Carbon Nitrides from Supramolecular Crystals: From Single Atoms to Heterojunctions and Advanced Photoelectrodes

Carbon nitride materials (CN) have become one of the most studied photocatalysts within the last 15 years. While CN absorbs visible light, its low porosity and fast electron-hole recombination hinder its photoelectric performance and have motivated the research in the modification of its physical and chemical properties (such as energy band structure, porosity, or chemical composition) by different means. In this Concept we review the utilization of supramolecular crystals as CN precursors to tailor its properties. We elaborate on the features needed in a supramolecular crystal to serve as CN precursor, we delve on the influence of metal-free crystals in the morphology and porosity of the resulting materials and then discuss the formation of single atoms and heterojunctions when employing a metal-organic crystal. We finally discuss the performance of CN photoanodes derived from crystals and highlight the current standing challenges in the field. Supramolecular single crystals based on C-N monomers are used to prepared carbon nitride materials with tailored morphology and porosity, single atom catalysts or heterojunctions. This approach can be applied to fabricate efficient water splitting photoelectrodes.image

Automated summary

Carbon nitride materials (CN) are widely studied photocatalysts, but their low porosity and fast electron-hole recombination limit their photoelectric performance. This article reviews the use of supramolecular crystals as precursors for CN, discussing their influence on morphology and porosity, and the formation of single atoms and heterojunctions when using metal-organic crystals. The performance of CN photoanodes derived from crystals and the current challenges in the field are also discussed.