First principles calculation on the structure and electronic properties of BNNTs functionalized with isoniazid drug molecule

Nabanita Saikia,Swapan K Pati,Ramesh C Deka

doi:10.1007/s13204-012-0124-6

Nabanita Saikia, Swapan K Pati + Show 1 more

Open Access

https://doi.org/10.1007/s13204-012-0124-6

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Abstract

One-dimensional nanostructures such as nanowires and nanotubes are stimulating tremendous research interest due to their structural, electronic and magnetic properties. We perform first principles calculation using density functional theory on the structural, and electronics properties of BNNTs adsorbed with isoniazid (INH) drug via noncovalent functionalization using the GGA/PBE functional and DZP basis set implemented in SIESTA program. The band structure, density of states and projected density of states (PDOS) plots suggest that isoniazid prefers to get adsorbed at the hollow site in case of (5,5) BNNT, whereas in (10,0) BNNT it favours the bridge site. The adsorption energy of INH onto (5,5) BNNT is smaller than in (10,0) BNNT which proposes that (10,0) BNNT with a larger radius compared to (5,5) BNNT is more favourable for INH adsorption as the corresponding distortion energy will also be quite lower. Functionalization of (5,5) and (10,0) BNNTs with isoniazid displays the presence of new impurity states (dispersionless bands) within the HOMO–LUMO energy gap of pristine BNNT leading to an increase in reactivity of the INH/BNNT system and lowering of the energy gap of the BNNTs. The PDOS plots show the major contribution towards the dispersionless impurity states is from INH molecule itself rather than from BNNT near the Fermi energy region. To summarize, noncovalent functionalization of BNNTs with isoniazid drug modulates the electronic properties of the pristine BNNT by lowering its energy gap with respect to the Fermi level, as well as demonstrating the preferential site selectivity for adsorption of isoniazid onto the nanotube sidewalls of varying chirality.

Highlights

In complete analogy to carbon nanotubes (CNT) which are quasi-one dimensional nanomaterials exhibiting unique structural based electronic properties depending on the nanotube diameter and chirality, boron nitride nanotubes (BNNTs) are wide band gap semiconductors the electronic property of which is independent of the nanotube diameter and helicity and wall number (Rubio et al 1994; Blase et al 1994)
Upon adsorption of INH onto (5,5) BNNT, the hollow site is preferred for adsorption whereas in (10,0) BNNT, the bridge site is preferred at an adsorption energy value of -0.738 eV
The functionalization of BNNT with INH brings about noticeable influence in the electronic property of BNNT and introduces new dispersionless bands within the HOMO–LUMO gap of pristine BNNT, resulting in the lowering of the energy gap and increase in reactivity of the system

Summary

Introduction

In complete analogy to carbon nanotubes (CNT) which are quasi-one dimensional nanomaterials exhibiting unique structural based electronic properties depending on the nanotube diameter and chirality, boron nitride nanotubes (BNNTs) are wide band gap semiconductors (band gap of *3.5–5.5 eV) the electronic property of which is independent of the nanotube diameter and helicity and wall number (Rubio et al 1994; Blase et al 1994). Noncovalent functionalization of BNNTs with isoniazid drug modulates the electronic properties of the pristine BNNT by lowering its energy gap with respect to the Fermi level, as well as demonstrating the preferential site selectivity for adsorption of isoniazid onto the nanotube sidewalls of varying chirality.

Results

Conclusion