摘要:AbstractPreparation of superhydrophobic carbon materials from lignocellulosic biomass waste via one‐step carbonization is very difficult due to the existences of polar functional groups and ashes, which are extremely hydrophilic. Herein, superhydrophobic carbon materials can be facilely synthesized by catalytic pyrolysis of biomass waste using FeCl3as catalyst. The results show that the surface energy of lignin‐derived char (CharL) is significantly reduced to 19.25 mN m−1from 73.29 mN m−1, and the water contact angle increased from 0 to 151.5°, by interaction with FeCl3. Multiple characterizations and control experiments demonstrate that FeCl3can catalyze the pyrolytic volatiles to form a rough graphite and diamond‐like carbon layer that isolates the polar functional groups and ashes on CharL, contributing to the superhydrophobicity of the CharL. The one‐step catalytic pyrolysis is able to convert different natural biomass waste (e.g., lignin, cellulose, sawdust, rice husk, maize straw, and pomelo peel) into superhydrophobic carbon materials. This study contributes new information related to the interfacial chemistry during the sustainable utilization of biomass waste.A facile method of converting biomass waste into superhydrophobic carbon materials is proposed by catalytic fast pyrolysis. The mechanism is attributed to the capping of the carbon deposition on the char coupled with the increased roughness, catalyzed by FeCl3. The superhydrophobic biochar exhibits outstanding stability in harsh environments and excellent performance in oil/water separation and self‐cleaning surfaces.