Hydrogen adsorption on Ga-doped bilayer graphene: A DFT study--颗粒学报PARTICUOLOGY

a School of Artificial Intelligence, Chongqing University of Technology, Chongqing, 401135, China
b Salt Lake Chemical Engineering Research Complex, Qinghai University, Xining, 810016, China
c Key Laboratory of Salt Lake Chemical Material of Qinghai Province, Xining, 810016, China
d School of Chemical Engineering, Qinghai University, Xining, 810016, China
e College of Science, Chongqing University of Technology, Chongqing, 400054, China

10.1016/j.partic.2025.03.009

Volume 100, May 2025, Pages 103-115

Received 10 November 2024, Revised 9 February 2025, Accepted 11 March 2025, Available online 24 March 2025, Version of Record 1 April 2025.

E-mail: zhangqingwei@cqut.edu.cn

Highlights

• A new Ga-doped graphene was designed for a potential H2 storage performance using DFT method.

• This work compares adsorption energies of intrinsic and doped graphene systems for adsorption of single and multiple H₂.

• Introduction of d orbital doped Ga atoms improves adsorption effect of graphene substrate on H₂.

Abstract

Hydrogen, as an environmentally friendly energy source, is pivotal in its storage methods for its development and effective utilization. Graphene boasts advantages such as high specific surface area, excellent electrical properties, and high tunability, making it highly promising for hydrogen storage applications. Compared to monolayer graphene, bilayer graphene exhibits a more easily controllable bandgap, showcasing its potential for hydrogen storage. Additionally, to further enhance the hydrogen adsorption capability of graphene-based substrates, doping methods are commonly employed to adjust their electrical properties. This study proposes a model for hydrogen adsorption on bilayer graphene to investigate its hydrogen storage capacity. Specifically, density functional theory (DFT) computational methods are utilized to study the adsorption of single and multiple hydrogen molecules on monolayer and bilayer graphene, with or without doping with gallium atoms. Furthermore, the underlying reasons for the enhanced hydrogen adsorption in gallium-doped bilayer graphene are systematically analyzed and elucidated. The research findings indicate that pristine graphene exhibits relatively low sensitivity to hydrogen gas, with adsorption energies of only −0.078 and −0.096 eV for monolayer graphene (MG) and bilayer graphene (BG), respectively. However, upon doping gallium atoms into MG and BG, the adsorption energy significantly increases by approximately 30.8 % and 54.1 %. For adsorbing 8 H₂, with average adsorption energies reaching -0.102 eV and −0.163 eV, which is primarily due to the electron in the s orbital of H has been transferred to the d orbital of transition metal Ga. These results indicate that gallium-doped bilayer graphene holds great promise as a hydrogen storage material.

Graphical abstract

Keywords

Density functional theory; H₂ adsorption; Ga-doped graphene; Density of state

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