Synthesis of Tailored Carbon Nitride Material Using Polycyclic Aromatic Systems

Graphitic carbon nitrides (g-CN) are one of the synthetic polymers with high physicochemical stability, distinctive optical properties and an attractive electronic structure. g-CN features allow its direct use as a metal-free polymeric semiconductor in various fields such as photocatalysis, solar cell, heterogeneous catalysis, and other energy-related applications. However, their relative wide band gap limits their visible light harvesting and their activity in solar related fields. So far, various strategies have been devoted to modulate their light absorption towards the visible region and for enhancing the photo-induced charge carrier separation. Herein our strategy is to design and synthesize highly efficient g-CN-based materials by molecular engineering. The idea of designing polycyclic aromatic system allows modification of preferred materials and intensifies the conjugate effect. In this work, we have introduced various aromatic rings in the carbon nitride framework to extend π-conjugation for visible light harvesting and also to improve the charge transfer efficiency. The aromatic-modified materials give the π-π stacking configuration which is basically narrow the band gap and enhance the utilization of photo-induced electrons. This work provides a new approach to increase optical absorption, electronic properties and optimized band arrangements to advance the various applications of functionalized carbon nitrides.