Al2O3/reduced graphene oxide double-layer radiative coating for efficient heat dissipation

Highlights: • A novel Al₂O₃/reduced graphene oxide double-layer radiative coating was designed for efficient heat dissipation. • The double-layer coating was fabricated by assembling reduced graphene oxide on Al₂O₃ bottom layer. • The high emissivity double-layer coating enabled a significant LED temperature drop. • The duplex coating showed superior hydrophobic and anti-corrosion properties. In this work, a double-layer radiative coating was designed, and its radiative heat dissipation performance was studied theoretically and experimentally. The duplex coating was fabricated by assembling reduced graphene oxide (rGO) on Al₂O₃ bottom layer. The effects of Al₂O₃/rGO coatings on thermal radiation, heat dissipation and anti-corrosion properties of light emitting diode (LED) were investigated. The Al₂O₃/rGO radiative coating promoted the infrared emissivity value from 0.1 (bare aluminum radiator) to 0.57 at 3–8 μm and 0.83 at 8–20 μm waveband range, respectively. The double-layer coated aluminum alloy with high emissivity value enabled a significant 1 W LED temperature drop by 5.6 °C, which was coincident with the result by simulation (1 W). More remarkable, the temperature drop further decreases to 14.0 °C for 5 W LED chip. In addition, the Al₂O₃/rGO duplex coating exhibited superior hydrophobic and anti-corrosion properties, which is expected to be a promising candidate for heat dissipation of electronic products serving in oceans and humid ambient.