Catalyst-free achieving of controllable carbon doping of boron nitridenanosheets by CO molecules: a theoretical prediction

Abstract

Controllable carbon (C) doping in a boron nitride (BN) nanostructure can render it exciting magnetic and conductive properties, which would be very valuable for its potential applications in optoelectronics and spintronics. Thus, searching for an efficient method to achieve C-doped BN nanostructure is of vital importance. Here, using density functional theory (DFT) calculations, we propose a mechanism to obtain C-doping of BN nanosheet by the interactions of two CO molecules with three kinds of defective BN nanosheets, including B or N vacancy and BN divacancy. The results show that the proposed mechanism in the present work has the following advantages: (i) the activation energies are only 0.30 and 0.37 eV for BN sheet with B and N vacancy, respectively, suggesting that this reaction can easily occur. For BN sheet divacancy configuration, because the released energy of CO-coadsorption (−5.49 eV) can completely offset the subsequent barrier (1.72 eV), C-doped BN nanosheet can also be achieved using BN nanosheet with divacancy as a reactant. (ii) No catalyst is needed, thus no extra step is needed to remove the catalyst. (3) The harmful CO molecule can be used as a reactant and transformed into CO₂ or O₂ molecule. (4) The selectivity of CO for vacancy defect sites is high. The present results provide an effective theoretical method to synthesize C-doped BN nanosheets, which would be useful for the development of BN nanosheet-based devices.