O2 dissociation on the side wall of aluminum nitride nanotube: a DFT investigation

• The triplet and singlet dissociation pathways with temperature effect respectively for triplet and singlet O2 on AlNNT.
• Spin conversion between the singlet and triplet dissociation potential energy surfaces.
• The diameter effect on the dissociation.
• The electronic structures of AlNNT with O2 dissociation.

The probabilities of the singlet and triplet O2 dissociation on single-walled aluminum nitride nanotube (AlNNT) were explored here. The results suggest that the dissociation of singlet and triplet O2 on AlNNT go through intermediates on their pathways. Triplet O2 was found to be difficult to dissociate on (8, 0) AlNNT following the triplet dissociation pathways due to the high overall dissociation barriers that are greater than 1.48 eV. The singlet O2 can dissociate on the nanotube following the singlet dissociation pathways with a lower dissociation barrier of 0.74 eV. The effect of temperature was also considered and the results at room temperature indicated the unfavorable triplet dissociation barriers remained higher than 1.35 eV. In contrast, a higher temperature helps facilitate the singlet pathway dissociation barrier to be decreased to 0.65 eV at 298.15 K. However, the overall dissociation of the triplet O2 on (8, 0) AlNNT decreases to 0.95 eV at 0 K and 0.86 eV at 298.15 K due to the spin–orbital coupling. With the decreasing of the overall dissociation barriers with increasing diameter of the nanotube, it can be further addressed that both singlet and triplet O2 can dissociate on AlNNT but more strict condition is needed for triplet O2 dissociation such as AlNNT with large diameter or high temperature. Moreover, the electronic structure of AlNNT would be modified and its conductivity increases when interacting with O2. The results presented here will be a guide for application of AlNNT in nanodevices such as detecting O2 and spintronics applications.