Rigid-flexible NiFe-LDH/MoS2 nanocomposite enables fast adsorption and high-load lubrication in oils

High-performance lubricants are vital for industrial machinery operating under extreme loads and temperatures, yet conventional additives often fail to meet modern industrial demands due to limited tribological performance. This study reports an oleylamine-modified nickel-iron layered double hydroxide-molybdenum disulfide (OA-NiFe-LDH/MoS 2 ) nanocomposite, synthesized under mild conditions via in-situ surface modification in a one-pot liquid-phase route. The rigid NiFe-LDH lamellae provide abundant adsorption sites and cooperate with the low-shear-stress characteristic of flexible MoS 2 nanosheets to enable fast adsorption and high-load lubrication. Anti-wear and friction-reduction of the nanocomposite in poly-α-olefin-6 (PAO6) base oil were evaluated on a four-ball friction tester. Parallel tests on pristine OA-MoS 2 nanoparticles were conducted to isolate the contribution of the LDH component. At 75°C and 392 N, coefficient of friction (COF) decreased by 36 % to 0.066, with exceptional anti-wear performance maintained at 150°C, significantly outperforming neat PAO6 and OA-MoS 2 alone in steel-steel contacts. Spectroscopic and thermal analyses demonstrate superior dispersibility, while surface characterization reveals that the nanocomposite promotes extensive tribochemical formation of sulfides and oxides, forming a durable transfer film that minimizes metal contact and wear. Synergistic interplay between adsorption capacity of NiFe-LDH and lubricity of MoS 2 enables robust physical and chemisorbed films, ensuring stability under extreme conditions. Thermal stability and oxidation resistance of the nanocomposite mitigate lubricant degradation, offering a promising strategy for designing energy-efficient, durable lubricants for high-load, high-temperature industrial applications, with substantial potential to lower operational costs and environmental impact.