Kanghui Zhang

Organic pollutants entering water bodies lead to severe water pollution, posing a threat to human health. The activation of persulfate advanced oxidation processes using carbon materials derived from MOFs as substrates can efficiently treat wastewater contaminated with organic pollutants. This research uses NH₂-MIL-101(Fe) as a substrate, doped with Fe²⁺ and Co²⁺, to prepare Fe/Co-CNs through a one-step carbonization method. The surface morphology, pore structure, and chemical composition of Fe/Co-CNs were investigated using characterization techniques such as XRD, SEM, TEM, XPS, FT-IR, BET, and Raman. A comparative study was conducted on the performance of catalysts with different Fe/Co ratios in activating PMS for the degradation of organic pollutants, as well as the effects of various influencing factors (the dosage of Fe/Co-CNs, the amount of peroxymonosulfate (PMS), the initial pH of the solution, the TC concentration, and inorganic anions) on the catalyst’s activation of persulfate for TC degradation. Through radical quenching experiments and post-degradation XPS analysis, the active radicals in the FeCo-CNs/PMS system were investigated to explain the possible mechanism of TC degradation in the Fe/Co-CNs/PMS system. The results indicate that Fe/Co-CNs-2 (with a Co²⁺ doping amount of 20%) achieves a degradation rate of 93.34% for TC (tetracycline hydrochloride) within 30 min when activating PMS, outperforming other Co²⁺ doping amounts. In addition, singlet oxygen (¹O₂) is the main reactive species in the reaction system.

This study presents a novel Fe-CNs-P/S carbon composite material, synthesized by doping elements P and S into NH₂-MIL-101 (Fe) using the carbonization method. The material’s application in sustainable water treatment was evaluated, focusing on its effectiveness in activating persulfate for pollutant degradation. The research thoroughly investigates the synthesis process, structural characteristics, and performance in degrading pollutants. The results indicate that Fe-CNs-P/S-5 with 50% P and S co-doping is higher than that of other samples, where the degradation rate of TC in 30 min is as high as 98.11% under the optimum conditions, that is temperature at 25 °C, 0.05 g/L of catalyst concentration, and 0.2 g/L of PMS concentration. The composite material demonstrates robust versatility and stability, maintaining high degradation efficiency across multiple organic pollutants, with no significant reduction in catalytic performance after four cycles. Furthermore, the free radical quenching experiments display that the singlet oxygen ¹O₂ is the main active species. It is demonstrated that the doping of P and S play a role in the enhancement of PMS activation over the Fe-CNs-P/S catalyst. This material demonstrates remarkable efficacy in treating a range of organic contaminants and exhibits excellent reusability, presenting a promising approach for enhancing sustainability in water treatment applications.

This study presents a novel Fe-CNs-P/S carbon composite material, synthesized by doping elements P and S into NH2-MIL-101 (Fe) using carbonization method. The material's application in sustainable water treatment was evaluated, focusing on its effectiveness in activating persulfate for pollutant degradation. The research thoroughly investigates the synthesis process, structural characteristics, and performance in degrading pollutants. Results indicate that Fe-CNs-P/S-5 with 50% P and S co-doping is higher than that of other samples, where the degradation rate of TC in 30min is as high as 98.11% under the optimum conditions, that is temperature at 25 ℃, 0.05 g/L of catalyst concentration, and 0.2 g/L of PMS concentration. The composite material demonstrates robust versatility and stability, maintaining high degradation efficiency across multiple organic pollutants, with no significant reduction in catalytic performance after four cycles. Furthermore, the free radical quenching experiments displays that the singlet oxygen 1O2 is the main active species. It is demonstrated that the doping of P and S play a role in the enhancement of PMS activation over the Fe-CNs-P/S catalyst. This material demonstrates remarkable efficacy in treating a range of organic contaminants and exhibits excellent reusability, presenting a promising approach for enhancing sustainability in water treatment applications.

Peroxydisulfate activation has garnered a lot of interest due to its benefits of broad adaptability, strong anti-interference ability, and powerful oxidation capacity. Due to their low cost and potent action, carbon materials are new green catalysts that have garnered interest. In order to effectively degrade organic contaminants in water by activating peroxydisulfate, carbon compounds are currently commonly used. Better metal ions for activating peroxydisulfate include Fe2+ and Co2+, and these metal ions can be encapsulated in carbon compounds made by calcinating metal organic framework（MOFs ）as precursors. The synthesis of carbon compounds from MOF precursors as well as their effectiveness and mechanism in reducing organic pollutants in peroxydisulfate systems. The following are the specific research contents: NH2-MIL-101 (Fe/Co) bimetallic MOFs material was synthesized by hydrothermally altering the Fe3+ to Co2+ ratio, followed by the carbonization of Fe/Co-CNs. XRD, SEM, TEM, FT-IR, and XPS were used to analyze the materials' morphology, structure, and chemical make-up. The results demonstrate that Fe/Co-CNs-2 (Co2+ doping concentration approaches 20%) has a stable three-dimensional carbon structure and effectively incorporated Co ions into the carbon material. The simultaneous encapsulation of both Fe and Co metals by the three-dimensional carbon skeleton ensures material stability and reaction activity. Tetracycline hydrochloride was reported to degrade more quickly in Fe/Co-CNs-2 than in other Co2+ doping concentrations within 30 minutes of peroxymonosulfate（PMS） activation. The degradation rate of Fe/Co-CNs-2 for 20 mg/L TC was determined to be 93.34% within 30 minutes under the following conditions: Fe/Co-CNs-2 concentration of 0.1 g/L, PMS concentration of 0.2 g/L, and pH of 7.33. The catalyst also demonstrates good stability. Last but not least, the Fe/Co-CNs-2 free radical quenching experiment revealed that singlet oxygen (1O2) is the primary active species in the reaction system, and a potential mechanism was examined by combining degradation and XPS analysis.