Synthesis and modification of black phosphorus for use in tribology

Black phosphorus (BP), a material known for its use in electronics, has emerged among recent studies for its potential in tribology as a solid lubricant. This thesis investigates if the tribological potential of BP can be further expanded upon through alternate syntheses and modifications thereof. Results of these investigations demonstrate that black phosphorus produced using cheaper synthetic methods (solvothermal and mechanochemically) may provide superior tribological properties to that of black phosphorus produced by chemical vapour transport (CVT). Particularly mechanochemically synthesized BP shows exceptional tribological properties, achieving coefficients of friction comparable to that of costly CVT-BP, highlighting its industrial potential as a low-cost solid lubricant. Furthermore, intercalated BP materials (e.g., BP/LiF, BP/KF) and fluorinated BP were synthesised. Some of these new BP materials show remarkably low coefficient of friction (COF), suggesting new lubricants for chemically inert (H2, NH3) and/or fluorinated atmospheres, as well as environments under vacuum. Finally, preliminary tribological results were obtained on novel BP composite materials containing bismuth, gallium or boric acid, some with promising COF values.