Preparation method of nitrogen sulfur co-doped carbon nanosheet material

The invention relates to a preparation method of a nitrogen sulfur co-doped carbon nanosheet material. The method includes the steps of: 1) dissolving sodium carboxymethylcellulose in water, and stirring the substances evenly to obtain a sodium carboxymethylcellulose solution; 2) adding a molten salt into the sodium carboxymethylcellulose solution obtained in step 1), and stirring the substances evenly to obtain a mixed solution, with the molten salt being any one or a mixture of several of sodium chloride, potassium chloride, sodium nitrate and potassium nitrate; 3) subjecting the mixed solution obtained in step 2) to freeze drying to obtain a dried sample; 4) conducting carbonization treatment on the dried sample obtained in step 3) at 700-900DEG C to obtain a carbon nanosheet material crude product; and 5) conducting washing and drying on the carbon nanosheet material crude product obtained in step 4), thus obtaining a carbon nanosheet material finished product. The process adoptedby the invention is simpl