单原子Co-C-N催化过一硫酸盐降解金橙Ⅱ

采用模板蚀刻法合成单原子Co-C-N催化剂并催化过一硫酸盐(PMS)降解偶氮染料金橙Ⅱ(AO7).考察了催化剂投加量、PMS浓度、pH值和染料废水中常见的Cl^-对Co-C-N/PMS体系去除AO7的影响,探讨了体系的反应机理,分析了矿化能力和催化剂重复利用性能.结果表明,在Co-C-N/PMS体系中,反应随着催化剂投加量和PMS浓度的升高而加快,pH=3.0~9.0的范围内均能有效去除AO7.中性条件下,当Co-C-N投加量50mg/L、PMS浓度1.0mmol/L、AO7浓度0.05mmol/L时,AO7可在10min内被完全去除.非均相体系活化产生的SO₄·^-是降解AO7的主要活性物种,基于C基诱导PMS产生的¹O₂也通过非自由基体系参与了降解反应,反应主要发生在催化剂表面.Co-C-N/PMS体系对AO7具有优良的去除能力和矿化效果.相较于单独Co-C-N吸附AO7过程,Co-C-N/PMS体系在提高反应速率的同时极大提升了催化剂的重复利用性能.

Degradation of AO7 with peroxymonosulfate catalyzed by Co-C-N single atom

Monoatomic Co-C-N catalyst was synthesized by a template etching method and then was used to activate peroxymonosulfate (PMS) for degradation of decolorize azo dye orange 7 (AO7). The effects of catalyst dosage, PMS concentration, pH value of reaction medium and Cl^- commonly exists in dye wastewater on the removal of AO7 in Co-C-N/PMS system were systematically evaluated. The reaction mechanism was inferred, the mineralization ability and the reuse of catalyst were investigated. Experimental results showed that Co-C-N can effectively activate PMS to degrade AO7, and the reaction rate for AO7 removal can be accelerated with an increase in Co-C-N dosage and PMS concentration. AO7 can be removed effectively in the range of pH=3.0 to 9.0. When the concentration of Co-C-N dosage、the PMS and AO7 concentration were 50mg/L、1.0mmol/L and 0.05mmol/L respectively, AO7 can be completely removed within 10min under a neutral condition. SO₄·^- produced by PMS activation of heterogeneous system was the main active species for the degradation of AO7, and ¹O₂ produced by C-induced PMS was also involved in the degradation reaction through non-free radical system. The oxidation reaction mainly occurs on the surface of the catalyst. Co-C-N/PMS system has excellent removal ability and strong mineralization effect for AO7. Compared with the single Co-C-N adsorption process of AO7, Co-C-N/PMS system not only can increases the reaction rate, but also greatly improves the recyclability of the catalyst.