Improving the HCHO Sensing Selectivity on Ag-Doped Graphene by Oxygen Functionalization: A First-Principles Study

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Graphene-based sensors often lack selectivity in detecting target gases within complex atmospheres.
• Interference from various gases compromises the accuracy of graphene sensors.

Purpose of the Study:

• To investigate the effect of oxygen functionalization on graphene's selectivity for formaldehyde (HCHO) detection.
• To compare the adsorption properties of formaldehyde and interfering gases on pristine graphene (AgG) and oxygen-functionalized graphene (AgOG).

Main Methods:

• First-principles simulations were employed to analyze gas adsorption on AgG and AgOG.
• Non-equilibrium Green's function (NEGF) method was used to evaluate the sensing properties of AgOG sensors.

Main Results:

• AgG exhibited poor selectivity for HCHO detection.
• Oxygen functionalization of graphene (AgOG) significantly improved HCHO adsorption strength and reduced adsorption of interfering gases.
• AgOG sensors showed predicted HCHO sensing responses of 76% (armchair) and 32% (zigzag).

Conclusions:

• Oxygen functionalization is a promising strategy to enhance the selectivity of graphene-based gas sensors.
• The findings provide insights for designing advanced graphene materials for precise gas detection in challenging environments.