FABRICATION OF STABLE CONCENTRATED PICKERING EMULSIONS BASED ON CARBON NITRIDE AND GRAPHENE OXIDE

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Abstract

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-C3N4) particles and their hybrid dispersions with graphene oxide (GO). The approach leverages electrostatic interactions induced by zinc acetate (Zn(OAc)2). Sedimentation stability analysis and optical microscopy identified optimal conditions for emulsions with g-C3N4 concentrations up to 6 mg/mL. Fluorescence microscopy with fluorescein confirmed oil-in-water (o/w) emulsion formation, stabilized by either g-C3N4 alone or GO/g-C3N4 binary dispersions. Zeta potential measurements of g-C3N4 sols and emulsions revealed the stabilization mechanism: acetate ions (CH3COO–) drive negatively charged g-C3N4 particles from the aqueous phase to the interface, while zinc cations (Zn2+) adsorb onto g-C3N4 surfaces, suppressing particle repulsion within droplet shells. For GO/g-C3N4 hybrids, Zn2+ further stabilizes emulsions via coordination bonds between GO carboxyl groups and g-C3N4, 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.

About the authors

A. I Gorshkova

Lomonosov Moscow State University; Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences

Email: kalinina@phyche.ac.ru
Moscow, Russia; Moscow, Russia

A. G Nugmanova

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences

Email: kalinina@phyche.ac.ru
Moscow, Russia

A. I Zvyagina

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences

Email: kalinina@phyche.ac.ru
Moscow, Russia

E. K Urodkova

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences

Email: kalinina@phyche.ac.ru
Moscow, Russia

A. A Mikhailov

Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences

Email: kalinina@phyche.ac.ru
Moscow, Russia

P. V Prikhodchenko

Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences

Author for correspondence.
Email: kalinina@phyche.ac.ru
Moscow, Russia

M. A Kalinina

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences

Email: kalinina@phyche.ac.ru
Moscow, Russia

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