Dhanka Ajit Kumar, Pani Balaram, Agasti Nityananda
Department of Chemistry, University of Delhi, North Campus Delhi 110007 India
Department of Chemistry, Bhaskaracharya College of Applied Sciences, University of Delhi Dwarka New Delhi 110075 India.
RSC Adv. 2025 Apr 15;15(15):11774-11789. doi: 10.1039/d5ra00640f. eCollection 2025 Apr 9.
The catalytic activity of CeO can be modulated by incorporating defects and inducing strong metal-support interactions. Herein, we introduce CuO into CeO for generating oxygen vacancies (CeO ) the interaction between CuO and CeO. The resultant catalyst CuO/CeO exhibited improved performance for the photocatalytic degradation of isoproturon (a herbicide). The improvement in catalytic performance was attributed to the oxygen vacancies and interfacial charge transfer between CuO and CeO. Notably, the addition of CuO increased the oxygen vacancies in CeO, correlating with the increase in the Ce content (31.2%). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy studies substantiated the increase in surface oxygen vacancies in CeO. We investigated the oxygen vacancies quantitatively and detected the chemical states of the Cu and Ce species. Photoluminescence (PL) studies validated the role of oxygen vacancies in restraining the recombination of photogenerated electron and hole pairs, thereby improving the catalytic activity of CuO/CeO. Trapping experiments were conducted to identify the reactive species involved in the photocatalytic degradation process. Based on a thorough evaluation of the characteristics of the catalyst and photocatalysis experimental outcomes, a potential reaction mechanism was proposed. Furthermore, high-resolution mass spectrometry (HRMS) analysis was utilized to identify degradation intermediates, enabling us to outline the possible degradation pathways of isoproturon. Isoproturon (IPU) was effectively degraded under UV light with CuO/CeO compared with pristine CeO. A 95% degradation efficiency was achieved with CuO/CeO (10 mg) for the IPU solution (10 μg L) within 120 minutes. This study provides detailed insights into the structural analysis of defective CeO and an in-depth mechanism of its photocatalysis, facilitating the design of high-performance ceria-based catalysts for photocatalytic degradation of emerging contaminants in water.
通过引入缺陷和诱导强金属-载体相互作用，可以调节CeO的催化活性。在此，我们将CuO引入CeO中以产生氧空位（CeO ）以及CuO与CeO之间的相互作用。所得催化剂CuO/CeO对异丙隆（一种除草剂）的光催化降解表现出改进的性能。催化性能的提高归因于氧空位以及CuO与CeO之间的界面电荷转移。值得注意的是，CuO的添加增加了CeO中的氧空位，这与Ce含量的增加（31.2%）相关。X射线光电子能谱（XPS）和拉曼光谱研究证实了CeO中表面氧空位的增加。我们对氧空位进行了定量研究，并检测了Cu和Ce物种的化学状态。光致发光（PL）研究验证了氧空位在抑制光生电子和空穴对复合方面的作用，从而提高了CuO/CeO的催化活性。进行了捕获实验以确定光催化降解过程中涉及的活性物种。基于对催化剂特性和光催化实验结果的全面评估，提出了一种潜在的反应机制。此外，利用高分辨率质谱（HRMS）分析来鉴定降解中间体，使我们能够概述异丙隆可能的降解途径。与原始CeO相比，在紫外光下，CuO/CeO能有效降解异丙隆（IPU）。对于10 μg L的IPU溶液，10 mg的CuO/CeO在120分钟内实现了95%的降解效率。这项研究为缺陷CeO的结构分析及其光催化的深入机制提供了详细的见解，有助于设计用于光催化降解水中新兴污染物的高性能二氧化铈基催化剂。
