Synthesis of Co-doped CeO2 nanoflower: Enhanced adsorption and degradation performance toward tetracycline in Fenton-like reaction

• Published in: Journal of alloys and compounds 2022-05, Vol.904, p.163879, Article 163879
• Main Authors: Mei, Yuqing, Zhang, Yanqiu, Li, Jiaqi, Deng, Xianhe, Yang, Yang, Yang, Qingfeng, Jiang, Baojiang, Xin, Baifu, Yao, Tongjie, Wu, Jie
• Format: Article
• Language: English
• Subjects: Acceleration; Adsorption; Catalysts; CeO2; Cerium oxides; Cobalt oxides; Fenton-like reaction; Leaching; Performance degradation; Peroxymonosulfate; Pollutant degradation; Pollutants; Structural hierarchy; Surface chemistry
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.163879

•Co-CeO2 fits Langmuir model and pseudo second order kinetics, Qm is 1.92 times higher than CeO2.•Degradation rate of Co-CeO2 is 6.7 times higher than CeO2.•Degradation is an endothermic and non-spontaneous process with Ea of 35.3 kJ/mol.•Catalytic mechanism is revealed, and •OH, SO4•- and 1O2 are involved in degradation.•77.1% of efficiency remains after 5 runs, Co ions leaching is 12 times lower than Co3O4. [Display omitted] Co-CeO2 nanoflower was prepared via a solvothermal-calcination process. Compared to CeO2, the maximum adsorption capacity increased by 1.92 times, and the tetracycline degradation rate was enhanced by 6.7 times. In Fenton-like reaction, adsorption and degradation are inseparable processes. The pollutants were enriched on the surface of catalyst by adsorption leading to the increase of the local concentration, and this was beneficial for acceleration of the degradation rate. Therefore, a catalyst with high adsorption capacity, low metal leaching and rapid activation rate toward peroxymonosulfate (PMS) was highly desirable. In this paper, Co-doped CeO2 (Co-CeO2) nanoflower was prepared via a solvothermal-calcination process. The nanoflower with a hierarchical porous structure was made up of dozens of nanosheets. Compared to CeO2, more Ce(Ⅲ) sites and defects were generated on Co-CeO2 surface, and the maximum adsorption capacity was increased by 1.92 times. Benefiting from the high activity of Co toward the activation of PMS, the degradation rate was enhanced 6.7 times. The major radicals were determined and the corresponding degradation mechanism was revealed. Additionally, Co-CeO2 nanoflower was demonstrated to be high efficient in many persistent organic pollutant degradation and also exhibited outstanding reusability after several cycles. Moreover, the leaching of toxic Co ions was 12 times lower than the referenced Co3O4. This work provides a promising approach on rational design a catalyst with high adsorption property and degradation efficiency in Fenton-like reaction for environmental remediation.