Photochemical processes developed in composites based on MoS2, poly(ortho-toluidine), and reduced graphene oxide

Abstract

Using solid-state interactions, composites based on molybdenum disulfide (MoS₂), poly(ortho-toluidine) (POT), and reduced graphene oxide (RGO) were prepared. Raman scattering and FTIR spectroscopic studies have demonstrated that the interaction of the RGO and MoS₂ sheets with the POT-emeraldine base state (EB) leads to composites composed of RGO sheets non-covalently functionalized with pseudo-protonic POT doped with MoS₂ and RGO covalently functionalized with POT-leucoemeraldine salt (LS). An alternative way to prepare these composites is the solid-state interaction of the RGO and MoS₂ sheets with the POT-emeraldine salt (ES), resulting in composites composed of RGO non-covalently functionalized with POT-salt having pseudo-protonic acidic entities doped with MoS₂ and RGO covalently functionalized with POT-leucoemeraldine base (LB). Using UV-Vis spectroscopy, we demonstrate that the exposure of these composites to UV light in protic polar solvents leads to the generation of partially de-doped POT-LB and POT-ES. The features of the composites after light exposure, as well as their transformation to the salt state, are highlighted by surface-enhanced Raman scattering. This study contributes to better understanding of the properties of the composites based on MoS₂, POT, and RGO, highlighting the need to avoid the exposure of composites dissolved in polar protic solvents to UV light.