2D/3D-C3N4/CeO2 S-scheme heterojunctions with enhanced photocatalytic performance

A facile, green and easily scalable method has been developed to facilitate the construction of 2D-C3N4/3D-CeO2 heterojunction materials. It uses only cheap urea and ceria in a thermal spreading technique that allows the controlled growth of carbon nitride layers on cerium oxide surface. The exfoliation of bulk carbon nitride and subsequent stabilization of layers on ceria takes place during thermal spreading technique in a single step. Simple variation of carbon nitride allowed to control the morphology of carbon nitride from highly dispersed thin layer up to bulk-like structures over ceria surface. The optical absorption was enhanced with 2D-C3N4/3D-CeO2 materials. The variation of structure and consequent differences in the solar powered decomposition of methylene blue has been analyzed. Results reveal that, the optimum loading of 7.5 wt% carbon nitride can lead to the formation of intermediate structure in between very thin layers and bulk-like structure, that achieves best contact between the two phases making effective heterojuctions. This best catalyst exhibits 98 % conversion at a timing of 100 min. The radical scavenging studies showed that center dot O2- and h + performed an imperative role. In addition, a plausible mechanism of photo catalytic decomposition is also proposed for 2D-C3N4/3D-CeO2 materials.

Automated summary

A facile, green and easily scalable method has been developed for constructing 2D-C3N4/3D-CeO2 heterojunction materials using cheap urea and ceria. The controlled growth of carbon nitride layers on cerium oxide surface was achieved through a thermal spreading technique. The morphology of the carbon nitride could be controlled by varying its composition. The optical absorption and catalytic activity of the materials were enhanced, and a plausible mechanism for the photocatalytic decomposition was proposed.