Preparation method of activated carbon containing sulfur and nitrogen

The invention discloses a preparation method of activated carbon containing sulfur and nitrogen. The method comprises the steps of adding amines and aldehydes to a reactor, adjusting the pH value to be 8-9 by using an alkali solution, raising the temperature to 50-59 DEG C under agitation, and keeping a constant temperature for 10-30min; adding phenols dissolved into absolute ethyl alcohol to the solution for refluxing for 1-3h, cooling to a room temperature and carrying out vacuum drying to remove remaining ethanol, and then solidifying; and carrying out carbonization in an inert atmosphere, raising the room temperature to 600-850 DEG C at a heating rate of 3-5 DEG C/min under inert atmosphere protection, activating for 1-3h, naturally cooling to the room temperature, washing to be neutral by using deionized water, and drying to obtain the activated carbon containing sulfur and nitrogen. The activated carbon has a high specific surface area, and the surface and a bulk phase contain nitrogen and sulfur at the