Having anticipated theoretically in 19941, boron nitride nanotubes (BNNTs) were synthesizedsuccessfully 1 year later2. Notwithstanding remarkable structural resemblanceto carbon nanotubes (CNTs), BNNTs have been the subject of a wide array ofgroundbreaking studies owing to their idiosyncratic properties. Unlike metallicor semiconducting CNTs, BNNTs are electrically insulating which is stemmed fromtheir roughly constant band gap of ~5.5eV and that the gap bears practically norelation to the tube chirality, morphology, diameters, and number of walls.
Inaddition, in comparison with CNTs, BNNTs demonstrate astonishing chemical andthermal stability3-6. Indisputably, possessing outstandingmechanical properties7,8, high thermal conductivity9, specific electronic behavior10, intrinsic piezoelectric feature11, and high temperature oxidation resistance12, BNNTs are one of the strong contenders fortechnological applications; i.e.
, catalysis13, electronic and optical devices14, hydrogen storage15, nanotransistors16, gas sensors17, bioapplications18, UV solid-state emitters19, and drug delivery20. Consequently, a wide variety of well-establishedmethods have been attempted to fabricate BNNTs, including arc-discharge,chemical vapor deposition (CVD), laser ablation, plasma-jet technique, and soon21. Rarely did experimental synthesisramifications demonstrate that BNNTs are perfect22. Instead, diverse types of defects such as B orN vacancies, C and transition-metal doping, pentagons, heptagons, dopants, andStone-Wales (SW) defect could have been formed in the process of preparationsor modifications of BNNTs9. Needless to say, these defects are to provecrucial to the properties of BNNTs, for example not only does SW defectdiminish slightly the band gap of BNNTs, but it also enhances their ability to adsorbor detect several gases923. Furthermore, it has been manifested that chemicalreactivity of defective structures is higher than the one in pristine BNNTs22. Although various state-of-the-arttechnological applications which have been innovated are benefiting fromdistinctive BNNTs’ properties, several obstacles like insolubility in usualsolvents or wide band gap restrict utilizing of BNNTs for further implementation16. Among feasible methods to resolveaforementioned challenges, chemical functionalization of BNNTs has beendemonstrated to be one of the most efficacious strategies24.
Applying this method, manifold theoretical andexperimental investigations have been carried out to probe the interaction ofBNNTs with different chemical species such as H2325, F26,27,