Carbon Materials Research Group, Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18071, Granada, Spain.
Carbon Materials Research Group, Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18071, Granada, Spain.
Environ Res. 2023 Jul 1;228:115757. doi: 10.1016/j.envres.2023.115757. Epub 2023 Mar 25.
Fe-doped carbon xerogels with a highly developed graphitic structure were synthesized by a one-step sol-gel polymerization. These highly graphitic Fe-doped carbons are presented as promising dual-functional electro-Fenton catalysts to perform both the electro-reduction of O to HO and HO catalytic decomposition (Fenton) for wastewater decontamination. The amount of Fe is key to the development of this electrode material, since affects the textural properties; catalyzes the development of graphitic clusters improving the electrode conductivity; and influences the O-catalyst interaction controlling the HO selectivity but, at the same time is the catalyst for the decomposition of the electrogenerated HO to OH radicals for the organic pollutants oxidation. All materials achieve the development of ORR via the 2-electron route. The presence of Fe considerably improves the electro-catalytic activity. However, a mechanism change seems to occur at around -0.5 V in highly Fe-doped samples. At potential lower than -0.5 eV, the present of Fe species or even Fe-O-C active sites favour the selectivity to 2e-pathway, however at higher potentials, Fe species are reduced favoring a O-O strong interaction enhancing the 4e-pathway. The Electro-Fenton degradation of tetracycline was analyzed. The TTC degradation is almost complete (95.13%) after 7 h of reaction without using any external Fenton-catalysts.
通过一步溶胶-凝胶聚合合成了具有高度发达石墨结构的 Fe 掺杂碳干凝胶。这些高度石墨化的 Fe 掺杂碳作为有前途的双功能电芬顿催化剂，可同时进行 O 到 HO 的电还原和 HO 催化分解（芬顿）以净化废水。Fe 的量是开发这种电极材料的关键，因为它影响结构性质；催化石墨簇的发展，提高电极导电性；并影响 O-催化剂相互作用，控制 HO 的选择性，但同时也是电生成 HO 分解为 OH 自由基以氧化有机污染物的催化剂。所有材料都通过 2 电子途径实现 ORR 的发展。Fe 的存在大大提高了电催化活性。然而，在高 Fe 掺杂样品中，似乎在约-0.5 V 时发生了机制变化。在低于-0.5 eV 的电位下，Fe 物种甚至 Fe-O-C 活性位有利于 2e-途径的选择性，然而在更高的电位下，Fe 物种被还原有利于 O-O 强相互作用，增强 4e-途径。分析了四环素的电芬顿降解。在不使用任何外部芬顿催化剂的情况下，反应 7 小时后 TTC 的降解几乎完成（95.13%）。
