Gamma rays assisted synthesis of N doped-graphene quantum dots from multiwall carbon nanotubes

Abstract

Gamma rays are the powerful tool for top-down synthesis of nitrogen doped graphene quantum dots (NGQDs) from multiwall carbon nanotubes. Different doses of gamma rays (100, 200 and 300 kGy) were applied to the multiwall carbon nanotubes suspended in mixture of sulfuric and nitric acid (3:1 ratio). After purification, NGQD were characterized to investigate their structure (morphology, particle size, nanomechanical and nanoelectrical properties, chemical composition, photoluminescence, reactive oxygen species production, antibacterial activity and biocompatibility). Viscoelastic measurements revealed that NGQDs nanoparticles had Young’ modulus of elasticity almost equal to single wall carbon nanotubes (SWCNTs (6,5)). Electrostatic force and scanning tunneling microscopy showed that all types of the NGQDs nanoparticles had negative charge distributed homogeneously. All NGQDs samples produced singlet oxygen and the NGQDs300 sample showed moderate antibacterial activity and good biocompatibility