Production of Stable Pickering Emulsions Stabilized by Concentrated Sols of Carbon Nitride and Graphene Oxide

This study introduces a novel method for producing stable, highly concentrated Pickering emulsions in a water/n-hexane system, stabilized by 2D carbon nitride (g-CN) particles and their hybrid dispersions with graphene oxide (GO). The approach leverages electrostatic interactions induced by zinc acetate (Zn(OAc)). Sedimentation stability analysis and optical microscopy identified optimal conditions for emulsions with g-CN concentrations up to 6 mg/mL. Fluorescence microscopy with fluorescein confirmed oil-in-water (o/w) emulsion formation, stabilized by either g-CN alone or GO/g-CN binary dispersions. Zeta potential measurements of g-CN sols and emulsions revealed the stabilization mechanism: acetate ions (CHCOO) drive negatively charged g-CN particles from the aqueous phase to the interface, while zinc cations (Zn) adsorb onto g-CN surfaces, suppressing particle repulsion within droplet shells. For GO/g-CN hybrids, Zn further stabilizes emulsions via coordination bonds between GO carboxyl groups and g-CN, ensuring particle integration and preventing phase separation. The findings offer a labile platform for designing tunable photocatalytic systems for organic pollutant degradation and functional material synthesis.