeO nanostructure in the removal of eriochrome Black T. Improving the optical features of ceria nanostructure as well as enhancing its specific area were reasons that could increase the photocatalytic efficiency. The photocatalytic decomposition reactions in the removal of toxic contaminants were well accorded with the Pseudo-first order reaction kinetics. Besides, the nanostructured ErCeO maintained its efficiency after ten reaction cycles and did not denote any notable decline in efficiency. The use of this novel porous nanostructure can be a potentially efficient solution for water treatment.
在此，我们通过一种快速且绿色的声化学方法制备了LnCeO（Ln = Er，Ho）陶瓷纳米结构，并研究了它们在阳光下对有毒污染物降解的光催化效率。首次将迷迭香叶提取物用作纳米结构LnCeO（Ln = Er，Ho）声合成中的形貌导向剂。利用不同技术进行的综合表征表明，引入稀土金属铒和钬会影响纳米结构二氧化铈的结构、形态和光学特性。纯二氧化铈纳米结构的能隙估计为3.09 eV，而HoCeO和ErCeO纳米结构的能隙分别估计为2.9和2.66 eV。由于将稀土金属铒和钬，特别是铒引入纳米结构二氧化铈中，观察到能隙变窄。对各种污染物光催化分解的研究表明，铒的引入显著提高了纳米结构二氧化铈的光催化活性。在去除铬黑T方面，ErCeO纳米结构表现出高光催化性能（98.9%）和速率常数（0.0727 min⁻¹）。改善二氧化铈纳米结构的光学特性以及增加其比表面积是提高光催化效率的原因。去除有毒污染物的光催化分解反应符合准一级反应动力学。此外，纳米结构的ErCeO在十个反应循环后仍保持其效率，且效率没有明显下降。这种新型多孔纳米结构的使用可能是一种潜在的高效水处理解决方案。
