Carbon fiber (CF) has been widely used in aerospace, military, infrastructure, sports, and leisure fields owing to its excellent mechanical properties, superior corrosion and friction resistances, excellent thermal stability, and lightweight. However, the ultrablack appearance derived from the extremely strong absorption of light throughout the entire visible region makes it difficult to satisfy the aesthetic and pleasurable demands of the colorful world and limits their applications in a broader field. Herein, inspired by the Japanese jewel beetle, a double-layer ultrathin Al2O3/TiO2 composite structure was fabricated on CFs by the atomic layer deposition method. CFs exhibited desired color diversity by controlling the thickness of Al2O3 and TiO2 films without changing the total thickness of the composite film's structure. Meanwhile, colored CFs have no color change/destruction after a series of environmental durability measurements and exhibited remarkable superdurability and excellent flame retardancy. Our work provides insights for innovative, high-performance, and multifunctional CF that can help achieve high quality and sustainable development of the CF industry.
Keywords: carbon fibers; double-layer film; excellent color fastness; flame retardant; structural color.