Comparative DFT Investigation of Carbon Dioxide Adsorption, Reduction, and Sensing on Fe, Cu, and Zn-Doped Graphene with Single and Double Vacancy Defects

With the advent of industrialization and the transition toward carbon-based societies, the excessive emission of carbon dioxide has emerged as a serious environmental challenge. The increasing concentration of this gas not only intensifies the greenhouse effect but also accelerates global warming. Therefore, the reduction and conversion of CO۲ into value-added products have become critically important. Given the inherent stability of CO۲ molecules and the difficulty of their reduction, designing catalysts with novel structures capable of modifying the LUMO energy level during CO۲ adsorption is essential. In this study, the adsorption of CO۲ on graphene with single- and double-vacancy defects doped with transition metals (Fe, Cu, and Zn) was investigated. The structural optimizations were performed using density functional theory (DFT) at the B۳LYP level with the ۶-۳۱g(d) basis set, employing Gaussian ۰۹ software. The results indicate that Fe/graphene nanostructures with single-vacancy (Fe/G۱V) and double-vacancy (Fe/G۲V) defects exhibit the highest energy gap and hardness, leading to the formation of stable complexes with the ability to adsorb and reduce CO۲. Furthermore, the Zn/G۲V nanostructure, due to its significant energy gap variations, shows great potential for the development of CO۲ detection sensors.

کلیدواژه ها:

Single- and Double-Vacancy Graphene ، Metal Doping ، Carbon Dioxide ، Sensor ، Density Functional Theory ، Atoms in Molecule Theory