| Full text | |
| Author(s): |
Damasceno, Joao Paulo Vita
;
Kubota, Lauro Tatsuo
Total Authors: 2
|
| Document type: | Journal article |
| Source: | ANGEWANDTE CHEMIE-INTERNATIONAL EDITION; v. 61, n. 12, p. 6-pg., 2022-11-23. |
| Abstract | |
Herein we have proposed that a redox mechanism can produce surface charges and negative zeta potential on an aqueous graphite dispersion. Graphite was kept in contact with a concentrated ammonia aqueous solution, washed, and exfoliated in water, resulting in a dispersion with lyophobic nature. Ammonia treatment did not provide functional groups or nitrogen doping to graphite. Moreover, this material was washed twice before sonication to remove most hydroxide. Therefore, neither functional groups, nitrogen atoms, nor hydroxide excess is responsible for the zeta potential. Kelvin probe force microscopy has shown that the ammonia-treated and exfoliated graphite has higher Fermi level than the water-treated material, indicating that the contact between ammonia and graphite promotes redox reactions that provide electrons to graphite. These electrons raise the Fermi level of graphite and generate the negative zeta potential, consequently, they account for the colloidal stability. (AU) | |
| FAPESP's process: | 13/22127-2 - Development of novel materials strategic for integrated analytical devices |
| Grantee: | Lauro Tatsuo Kubota |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 20/06604-9 - Conductive inks based on carbon nanomaterials for the preparation of electrodes applied to electrochemical devices |
| Grantee: | João Paulo Vita Damasceno |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis |
| Grantee: | Marco Aurelio Zezzi Arruda |
| Support Opportunities: | Research Projects - Thematic Grants |