Co3O4/g-C3N4 Nanocomposites Prepared via Ultrasonication as Active Photocatalyst for H2 Generation Beneath Visible Light

In this paper, we introduce an active photocatalyst for hydrogen generation from aqueous glycerol solution on nanoheterojunctions of graphitic carbon nitride (g-C 3 N 4 ) and Co 3 O 4 at various Co 3 O 4 loading (1∼4 wt.%). The Co 3 O 4 nanoparticulates were efficiently spread on the exterior of exfoliated mesoporous g-C 3 N 4 by means of ultrasonication-mixture method that allowed the formation of effective Co 3 O 4 /g-C 3 N 4 heterojunctions that minimized high recombination of charges observed on bare g-C 3 N 4 . The formation of nanoheterojunctions amid Co 3 O 4 and g-C 3 N 4 was demonstrated by XPS and HRTEM. Moreover, their number and efficiency in separation of charges depended on Co 3 O 4 loading (maximum efficiency at 3 mol% of Co 3 O 4 ). The optimal Co 3 O 4 /g-C 3 N 4 nanocomposite demonstrated 22.5 and 33.7 times higher H 2 production using visible light compared to the parent g-C 3 N 4 and Co 3 O 4 systems, respectively. The differences in photocatalytic action for the Co 3 O 4 /g-C 3 N 4 composites was examined in terms of changes in their capacity to engross the light and to diminution the electron-hole recombination associated with different development of nanoheterojunctions in the composites.