Aqueous dispersion of n-doped graphite and the electronic stabilization of lyophobic colloids

An aqueous dispersion of non-passivated graphite was prepared starting with a treatment based on concentrated ammonia solution, which transfers electrons to graphite and produces a slightly n-doped material. The electronic doping was probed by ultraviolet photoelectron spectroscopy and Kelvin probe force microscopy. This n-doping remains on graphite particles after washing and exfoliation and is responsible for the negative zeta potential and colloidal stability of the exfoliated graphite particles. A theoretical model was developed to describe the surface and zeta potentials in terms of the electronic structure of graphite, corroborating that electronic doping can provide colloidal stabilization. Potentiometry demonstrated the change in the electrochemical potential of the solution containing the aqueous graphite dispersion in relation to samples without it or containing undoped particles, highlighting the possibility of using this dispersion as an electron reservoir for further electrochemical reactions.