Examining O adsorption on pristine and defective popgraphene sheets: A DFT study

Area of Science:

• Materials Science
• Computational Chemistry
• Surface Science

Background:

• Popgraphene (PopG) is a 2D carbon allotrope with unique pentagonal and octagonal ring structures.
• PopG shares graphene's desirable properties like metallic band gap and excellent stability.
• Its potential as a gas adsorbent, particularly for oxygen, remains an area of active research.

Purpose of the Study:

• To theoretically investigate the electronic and structural properties of PopG monolayers for oxygen adsorption.
• To explore the effects of doping (Platinum, Silicon) and vacancies on PopG's oxygen adsorption capabilities.
• To calculate adsorption energies and recovery times for oxygen molecules on PopG.

Main Methods:

• Density Functional Theory (DFT) simulations with Van der Waals corrections (DFT-D) were employed.
• The DMol3 code within Biovia Materials Studio was used for calculations.
• Generalized Gradient Approximation (GGA) with Perdew-Burke-Ernzerhof (PBE) functional and a DZP basis set were utilized, including BSSE correction.

Main Results:

• Pristine and vacancy-endowed PopG exhibit physisorption of O2 with energies of 0.57-0.59 eV, primarily involving octagonal rings.
• Platinum and Silicon doping enhance O2 adsorption near octagonal rings, leading to chemisorption with energies of 1.13-2.56 eV.
• The interaction of O2 with pristine and vacancy-endowed PopG can alter electronic properties before O2 diffusion.

Conclusions:

• PopG demonstrates potential as an oxygen adsorbent, with doping significantly improving adsorption strength.
• The adsorption mechanism is strongly influenced by the octagonal ring structures in PopG.
• Further studies on doped PopG could lead to advanced gas sensing materials.