Tailoring the edge defects and morphology of g-C3N4 for efficient CO2 conversion to cyclic carbonates

This research endeavors to optimize the morphology and edge defects of g-C 3 N 4 through straightforward pyrolysis of rationally chosen precursors, with the objective of increasing the CO 2 conversion efficiency. Our findings reveal that employing melamine and urea as precursors yields tubular g-C 3 N 4 (CN tube), featuring an increased surface area and a greater density of edge defects than melamine-derived bulk g-C 3 N 4 and urea-derived layered g-C 3 N 4 . As a result, the obtained CN tube can deliver an impressive yield of 98 % for CO 2 cycloaddition with epichlorohydrin at 12 h under mild conditions of 80 °C and 0.1 MPa CO 2 pressure, significantly outperforming those derived from melamine (53 %) or urea (66 %) alone. This investigation demonstrated the pivotal role of a tubular architecture and enriched edge defects in facilitating the thermally driven CO 2 fixation process to produce cyclic carbonates.