In this paper, ab initio simulation of structural, electronic and methane (CH₄) adsorption properties of palladium (Pd)-decorated reduced graphene oxide (rGO) has been performed using dispersion-corrected density functional theory. The stable adsorption geometry, adsorption energy, charge transfer, charge density difference, band structure, electronic density of states and work function are calculated to give further insight into the adsorption process. The stable rGO surface is composed of some local structural motifs from combinations of oxygen-containing functional groups (hydroxyl and epoxide groups). Our calculations indicate that, owing to the hybridization of palladium d-orbitals and oxygen p-orbitals, the Pd atom binds strongly to the epoxide group with the adsorption energies of −1.47 eV and −2.70 eV for the same side (GOOH(I)) and opposite sides (GOOH(II)) coadsorption of functional groups, respectively. Our results show that CH₄ molecules act as electron dopants for rGO and thus slightly change its conductivity. We also observe that, upon the introduction of Pd atoms, the CH₄ adsorption energies of GOOH(I) and GOOH(II) significantly modifies from −0.1 eV to −0.45 eV and −0.06 eV to −0.33 eV, respectively. Moreover, the charge transfer can be magnified from −0.01 e (−0.01 e) to −0.02 e (-0.03 e) by introducing Pd atoms into GOOH(I) (GOOH(II)) in the presence of CH₄. Additionally, CH₄ adsorption changes the carrier mobility of Pd-decorated rGO. In light of these results, the Pd-decorated rGO can be a prominent candidate for CH₄ gas sensor application.

在本文中，使用色散校正密度泛函理论对钯 (Pd) 修饰的还原氧化石墨烯( rGO)的结构、电子和甲烷 (CH ₄ ) 吸附特性进行了从头模拟. 计算稳定的吸附几何、吸附能、电荷转移、电荷密度差、能带结构、电子态密度和功函数，以进一步了解吸附过程。稳定的 rGO 表面由一些局部结构基序组成，这些基序来自含氧官能团（羟基和环氧基团）的组合。我们的计算表明，由于钯 d 轨道和氧 p 轨道的杂化，Pd 原子与环氧基团以 -1.47 eV 和 -2.70 eV 的同一侧（GOOH(I) ) 和相反侧 (GOOH(II)) 官能团的共吸附。我们的结果表明 CH ₄分子充当电子掺杂剂rGO，因此略微改变其电导率。我们还观察到，在引入 Pd 原子后， GOOH(I) 和 GOOH(II)的 CH ₄吸附能分别从 -0.1 eV 显着改变到 -0.45 eV 和 -0.06 eV 到 -0.33 eV。此外，通过在 CH ₄存在下将 Pd 原子引入 GOOH(I) (GOOH(II))，电荷转移可以从 -0.01 e (-0.01 e) 放大到 -0.02 e (-0.03 e)。此外，CH ₄吸附改变了 Pd 修饰的 rGO 的载流子迁移率。根据这些结果，Pd 装饰的 rGO 可以成为 CH ₄气体传感器应用的重要候选者。