Intercalation-driven defect-induced charge transport in NiO-incorporated MoS₂ nanoflowers

In this study, MoS₂ nanoflowers, NiO nanoparticles, and MoS₂/NiO were synthesized using a hydrothermal method. XRD analysis confirmed the formation of MoS₂, NiO and the MoS₂/NiO nanocomposite without any indication of a new phase. Raman peak redshift and intensity variation indicate modifications in the local vibrational environment associated with the formation of the MoS₂/NiO heterostructure. FESEM revealed a spherical, flower-like morphology for the three-dimensional structures of both MoS₂ and the MoS₂/NiO nanocomposite. HRTEM and SAED analyses confirm the formation of a MoS₂/NiO heterojunction with intimate interfacial contact and lattice distortion, indicating strong interfacial interactions between the two phases. The electrochemical properties of the nanocomposite were found to be improved due to the incorporation of the NiO nanoparticle into it. The MoS₂/NiO offers a specific capacitance of 1725.50 F g⁻¹ at 1 A g⁻¹, higher than pristine MoS₂ (827.16 F g⁻¹). It exhibited remarkable energy storage capacity and maintained 86% capacitance even after 5000 charge–discharge cycles. Electrochemical impedance spectroscopy showed that the incorporation of NiO nanoparticles reduced the charge transfer resistance, enhancing electronic conductivity, which boosted charge carrier kinetics in the MoS₂/NiO nanocomposite. To evaluate the practical applicability, two-coin cell devices were assembled and connected in series. The fabricated device successfully powered a light-emitting diode (LED) for approximately 180 seconds, clearly demonstrating its promising energy storage capability and potential for real-world applications.