Three-dimensional Insight on Formation and Light-harvesting of Hollow-structure Carbon Nitride

Designing nanoarchitectures of graphitic carbon nitride (g-CN) has been considered an effective approach to improve the photocatalytic performance, while a comprehensive understanding for the formation and the light-harvesting enhancement of fashionable hollow-structure g-CNs is lacking. Herein, electron tomography is applied to thoroughly elucidate the evolution from the rod-like melamine-cyanuric acid (MC) complex to hollow-structure g-CN in the supramolecular preorganization synthesis. Three-dimensional characterizations on this evolution unambiguously reveal that the formation of the hollow-structure is determined by the differentiated polymerization condensation between the inner region and the edges of the rod-like MC complex, ascribing to its loose interior and dense surfaces. The simulated electromagnetic field distribution of the obtained hollow-structure g-CN further indicates that nanoscale cavities/pores within the shell and coupling gaps of the inner architecture constitute abundant "hotspots" for amplifying the incident electromagnetic field and thereby for enhancing the light-harvesting and contributing to the performance improvement in photocatalysis.