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2D layered carbocatalysts, peroxymonosulfate activation, ZIF-8, Fenton-like reaction, mediated electron transfer
Abstract:
Two-dimensional (2D) carbon materials are receiving increasing attention due to their partly groundbreaking performance in catalysis and electrochemistry based on distinct physiochemical and textural properties. We focus on the challenge to directly achieve a well-developed layered morphology with a high doping level of heteroatoms as the active sites, a standard conflict of interests of high-temperature synthesis. Here, we report a dual-templating strategy to yield graphene-like layered carbon (GLC) by direct carbonization of a texturally prealigned zeolitic imidazolate framework-8 (ZIF-8). The recrystallization of ZIF-8 in an aqueous NaCl solution discloses a 2D packing mode that was retained after freeze-drying with recrystallized NaCl as an exotemplate and a space-confining nanoreactor. Further promoted by the chemical interaction of NaCl in promoting and stabilizing the carbonization process, the final product came with a well-separated layered morphology and high amounts of heteroatoms (16.6 wt % N and 7.5 wt % O). The structurally and catalytically special GLC functioned well in activating peroxymonosulfate-based Fenton-like reactions. It was shown that the reaction proceeded via nonfree-radical-mediated pathways, as reflected in significantly enhanced electron-transfer processes and ultrafast kinetics for pollutant removal. The proposed strategy is expected to afford a broader applicability for the bottom-up design of 2D carbon materials.
