Abstract：ZIF-8 was prepared by solvothermal synthesis, and N-doped porous carbon was obtained by calcining in an inert atmosphere at 500~800oC. The influence of high temperature carbonization on the structure evolution of ZIF-8 and the enhancement mechanism of photocatalytic degradation of methylene blue were systematically studied. The ZIF-8 particles collapsed and agglomerated after carbonization, forming Zn-C complex with graphite phase structure. The carbon layer, as a receptor, could rapidly transfer photogenerated electrons and inhibit electron hole pair recombination. At the same time, oxidized H-N-C=O and C-O functional groups were generated on the surface, which could promote the formation of free radicals in the photocatalytic reaction. C700/ZIF-8 had the highest transient photoelectric current density and the smallest electrochemical impedance, the spectral absorption range was extended to 200~900nm range. In addition, a great number of superoxide free radicals and hydroxyl free radicals were generated during the photocatalytic process, resulting in the highest methylene blue photocatalytic degradation efficiency of 97%.
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