Multifunctional graphene and graphene-MoS₂ coatings via electrophoretic deposition: morphological, electrical, and thermal characterization
摘要
This study investigates the application of graphene-based coatings deposited via cathodic electrophoretic deposition (EPD) onto various substrates, including copper foil, fluorine-doped tin oxide (FTO), and stainless-steel mesh. The influence of key process parameters—such as deposition time and substrate type—on the morphology, thickness, surface roughness, adhesion, thermal conductivity, and electrical resistivity of the graphene films is examined. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are employed to characterize surface topography and cross-sectional morphology. A strong correlation is observed between AFM and SEM measurements in estimating the deposited graphene thickness, with increased film thickness corresponding to reduced surface roughness. Adhesion tests reveal that thicker coatings adversely affect film adherence. Specifically, the graphene coating on the stainless-steel mesh led to substantial enhancements in both thermal and electrical properties: the thermal conductivity increased from 14.62 W·m⁻¹·K⁻¹ (non-coated mesh) to 65.00 W·m⁻¹·K⁻¹, while the electrical resistivity decreased from 20.0 × 10⁻⁷ to 4.20 × 10⁻⁷ Ω·m. These improvements were achieved with a graphene layer thickness of 110 μm. Additionally, the co-deposition of graphene and molybdenum disulfide (MoS₂) on copper and stainless-steel mesh substrates via EPD was successfully achieved, demonstrating uniform dispersion and promising multifunctional properties, the thermal conductivity increased to 37.38 W·m⁻¹·K⁻¹ and the electrical resistivity decreased to 8.51 × 10⁻4 Ω·m by co-depositing graphene-MoS₂ for 140 μm on the stainless-steel mesh. These findings underscore the scalability and effectiveness of the EPD technique for fabricating high-performance graphene-based coatings on both flat and porous substrates, with significant potential in energy, electronics, and sensing applications.
Graphical Abstract