Effect of Structural Defects on Electrical Conductivity of Graphitic Biocarbon

The catalytic graphitization process is considered a promising method for producing well-structured advanced biocarbon with a higher degree of graphitization at lower temperatures. The challenge with advanced biocarbon materials lies in determining their properties and expanding their applications beyond standard uses in soil, the environment, and fuel to more advanced areas, such as composites, electronics, photonics, and energy storage. Data on their properties remains scarce. This study examines the nanostructure chemistry of graphitic biocarbon produced through the catalytic graphitization of cellulose at various temperatures, accompanied by a comprehensive investigation of defects. The new approach developed uses the iron-calcium bimetallic catalytic graphitization. The conductive grains of graphitic biocarbon become active, improving the electrical conductivity to approximately 10^-2 S m^-1, which strongly depends on defects from grain boundaries and vacancies. Furthermore, the conductive capacity of biocarbon is enhanced by an increase in graphitic sp² carbon content and a decrease in defect concentration, such as carbon vacancy defects, which decline from 11.77% to 6.57% between 1200 and 1800 °C. Herein, we assert that high-temperature catalytic graphitization generates defective graphitic biocarbon, and these defects significantly influence its properties, establishing it as a potential semiconductive material that expands its applications in photonics and electro-optics, thus opening new opportunities.