First-principle calculations on the structures and electronic properties of the CO-adsorbed (SnO 2 ) 2 clusters
- PDF / 786,154 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 103 Downloads / 195 Views
ORIGINAL RESEARCH
First-principle calculations on the structures and electronic properties of the CO-adsorbed (SnO2)2 clusters Zhen Zhao 1
&
Zhi Li 2
Received: 14 April 2020 / Accepted: 30 April 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract To clear the adsorption site of CO on the surface of the nanosized SnO2 film, the structures, stability, and electronic characteristics of the CO-adsorbed (SnO2)2 clusters have been investigated by using PW91 functional. The more stable configurations of these CO(SnO2)2 clusters derive from CO are adsorbed on the lower energy excited-state (SnO2)2 clusters rather than on the groundstate (SnO2)2 clusters. The calculated adsorption energies for CO on the lower energy excite-state (SnO2)2 clusters are up to 1.363–1.454 eV which is transferred from physical adsorption to chemical adsorptions. CO adsorption increases the kinetic stability and decreases the conductivity of the lower energy excited-states (SnO2)2 clusters. Keywords SnO2 clusters . First-principles . Structures . CO adsorptions
Introduction Semiconductor metal oxides have been considered as effective gas-sensing elements for many years because their electrical conductivity changes greatly with the surrounding gas atmosphere [1]. SnO2 is applied widespread as a sensor to reduce gas and hydrocarbon catalysis and as a transparent conductor [2]. It is derived from the unique electrical properties such as high carrier concentration and low resistivity [3]. It has an advantage of high sensitivity to many reducing gases [4]. SnO2 as CO sensors has been paid special attention as CO poses significant health risks [1, 5–9]. It can even detect low concentrations of CO, which is much lower than the immediate harms to life [10]. Gas-sensing with nanosized SnO2 film has outstanding capability to detect various toxic gases at lower concentrations [4]. Due to the composition and morphology of the surface obviously affecting the sensing and catalytic properties of SnO2 [11, 12], advance nanotechnology and man ufa ctur ing m e thod s ar e he lpfu l to c onstr uct
* Zhen Zhao [email protected] 1
School of Chemistry and Life Science, Anshan Normal University, Anshan 114007, People’s Republic of China
2
School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, People’s Republic of China
nanostructured SnO2 with controlled morphology, electrical properties, and surface-to-volume ratio [1]. The films involved SnOx clusters has been obtained by plasma techniques [13]. Porous SnO2 films have been prepared from clusters by the spin-coating means [4]. The response and performance of components are mainly determined by the size and shape of films [12]. The surface energy of SnO2 nanoparticles depends on the size of particles and decreases with decreasing particle size [14]. The charge transfer with adsorbates will change in electrical conductivity of these nanostructured materials [8]. However, the change in electrical conductivity of the nanostructured m
Data Loading...
