Tuning hydrogen adsorption on graphene by gate voltage

TL;DR

This paper demonstrates that applying a gate voltage can effectively control hydrogen adsorption on graphene at room temperature, combining experimental and theoretical approaches to understand the underlying mechanisms.

Contribution

The study introduces a method to tune hydrogen adsorption on graphene via gate voltage, supported by electrical measurements, microscopy, and density functional theory calculations.

Findings

Negative gate voltage increases hydrogen adsorption on graphene.

Gate voltage influences hydrogen adsorption energy and diffusion barriers.

Theoretical models explain charge doping effects on hydrogen binding.

Abstract

In order to realize applications of hydrogen-adsorbed graphene, a main issue is how to control hydrogen adsorption/desorption at room temperature. In this study, we demonstrate the possibility to tune hydrogen adsorption on graphene by applying a gate voltage. The influence of the gate voltage on graphene and its hydrogen adsorption properties was investigated by electrical transport measurements, scanning tunneling microscopy, and density functional theory calculations. We show that more hydrogen adsorbs on graphene with negative gate voltage (p-type doping), compared to that without gate voltage or positive gate voltage (n-type doping). Theoretical calculations explain the gate voltage dependence of hydrogen adsorption as modifications of the adsorption energy and diffusion barrier of hydrogen on graphene by charge doping.