Computational study of physisorption and chemisorption of polypyrrole on H-terminated (111) and (100) nanodiamond facets

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2016-10, Vol.213 (10), p.2672-2679
• Main Authors: Matunová, Petra, Jirásek, Vít, Rezek, Bohuslav
• Format: Article
• Language: English
• Subjects: Charge transfer; Chemisorption; Contact; density functional theory; diamond; Diamonds; Mathematical analysis; nanomaterials; nanoparticles; Nanostructure; polypyrrole; Polypyrroles; Surface chemistry
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201600228

Interaction of diamond with molecules is important for various applications. For instance, experimentally observed charge transfer between bulk diamond and polypyrrole (PPy) is promising for photovoltaics. Here we explore the interactions of PPy with surfaces of nanodiamonds (NDs) by density functional theory (DFT) calculations at the B3LYP/6‐31G(d) level of theory. The most probable H‐terminated 1 × 1 (111) and 2 × 1 (100) diamond surface facets are considered. Geometrical arrangement, binding energy (Eb), interaction energy (Eint), charge transfer (Δq), and HOMO‐LUMO gap are calculated on geometrically relaxed structures of PPy on the ND facets in physisorbed or chemisorbed configuration. Energetically, the most favorable is physisorption of PPy on NDs. For chemisorption, one‐bond contact is more favorable than two‐bond contact, with the most probable binding on (100) facet. Charge transfer of electrons (up to Δq = −0.11 e−) from PPy to diamond is observed for all the configurations in the dark. In some cases, the calculations reveal spatial separation of the HOMO and LUMO, which may be useful for photovoltaic applications. Truncated octahedral ND (left), (111) facets are in blue, (100) facets are in red. (111)–(100)–(111) corner of ND (bottom), and (111) facet with chemisorbed PPy (top). C atoms are in gray, H atoms are in white, N atoms are in blue.