Author:

Keywords:

Science & Technology, Physical Sciences, Technology, Chemistry, Multidisciplinary, Materials Science, Multidisciplinary, Chemistry, Materials Science, density functional theory, few-atom gold cluster, field-effect transistor, graphene, oxygen adsorption and activation, MOLECULAR-OXYGEN, GAS, DISSOCIATION, RESONATORS, ACTIVATION, MONOLAYER, CATALYSIS, OXIDATION, NOBLE, O-2, C14/17/080#54271200, 0306 Physical Chemistry (incl. Structural), 0912 Materials Engineering, 3403 Macromolecular and materials chemistry, 4016 Materials engineering, 5104 Condensed matter physics

Abstract:

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Graphene's sensitivity to adsorbed particles has attracted widespread attention because of its potential sensor applications. Size-selected few-atom clusters are promising candidates as adparticles to graphene. Due to their small size, physicochemical properties are dominated by quantum size effects. In particular, few-atom gold clusters demonstrate a significant catalytic activity in various oxidation reactions. In this joint experimental and computational work, size-selected gold clusters with 3 and 6 atoms adsorbed on graphene field-effect transistors and their interaction with molecular oxygen are investigated. While oxygen adsorbs at both cluster sizes, there is a pronounced cluster size dependence in the corresponding doping, as demonstrated via first-principle calculations and electronic transport measurements. Furthermore, the doping of gold cluster decorated graphene changes sign from n- to p-doping upon oxygen adsorption, directly evidencing electron transfer to the oxygen molecules and hence their activation. These observations pinpoint graphene as a valuable platform to investigate and exploit size-dependent cluster properties.