Spin polarized density functional theory has been used to investigate energetics and electronic properties that BC2N nanostructures (tubes and layers) exhibit after fluorine is adsorbed. The calculated adsorption energies show that fluorine atoms are exothermically and preferentially adsorbed on top of boron atoms. The electronic properties show that fluorinated nanostructures can exhibit acceptor properties or deep electronic levels inside the band gap, depending on whether the fluorine atoms are adsorbed on top of boron or carbon atoms. In addition, we observe that fluorinated nanostructures have non-zero spin magnetic moments. (C) 2013 Elsevier B. V. All rights reserved.