Corn bran-based three-dimensional multi-level pore structure carbon material and preparation method thereof

The invention relates to a corn bran-based three-dimensional multi-level pore structure carbon material and a preparation method thereof, which belong to three-dimensional multi-level pore structure carbon materials. According to the corn bran-based three-dimensional multi-level pore structure carbon material and the preparation method, renewable biomass corn bran with low price and rich yield is adopted as a carbon source, the novel three-dimensional multi-level pore structure carbon material is effectively prepared by adopting a simple template-free method which is easy to industrialize, and the problems of process complexity, time consumption, high cost and difficulty in realizing industrialization of a template method are solved. The corn bran-based three-dimensional multi-level pore structure carbon material is prepared in the following steps of cutting the corn bran into pieces, drying after water washing treatment, then adding to a KOH solution, returning under a water bath condition, sieving after cooling, then roasting solids in high-purity nitrogen atmosphere, then cleaning with a hydrochloric acid solution, centrifuging, washing with water and drying. The specific surface area of the carbon material reaches up to 927m g-1, macropore, mesopore and micropore structures are mutually communicated, the pore size distribution is centered, an oxygen enrichment functional group is contained, and the content is 12% to 17%.