Department of Civil Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong, People's Republic of China.
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University , Shanghai 200092, People's Republic of China.
Environ Sci Technol. 2016 Mar 15;50(6):3119-27. doi: 10.1021/acs.est.5b05974. Epub 2016 Mar 3.
Copper-iron bimetallic oxides have shown great potential for powerful radical production by activating peroxides. In this work, CuFeO2 rhombohedral crystals (RCs) were synthesized and used as heterogeneous catalysts for peroxymonosulfate (PMS) activation under various conditions. Sulfadiazine, a widely used veterinary sulfonamide, was used as a target pollutant to evaluate the efficiency of this combination. The results showed that of all the catalysts tested, the CuFeO2 RCs had the greatest reactivity. Under conditions of 0.1 g L(-1) CuFeO2 RCs and 33.0 μM PMS, the nearly complete degradation of sulfadiazine occurred within 24 min. A synergistic catalytic effect was found between solid Cu(I) and Fe(III), probably due to the accelerated reduction of Fe(III). The two activation stages that produced different radicals (hydroxyl radicals followed by sulfate radicals) existed when solid Cu(I) was used as the catalyst. The CuFeO2 RCs had a higher PMS utilization efficiency than CuFe2O4, probably because the Cu(I)-promoted reduction of solid Fe(III). A total of 10 products were identified, and their evolution was explored. On the basis of the evidence of oxidative product formation, we proposed four possible pathways of sulfadiazine degradation.
铜铁双金属氧化物通过激活过氧化物显示出产生强大自由基的巨大潜力。在这项工作中，合成了菱面体晶型的 CuFeO2（RC），并将其用作过一硫酸盐（PMS）在各种条件下的非均相催化剂。磺胺嘧啶是一种广泛使用的兽医磺胺类药物，被用作评估这种组合效率的目标污染物。结果表明，在所测试的所有催化剂中，CuFeO2 RC 的反应性最强。在 0.1 g L(-1) CuFeO2 RC 和 33.0 μM PMS 的条件下，磺胺嘧啶在 24 分钟内几乎完全降解。在固体 Cu(I)和 Fe(III)之间发现了协同催化作用，这可能是由于 Fe(III)的加速还原。当使用固体 Cu(I)作为催化剂时，存在产生不同自由基（羟基自由基随后是硫酸根自由基）的两个活化阶段。RCs 比 CuFe2O4 具有更高的 PMS 利用率，这可能是因为 Cu(I)促进了固体 Fe(III)的还原。总共鉴定出 10 种产物，并对其演化进行了探讨。基于氧化产物形成的证据，我们提出了磺胺嘧啶降解的四条可能途径。
