Enhancement of photocatalytic by Mn3O4 spinel ferrite decorated graphene oxide nanocomposites

The hydrothermal process was used to prepare -Mn3O4/x%GO nanocomposites (NC's) having different ratios of the -Mn3O4 nanoparticles (NP's) on the surface of graphene oxide (GO) sheet. SEM image showed that the -Mn3O4 NP's were distributed over the surface of GO sheet. HRTEM images exhibited the lattice fringe arising from the (101) plane of the -Mn3O4 NP's having the interplanar d-spacing of 0.49 nm decorating on the surface of GO. The electronic absorption spectra of -Mn3O4/x%GO NC's also show broad bands from 250 to 550 nm. These bands arise from the d-d crystal field transitions of the tetrahedral -Mn3+ species and indicate a distortion in the crystal structure. Photo-catalytic activity of spinel ferrite -Mn3O4 NP's by themselves was low but photo-catalytic activity is enhanced when the NP's are decorating the GO sheet. Moreover, the -Mn3O4/10%GO NC's showed the best photo-catalytic activity. This result comes from the formation of Mn-O-C bond that confirm by FT-IR. This bond would facilitate the transfer of the photoelectrons from the surfaces of the NP's to the GO sheets. PL emission which is in the violet-red luminescent region shows the creation of defects in the fabricated -Mn3O4 NP's nanostructures. These defects create the defect states to which electrons in the VB can be excited to when the CB. The best degradation efficiency was achieved by the -Mn3O4 NP's when they were used to decorate the GO sheets in the -Mn3O4/10%GO NC's solution.

Automated summary

The hydrothermal process was used to prepare -Mn3O4/x%GO nanocomposites with different ratios of -Mn3O4 nanoparticles on the surface of graphene oxide sheet. The electronic absorption spectra showed broad bands from 250 to 550 nm, indicating crystal structure distortion. The best photo-catalytic activity was observed in the -Mn3O4/10%GO nanocomposites due to the formation of Mn-O-C bond and enhanced transfer of photoelectrons.