▎ 摘　　要

NOVELTY - Preparing a papyrus-based photothermal interface evaporation material, comprises placing the cattail in a tube furnace and heating to 350-950degrees Celsius at 3-10degrees Celsius/minute, carbonizing for 1-3 hours to obtain carbon powder, adding the cattail into the reaction kettle, adding sodium hydroxide solution and reacting at 150-180degrees Celsius for 10-15 hours, washing, obtaining the cellulose of pupa leaves, adding the cellulose of pupa leaves into the container, adding water and carbon powder, stirring, and filtering, and obtaining a papyrus-based photothermal film, which is a papyrus-based photothermal interface evaporation material. USE - The method for preparing papyrus-based photothermal interface evaporation material useful in seawater desalination and sewage treatment (claimed). ADVANTAGE - The method improves the efficiency of steaming water and the ability to block salt, compares with other solar light absorbers e.g. graphene, and the inexpensive papyrus-based photothermal interface conversion material is easier to meet the application of seawater desalination in real life. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for papyrus-based photothermal interface evaporation material.