Transformation of C-14-Labeled Graphene to (CO2)-C-14 in the Shoots of a Rice Plant

摘要

This study focused on using carbon-14-labeled few-layer graphene (FLG) to determine its uptake, distribution, transformation, and depuration in rice plants. After 7d hydroponic exposure to FLG suspension at 250gL(-1), roots accumulated 694.8mgkg(-1) graphene and shoots had 53.7mgkg(-1) graphene from intra-plant translocation. FLG could likely pass through the cell wall and membrane and enter the chloroplast in the shoots. After 14 days of depuration, only about 15% of the accumulated FLG were eliminated into the depuration solution with about 70% of graphene retained in the plants. About 9% of the accumulated FLG was degraded to (CO2)-C-14 and proposed that reaction with OH. in the leaves may likely contribute to the degradation of FLG, which had structural defects. These findings have an important impact on the long-term environmental fate of graphene-related materials in soil-plant systems.