RESUMO
0D/2D heterojunctions, especially quantum dots (QDs)/nanosheets (NSs) have attracted significant attention for use of photoexcited electrons/holes due to their high charge mobility. Herein, unprecedent heterojunctions of vanadate (AgVO3 , BiVO4 , InVO4 and CuV2 O6 ) QDs/graphitic carbon nitride (g-C3 N4 ) NSs exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed. The photoactive contribution, up-conversion absorption, and nitrogen coordinating sites of g-C3 N4 NSs, highly dispersed vanadate nanocrystals, as well as the strong coupling and band alignment between them lead to superior visible-light-driven photoelectrochemical (PEC) and photocatalytic performance, competing with the best reported photocatalysts. This work is expected to provide a new concept to construct multifunctional 0D/2D nanocomposites for a large variety of opto-electronic applications, not limited in photocatalysis.
RESUMO
Our TEM observation revealed that in a carbon-Pt3Co system, amorphous carbon first crystallized into nanoclusters at step-edges on melting Pt3Co surfaces before merging into graphene layers through a kinetic restructuring via oriented-attachment, leading to the final formation of few-layered graphene nanostructures. The result obtained from density-functional theory calculations further suggested that Co atoms rather than Pt atoms acted as initial nucleation centers.