Document Type: Original Article

Author

• Mohammad Reza Jalali Sarvestani

Young Researchers and Elite Club, Yadegar-e-Imam Khomeini (RAH) Shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran

Abstract

In this research, the influence of doping graphene with silicon on the adsorption of Cd²⁺ was investigated using the infrared (IR), natural bond orbital (NBO) and frontier molecular orbital (FMO) computations. The thermodynamic parameters including Gibbs free energy changes (ΔG_ad), enthalpy variations (ΔH_ad) and thermodynamic constant (K_th) revealed that, the Si impurity made the cadmium adsorption more spontaneous, exothermic, irreversible, and experimentally feasible. The effect of temperature and geometrical situation of silicon impurities at three ortho, meta and para conditions were also evaluated. The results indicated that, the adsorption efficiency was higher at room temperature and doping graphene with silicon at the ortho position. The NBO results demonstrated that, the cadmium interaction with both pristine and Si-doped graphenes was chemisorption, which was due to formation of the covalent bonds with SP³ hybridization in all of the evaluated configurations. The applicability of the pristine and Si-doped graphenes as an electrochemical sensing material for detection of the cadmium was also assessed by the FMO parameters including, bandgap, electrophilicity, and maximum transferred charge capacity. The ortho silicon doped graphene was found to be the best recognition element for the Cd(II) as the bandgap experienced the sharpest increase from 1.82 eV to 7.74 eV in the case of this adsorbent.

Graphical Abstract

Keywords

• Cd (II)
• Graphene
• Adsorption
• Silicon
• Detection

Main Subjects

• Inorganic chemistry