Herein, we successfully synthesized a series of M-CoCoPBA, where M is the rare earth metal, by a chemical precipitation method and prepared M-Co₃O₄ by air pyrolysis with M-CoCoPBA as the precursor. The catalytic performance of M-Co₃O₄ as heterogeneous catalysts was studied for activating PMS to degrade tetracycline (TC), and it is noteworthy that Er-Co₃O₄ has the strongest catalytic activity. The degradation efficiency of TC in the Er-Co₃O₄/PMS system could reach 82% as a reaction time of 4 min at 25 °C, and the catalyst also has good cyclic stability after 5 cycles. The morphology and composition of the Co₃O₄ and Er-Co₃O₄ were systematically characterized by various techniques, and it is found that ErCoO_x significantly enhanced the catalytic activity of PMS activation and TC degradation, owing to bigger surface area, more lattice defects, oxidation state of Co, and vacancy oxygen of the catalysts with Er doping, compared with CoO_x. Free radical quenching and EPR experiments showed that singlet oxygen (¹O₂), SO₄^–•, and ^•OH were generated in the ErCoO_x/PMS system. The intermediate products and degradation pathway of TC by Er-Co₃O₄/PMS system were proposed according to the results of liquid chromatography–mass spectrometry. In addition, the kinetics of activating PMS to produce active substances by Co₃O₄ and Er-Co₃O₄ catalysts was systematically explored by using isothermal titration calorimetry (ITC) technology in the temperature range of 298.19–323.19 K, and the results indicate that E_a, ΔH^⧧, ΔS^⧧, and ΔG^⧧ of Er-Co₃O₄ are all smaller than those of Co₃O₄ and demonstrate the inner mechanism of bigger rate constant and much higher catalytic property of Er-Co₃O₄.

中文翻译：

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稀土金属掺杂Co3O4复合催化剂的制备及其性能及降解四环素的热力学研究


在此，我们通过化学沉淀法成功合成了一系列M-CoCoPBA，其中M为稀土金属，并与M通过空气热解制备了M-Co ₃ O ₄ -CoCoPBA作为前体。研究了M-Co ₃ O ₄ 作为多相催化剂活化PMS降解四环素(TC)的催化性能，值得注意的是Er-Co ₃ 催化活性最强。 Er-Co ₃ O ₄ /PMS 体系中 25 ℃反应时间 4 min 时 TC 降解效率可达 82%，催化剂还具有良好的催化性能。 5个循环后的循环稳定性。通过多种技术对Co ₃ O ₄ 和Er-Co ₃ O ₄ 的形貌和组成进行了系统的表征，并研究发现，ErCoO _x 由于Er掺杂催化剂的比表面积更大、晶格缺陷更多、Co的氧化态和空位氧较多，显着增强了PMS活化和TC降解的催化活性。 CoO _x 。自由基猝灭和 EPR 实验表明，单线态氧 ( ¹ O ₂ )、SO ₄ ^–• 和 ^• /PMS 系统中生成。根据液相色谱-质谱联用结果，提出了Er-Co ₃ O ₄ /PMS系统对TC的中间产物和降解途径。此外，Co ₃ O ₄ 和Er-Co ₃ O ₄ 催化剂活化PMS产生活性物质的动力学为利用等温滴定量热法（ITC）技术在298.19-323的温度范围内进行系统探索。19 K，结果表明 Er-Co ₃ 、ΔS ^⧧ 和 ΔG ^⧧ > O ₄ 均小于Co ₃ O ₄ ，证明了Co ₃ O ₄ 具有更大的速率常数和更高的催化性能的内在机制Er-Co ₃ O ₄ 。