The true liquid crystal phases of 2D polymeric carbon nitride and macroscopic assembled fibers

The fluids of fascinating nanomaterials have recently been reported to exhibit liquid crystalline (LC) phases, and these mesophases have attracted significant interest in both fluid physics and cutting-edge applications; graphitic carbon nitride (g-CN), a type of 2D semiconducting polymers, has gained significant attention in recent years for optoelectronic and catalytic applications. However, g-CN has been studied on a powder material, which suffers from limited dispersibility, difficult recovery, and low surface accessibility. In this study, we report that controlled g-CN, which has high-aspect ratio and expanded interlayer spacing, can exhibit its true LC phase in concentrated sulfuric acid. By utilizing its LC phase, more importantly, we could fabricate a g-CN fiber for the first time.