铁酸钴基复合催化剂的制备及其活化PMS降解刚果红性能

Preparation of Cobalt Ferrate-Based Composite Catalysts and Their Performance in Activating PMS to Degrade Congo Red

摘要: 铁氧体作为活化过硫酸盐的催化剂能够表现优异的催化性能，但由于其本身高表面能，铁氧体粒子容易团聚，使得催化性能下降。本研究采用铁酸钴与聚苯胺(PANI)复合，制备了一种复合催化剂CoFe₂O₄@PANI (CFP)来活化过硫酸盐(PMS)降解刚果红(CR)。系统表征显示，CoFe₂O₄纳米颗粒均匀沉积在PANI长链纤维上；CFP具有43.52 emu·g⁻¹的强磁性，可实现高效磁分离。催化降解实验表明，CFP/PMS系统对CR的去除率远高于CoFe₂O₄/PANI/PMS系统。在[CR] = 50 mg/L、[PMS] = 1 mM、0.2 g/L CFP、起始pH = 7和T = 25˚C条件下，最大降解效率达到99.2%。活性氧(ROS)淬灭实验表明，¹O₂、$O_2^{·-}$ 和$S{O}_4^{·-}$ 主要参与了CR的消除。共存阴离子实验表明，$S{O}_4^{2-}$ 、$H_{2}P{O}_4^{-}$ 和Cl⁻对CR降解无明显影响，$C{O}_3^{2-}$ 对催化过程有轻微影响，说明该催化剂的环境适应能力较强。

Abstract: Ferrite can exhibit excellent catalytic performance as a catalyst for activation of persulfate, but due to its own high surface energy, ferrite particles are prone to agglomeration, which makes the catalytic performance decrease. In this study, a composite catalyst CoFe₂O₄@PANI (CFP) was prepared to activate persulfate (PMS) for degradation of Congo red (CR) using cobalt ferrite complexed with polyaniline (PANI). Systematic characterisation showed that CoFe₂O₄ nanoparticles were uniformly deposited on the long-chain fibres of PANI; CFP possessed a strong magnetic property of 43.52 emu·g⁻¹, which enabled efficient magnetic separation. The catalytic degradation experiments showed that the removal of CR by the CFP/PMS system was much higher than that by the CoFe₂O₄/PANI/PMS system. The maximum degradation efficiency reached 99.2% under the conditions of [CR] = 50 mg/L, [PMS] = 1 mM, 0.2 g/L CFP, starting pH = 7, and T = 25˚C. Reactive oxygen species (ROS) quenching experiments showed that ¹O₂, $O_2^{·-}$ and $S{O}_4^{·-}$ were mainly involved in the elimination of CR. Coexisting anion experiments showed that $S{O}_4^{2-}$ , $H_{2}P{O}_4^{-}$ and Cl⁻ had no significant effect on CR degradation, and $C{O}_3^{2-}$ had a slight effect on the catalytic process, which indicated that the catalyst had a strong ability to adapt to the environment.