A concise review of recent advances in carbon nitride-based intramolecular donor–acceptor architectures for photocatalytic hydrogen production: Heteromolecular coupling of organic compounds

This paper aims to provide a concise and focused review of the utilization of artificial donor–acceptor (D/A) conjugated systems based on graphitic carbon nitrides (g–CN) in relation to renewable energy and environmental applications. The review emphasizes the critical role played by charge transfer processes between D/A moieties, which significantly accelerate the injection of photoelectrons into the conduction band of g–CN-based semiconducting materials. Notably, the manipulation of energy levels and electron affinities within these systems exerts a profound influence on bandgap and electronic mobility, thereby resulting in modified compounds with superior properties. By specifically focusing on intramolecular D/A structures utilized for photocatalytic H ₂ production, this review redresses the current dearth of comprehensive scrutiny in this specialized domain. Additionally, the review elucidates the underlying principles governing electron donor–acceptor chemistry, while providing in-depth insights into the fabrication techniques employed for g–CN-based D/A configurations. Finally, it culminates in a concise summary of the most noteworthy studies concerning intramolecular donor–acceptor g–CN copolymeric materials employed in photocatalytic H ₂ evolution. This comprehensive analysis aims to provide scholars with a broader and more nuanced perspective, ultimately fostering the design and development of novel and innovative g–CN-based photocatalysts.