Constructing Multi‐Interfaced and Vacancy‐Rich Cu_1.8S/rGO/Oleylamine Composites Toward Anti‐Biofouling Microwave Absorption

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_1.8S/reduced graphene oxide/oleylamine (Cu_1.8S/rGO/OLAM) composite integrated with outstanding anti-biofouling properties. Cu_1.8S nanoparticles and OLAM films are sequentially generated on rGO by a one-pot solution-phase thermal decomposition method. The copper vacancy defects in Cu_1.8S 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_1.8S 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_1.8S/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_1.8S/rGO/OLAM composite also shows outstanding anti-biofouling performance with survival rates of bacteria and algae as low as 4% and 35%, respectively.