Authors: Alhaddad, M; Navarro, RM; Hussein, MA; Mohamed, RM Article. Nanosci. Nanotechnol. Lett.. vol: 12. page: 1941-4900. Date: MAR. 2020. Doi: 10.1166/nnl.2020.3106. Abstract: In this paper, we introduce an active photocatalyst for hydrogen generation from aqueous glycerol solution on nanoheterojunctions of graphitic carbon nitride (g-C3N4) and Co3O4 at various Co3O4 loading (1 similar to 4 wt.%). The Co3O4 nanoparticulates were efficiently spread on the exterior of exfoliated mesoporous g-C3N4 by means of ultrasonication-mixture method that allowed the formation of effective Co3O4/g-C3N4 heterojunctions that minimized high recombination of charges observed on bare g-C3N4. The formation of nanoheterojunctions amid Co3O4 and g-C3N4 was demonstrated by XPS and HRTEM. Moreover, their number and efficiency in separation of charges depended on Co3O4 loading (maximum efficiency at 3 mol% of Co3O4). The optimal Co3O4/g-C3N4 nanocomposite demonstrated 22.5 and 33.7 times higher H-2 production using visible light compared to the parent g-C3N4 and Co3O4 systems, respectively. The differences in photocatalytic action for the Co3O4/g-C3N4 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..