Codoped stacked nanosheets for simultaneous atomic oxygen and electrostatic discharge protection in space environments

Abstract

Layered double hydroxides (LDHs) have garnered considerable attention owing to their unique layered structure. Recently, the excellent barrier effect of stacking LDH nanosheets has been found and demonstrated great potential for atomic oxygen (AO) protection in low Earth orbit (LEO) where space stations and Starlink satellites operate. However, the inherent wide bandgap and the resulting highly insulating nature of LDHs make them vulnerable to electrostatic discharge (ESD), posing a critical challenge for space applications. Here, we proposed to codope (Mg,Al)-LDHs with sulfur and nickel to prepare conductive LDHs and satisfy the requirement for both ESD and AO protection. By coating the doped-LDHs on polyimide film, we achieve layered structure formed by interlaced LDH nanoflakes. The sheet resistance is reduced by four orders of magnitude compared with unmodified LDHs. More importantly, the coated polyimide film exhibits simultaneous protections against ESD (sheet resistance of 5.77 × 10⁸ Ω/sq well below the necessary of 10¹⁰ Ω/sq) and atomic oxygen (weight gain was about 7.40 mg/cm² under 4.35 × 10²⁰ atoms/cm² of AO influence and 50 ESH of UV radiation). Unlike conventional strategies that mitigate AO erosion by increasing material density, this approach leverages the adsorption properties of LDHs. Doping enhances the capacity of LDHs to adsorb AO, offering a novel strategy for space environment protection.