Graphene sensors have high sensitivity and selectivity and are commonly used to detect and clean oil breakdown resulting gas contaminants. Silver impurities on Graphene sheet vacancy were simulated for Methane interaction with vacant Graphene layers, with and without silver impurities, based on density functional theory with Quantum ESPRESSO. PBE exchange–correlation function with GGA function and vdW-DF corrections were used. Analyzing adsorption energies revealed the effects of the additives on Graphene, and showed Graphene with silver impurities was a good option. Analyzes of methane (CH4/MVG, CH4/BVG, CH4/MVG_Ag, and CH4/ BVG_Ag) show that adsorption strengths of the structures were the relationship MVG_Ag > BVG > MVG > BVG_Ag. Adding Ag impurity to the foil greatly increases the CH4 adsorption strength of MVG_Ag and decreases the adsorption strength of BVG_Ag. Due to CH4′s symmetry, orientation relative to Graphene makes no difference as it interacts with carbon atoms from any side.
