Constructing Multi‐Interfaced and Vacancy‐Rich Cu1.8S/rGO/Oleylamine Composites Toward Anti‐Biofouling Microwave Absorption

Abstract Anti‐biofouling performance plays a critical role for marine application of microwave absorption materials (MAMs) to maintain their stable and durable absorption capacity. However, anti‐biofouling properties are generally ignored by traditional MAMs that merely pursue strong microwave absorption (MA) capability. Herein, this work reports for the first time the preparation of ternary Cu 1.8 S/reduced graphene oxide/oleylamine (Cu 1.8 S/rGO/OLAM) composite integrated with outstanding anti‐biofouling properties. Cu 1.8 S nanoparticles and OLAM films are sequentially generated on rGO by a one‐pot solution‐phase thermal decomposition method. The copper vacancy defects in Cu 1.8 S can effectively induce dipole polarization. The surface‐coated OLAM layers can not only provide abundant heterogeneous interfaces to induce interfacial polarization, but also improve the hydrophobicity to reduce organism adhesion. Cu 1.8 S can also release copper ions that damage bacterial and algal cell membranes and induce protein denaturation, contributing to enhancement of anti‐biofouling properties. rGO with high conductive loss and a sharp edge can both improve MA and anti‐biofouling properties. Consequently, the Cu 1.8 S/rGO/OLAM composite exhibits a remarkable MA capability, with a minimum reflection loss value of −56.2 dB and an effective absorption bandwidth of 9.68 GHz. Additionally, Cu 1.8 S/rGO/OLAM composite also shows outstanding anti‐biofouling performance with survival rates of bacteria and algae as low as 4% and 35%, respectively.