Metal cluster-deposited graphene as an adsorptive material for m-xylene

Abstract

Tetramer clusters of platinum (Pt), palladium (Pd), gold (Au) and silver (Ag) deposited on pristine and defective graphenes were studied as potential adsorptive materials for m-xylene using density functional theory (DFT) calculations including van der Waals contributions to the Hamiltonian. Structural, energetic and electronic (i.e. d-band center, partial density of state and explicit charge) properties have been investigated for understanding the m-xylene adsorption process. The m-xylene adsorption capability of these materials has been compared. The calculation results revealed that Pt₄- and Pd₄–DG adsorb m-xylene via a chemisorption process, while Au₄- and Ag₄–DG adsorb m-xylene via physisorption. These insights are valuable for applying and developing carbon-based materials for volatile organic compound (VOC) removal applications, since physisorption-driven materials are suitable as sorbents while their chemisorption counterparts are suitable as catalysts in an oxidation reaction. Those properties in turn can be tuned by modulating metal adsorption on the carbon-based materials.