New Insights into H2S Adsorption on Graphene and Graphene-Like Structures: A Comparative DFT Study

Abstract

The efficient removal of pollutants from different environments has been one of the great challenges for scientists in recent years. However, the understanding of the mechanisms underlying this phenomenon is still the subject of passionate debates, mainly due to the lack of experimental tools capable of detecting events at the atomic scale. Herein, a comparative theoretical study was carried out to capture the adsorption of H2S on metal oxide surfaces such as zinc oxide (ZnO) and beryllium oxide (BeO), as well as graphene and Ni-decorated graphene. A simulation based on density-functional theory (DFT) was carried out by adopting General Gradient Approximation (GGA) under the Perdew–Burke–Ernzerhof (PBE) function. The calculations quantified H2S adsorption on the considered metal oxide sheets as well as on the non-decorated graphene having a physical nature. In contrast, H2S adsorbed on Ni-decorated graphene sheet gave an adsorption energy of −1.64 eV due to the interaction of S and Ni atoms through the formation of a covalent bond, proof of chemisorption. It seems that the graphene sheet decorated with Ni atoms is a more suitable adsorbent for H2S molecules than BeO, ZnO, or non-decorated graphene, providing a theoretical basis for future studies.

Prospect of DFT Utilization in Polymer-Graphene Composites for Electromagnetic Interference Shielding Application: A Review

“…Finally, they validated the mechanical findings obtained through the investigation of the morphology of the prepared experimental specimens by means of transmission electron microscopy (TEM) as well as scanning electron microscopy (SEM) micrographs [35]. The prediction of functional, mechanical as well as the structural character of graphene-polymer composites has been a point of attraction of study for several researchers globally within the last decade [31][32][33][34][35][36].…”

“…Graphene and its materials rGO, or GO (graphene oxide (GO) as well as reduced graphene oxide (rGO)) are 2D (two-dimensional) slabs/sheets of sp 2 and/or sp 3 carbons organized in six-grouped rings that could be chemically altered to encompass an assortment of spontaneously active functional spots [31][32][33][34][35][36]. The utmost utilized forms of graphene materials are the single, bi-layer/multi-layer graphene, including rGO, or GO.…”

“…The DFT concept in graphene/graphene-based (polymer)composite materials (GPM or GPCM) has been effectively utilized by several researchers globally [42][43][44][45][46][47][48][49][50][51][52]. In one of the instances, Salmankhani et al [32] presented a classical simulation algorithm for graphene-based materials in their report. At first, H 2 S molecules' structural adsorption upon BeO, ZnO, graphene, as well as Ni-ornamented-graphene were simulated along with geometrical optimization using DFT computations by means of SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) computer coding [31].…”

“…For the purpose of studying the electronic performance as well as associated effects, the authors embraced the GGA. They pointed out that conventional DFT methods are unsuccessful in exactly addressing the van der Waals (vdW) forces without revealing dispersion interactions, in spite of their decisive character in feebly interfacing systems [31,32]. Hence, the basic DFT for GGA calculation was thus supplemented with the ab initio vdW tactics obtainable with Grimme, denoted as the vdW-DFT technique.…”

Effect of Oxygen Plasma Treatment on the Structure and Mechanical Properties of Bilayer Graphene Studied by Molecular Dynamics Simulation

“…The pristine graphene without defects performs good mechanical properties (ultra-high elastic modulus and strength , ). Experiments on defect-free graphene based on atomic force microscopy (AFM) performed an elastic modulus of about 1 TPa and tensile strength of about 100 GPa. , However, the interaction between defect-free graphene and other molecules is not so strong, , which limits the application development in high sensitivity detection or sensors. − The sensitivity of graphene to molecules is generally enhanced by means of surface functionalization, leading to defects. , Indeed, due to the production processes, , working environment, , or the required functionality of devices, − there is almost no defect-free graphene in practical applications. The defects in the graphene lattice are inevitable and essential, so we should pay attention to the defect engineering of graphene. − …”