Simulation of geological graphene genesis by the piston-cylinder apparatus

Autor: Augusto Gonçalves Nobre, Andrés Fabián Salazar-Naranjo, Fabio Ramos Dias de Andrade, Silvio Roberto Farias Vlach, Rômulo Augusto Ando
Rok vydání: 2022
Předmět:
Zdroj: Matéria (Rio de Janeiro) v.27 n.4 2022
Matéria (Rio de Janeiro. Online)
instacron:RLAM
Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
ISSN: 1517-7076
DOI: 10.1590/1517-7076-rmat-2022-0122
Popis: Stable natural graphene occurs in graphite- and phyllosilicate-bearing low-grade metamorphic rocks. The present work simulates the process of geological formation of graphene using a piston-cylinder apparatus, promoting diffusion between talc and graphite at 700ºC and 900 MPa for a period of 24 h. The experimental products were analyzed by optical and scanning electron microscopy for description of the microstructures formed between the mineral precursors. The talc-graphite diffusion zone was also analyzed by Raman spectroscopy. Results indicate that graphite becomes progressively more deformed near the talc diffusion zone and eventually undergoes cleavage. Graphene becomes stable on the talc substrate in the center of diffusion zone. Therefore, the search for deposits of natural graphene and other nanomaterials in geological context is promising.
Databáze: OpenAIRE