First-principles investigation of noble metal-decorated reduced Graphene Oxide for ultrasensitive detection of Methane

Methane (CH₄) detection is essential for industrial safety, environmental monitoring, and various technological applications. Reduced graphene oxide (rGO) has shown significant promise as a gas-sensing material, particularly when decorated with noble metals using palladium (Pd), platinum (Pt), or gold (Au). This research explores the potential of noble metal-decorated rGO for CH₄ detection through advanced computational methods, including density functional theory (DFT) and non-equilibrium Green’s function (NEGF) approaches. The study systematically examines the structural, electronic, adsorption, and current–voltage (I–V) characteristics of rGO systems decorated with Pd, Pt, and Au. The findings reveal that noble metal atoms strongly bind to the rGO surface, markedly improving its chemical reactivity and electronic transport properties. Among the configurations analyzed, Pd-decorated rGO (rGO-Pd) demonstrated the highest CH₄ adsorption efficiency, surpassing rGO-Pt and rGO-Au. Sensing response values were recorded as 50.15%, 84.23%, 60.45%, and 20.5% for rGO/CH₄, rGO-Pd/CH₄, rGO-Pt/CH₄, and rGO-Au/CH₄, respectively, within a bias voltage range of 0 to 2.4 V. These results highlight rGO-Pd as an optimal material for CH₄ detection, offering significant potential for creating effective and reliable gas sensors. The computational insights gained in this study contribute to the advancement of rGO-based chemiresistive sensors for practical applications.