Adsorption of transition-metal atoms on two-dimensional hexagonal boron nitride monolayer: A First-principles study

Muahammad Rafique Naich, Muhammad Hassan, Aziza Aftab, Imran Nazir Unar, Hidayatullah Mahar, Sadiq Hussain, Kanwar Saleem Akhtar

Abstract


Adsorption of transition-metal atoms on (3×3) two-dimensional (2D) hexagonal boron-nitride (h-BN) monolayer has been investigated using plane-wave ultrasoft pseudo potential method based on density functional theory. Main focus have been placed on modified optical and electronic properties of the BN monolayer due to presence of adsorbate atoms. We have systematically investigated the adsorption of transition-metals atoms including (Ni, Fe, Co, Mn, and Cr) and it was found that these transition-metal atoms can be chemically adsorbed on 2D h-BN monolayer and that the process of adsorption is mainly exothermic. Firstly we determined the electronic and optical properties of (3×3) 2D h-BN monolayer without any adsorbate and it was observed that the band gap is around 4.744 eV. Upon adsorption of transition atoms band gap energy is reduced (< 1 eV). During adsorption Cr and Ni adsorb on Nitrogen atom of BN while Mn, Fe and Co adsorb on boron atom of BN. Cr, Ni, Fe and Co easily adsorb on h-BN and Mn forms weak bond with BN monolayer. The absorption peak of h-BN without any adsorbate is around 6.5 × 104 cm-1, and it is reduced to 5.5 × 104 cm-1 when transition atoms are adsorbed on h-BN. In most cases transition-metal atoms adsorption process can introduce impurity states in the band gap of h-BN due to presence of valence electrons in s and d orbital, thereby band gap theory was reduced.

Keywords


Adsorption, Transition-metal, Band gap, Absorption

Full Text: 289_JPIChE 44(1) 2016

Published by Pakistan Institute of Chemical Engineers (PIChE)

Head Office

F-4 Greenwood Market, Barkat Market, New Garden Town, Lahore

Email: info@piche.org.pk