Preparation of ZIF-67 derived Co3O4 composite non-homogeneous catalysts with cerium oxide for the efficient degradation of Rhodamine B

• Published in: Inorganic chemistry communications Vol. 170; p. 113132
• Main Authors: Tong, Lin, Xiang, Dong, Li, Zhenxiang, Ma, Yuqin, Zhao, Lang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2024
• Subjects: Advanced catalytic oxidation; Rhodamine B; Water treatment; ZIF-Co3O4@CeO2; Water treatment; Rhodamine B; ZIF-Co3O4@CeO2; Advanced catalytic oxidation
• ISSN: 1387-7003
• DOI: 10.1016/j.inoche.2024.113132

The Ce/Co-ZIF precursor was obtained by introducing different amounts of Ce ions on the basis of ZIF-67 by liquid-phase method, and then ZIF-Co3O4@CeO2 was obtained by pyrolysis. The prepared composites were then characterised and tested by different instruments and characterisation methods. In addition, the effects of different influencing factors on the degradation of Congo red dye by this catalytic system were investigated, and it was found that the ZIF-Co3O4@CeO2 catalyst was excellent for the degradation of 400 mg/L rhodamine B dye within 30 min. [Display omitted] •ZIF-Co3O4@CeO2 non-homogeneous catalysts were synthesised by pyrolysis of ZIF-67 by introducing different amounts of Ce onto ZIF-67 using a liquid phase method.•The ZIF-Co3O4@CeO2 non-homogeneous catalyst was used to activate potassium persulfate to produce free radicals for the degradation of rhodamine B dye.•When the concentration of Congo red was 400 mg/L, ZIF-Co3O4@CeO2 had excellent catalytic effect as a catalyst, and the degradation rate of Congo red could reach 95.6 % in 30 min. The textile printing and dyeing industry produces a significant amount of wastewater, which is challenging to degrade due to its high organic concentration, complex composition, and high chromaticity. This type of wastewater is considered one of the most difficult to treat. In recent years, advanced catalytic oxidation based on sulfate radicals (SO4−) can efficiently degrade printing and dyeing wastewater. Seeking non-homogeneous catalysts for the activation of the radicals is the key problem to be solved nowadays. In this study, Ce/Co-ZIF precursor was obtained by stirring and precipitation, and the ZIF-67-derived non-homogeneous catalyst of Co3O4 and CeO2 was successfully synthesised by calcination for the efficient catalytic degradation of Rhodamine B (RhB) dye. The morphological structure and elemental distribution of the non-homogeneous catalysts were observed using SEM, TEM, XRD, and XPS. Additionally, the factors that affect the degradation of RhB dye were investigated. These factors were adjusted individually, from CeO₂ loading, pH, material dosing, to persulfate (PS) dosing, and it was determined that the rate of RhB degradation also increased from the initial 92 % to a value of 97.1 %. It was found that under the optimal conditions of a CeO2 loading percentage of 0.44, pH of 7, and composite material and potassium persulfate dosage of 5 mg and 0.4 g/L, respectively, the catalytic system achieved a degradation rate of 97.5 % of RhB dye within 30 min. Then the non-homogeneous catalyst could still maintain the good catalytic degradation effect after 5 cycles of regeneration experiments. Therefore, the ZIF-Co3O4@CeO2 non-homogeneous catalyst has a good potential for wastewater treatment and provides a new way for the application of high performance catalysts in the future.