Influence of integrated nitrogen functionalities in nitrogen doped graphene modified WO3 functional visible photocatalyst

Nitrogen doped graphene modified WO3 nanocomposites were synthesized through an effective methodology. The prepared photocatalysts were employed as active candidates for degradation of highly toxic organics i.e., 2, 4 dichloro phenol (2, 4-DCP) and methyl orange (MO). XRD profile of N-graphene showed complete reduction of GO into N-graphene. All diffraction peaks of WO3 along with N-graphene indicated monoclinic phase of WO3. SEM and TEM images of 3.0% N-graphene/WO3 have demonstrated the mixed morphology of irregular massive rod like blocks and round shaped particles of WO3 distributed on cracked sheets of N-graphene. Nitrogen defects in graphene altered zero band gap semi-metallic graphene to semiconducting material and increased the absorption edge of N-graphene/WO3 nanocomposites towards visible region as studied in DRS analysis. FTIR and Raman studies showed the strong connection between N-graphene and WO3 by making W−O−C surface linkage. The noticeable reduction in PL emission peaks of 3.0% N-graphene/WO3 indicated obvious separation of photo induced charge carriers. The study of radical scavengers suggested that holes (h+) and •OH are the main elements for the decontamination of both MO and 2, 4-DCP. XPS analysis shows all possible C−N bonding configurations in 3.0% N-graphene/WO3. 3.0% N-graphene/WO3 composite showed the maximum photo degradation of MO (~94.0%) and 2, 4-DCP (~81.0%). The synergism between N-graphene and WO3 results into more sporty sites on catalyst and restoring of sp2 structural defects in N-graphene lattice improve the transportation of charge carriers during photocatalysis. This work provides innovative strategies for designing the N-graphene/semiconductor nanosystems with enhanced photocatalytic phenomena in the environmental cleanup remedies.