Ab initio studies of hydrogen and oxygen chemisorptions on the cubic BN(1 1 1) surface

Abstract

The chemisorption states of oxygen molecule, atomic oxygen, hydrogen and hydroxyl radicals on B-terminated c-BN(1 1 1)-1 × 1 and 2 × 1 surface structures have been examined using periodic density functional theory calculations. The c-BN(1 1 1) bulk-truncated boron-face is coordinatively unsaturated and show DOS states in the gap region, these states are removed following surface passivation by H and O atoms. The 2 × 1 reconstruction on the BN(1 1 1) face is found to be energetically more favourable by 4.08 eV compared to the 1 × 1 face. The singlet state is the ground state for all adsorbed systems here. Co-adsorption of H on the B-N Pandey chains is more favourable than lone hydrogen adsorption on either B or N. Molecular oxygen can chemisorb in a peroxy fashion on the B-N Pandey chain. For the 2 × 1 B face, the only stable structure to atomic O is a bridging oxygen position between B and N, with an adsorption energy of -3.23 eV per O atom. If the O atom is positioned above the B, the 2 × 1 B face will revert to 1 × 1 structure following dynamic optimization at 300 K, due to the strong interaction between boron atoms and these species. © 2005 Elsevier B.V. All rights reserved.