Affiliation:
1. Univ. Bordeaux CNRS CRPP UMR 5031 Pessac 33600 France
2. Carbon Waters 14 avenue Pey Berland Pessac 33600 France
3. Université de Bordeaux CNRS PLACAMAT UAR 3626 Pessac F‐33600 France
4. Institut de Ciència de Materials de Barcelona (ICMAB‐CSIC) Campus de la UAB Bellaterra E‐08173 Spain
Abstract
AbstractGraphene in water is electrically charged in most conditions. The level of charge can be large enough to stabilize single (or few) layer graphene colloidal dispersions in water, without the need of using any other additive. In this work, potentiometric titration, isothermal titration calorimetry, electrokinetic measurements, Density Functional Theory calculations, Raman Spectroscopy, and direct force measurements using Atomic Force Microscopy to investigate this charge and explore its origin are combined. The body of data collected suggests that this charge is a consequence of the interaction between water ions (hydroxide and hydronium) and graphene, and can be conveniently tuned (in magnitude and sign) by changing the pH of water.
Funder
Association Nationale de la Recherche et de la Technologie
Agence Nationale de la Recherche