Saadu Itas Yahaya, Khandaker Mayeen Uddin, Mahmoud Mustafa
Applied Physics and Radiation Technologies Group, CCDCU, School of Engineering and Technology, Sunway University 47500 Bandar Sunway Selangor Malaysia
Department of Physics, Bauchi State University Gadau Nigeria
RSC Adv. 2025 Jan 29;15(5):3047-3059. doi: 10.1039/d4ra08592b.
Investigations on two-dimensional materials for efficient carbon dioxide (CO) capture and storage have recently attracted much attention, especially in the global industrial sector. In this work, the CO uptake by three configurations of two-dimensional magnesium oxide was investigated using density functional theory. CO capture analysis was performed considering the geometrical, thermophysical, vibrational, electronic and optical properties. Results indicated that CO adsorption by magnesium oxide (MgO) sheets is a spontaneous process accompanied by a decrease in Gibbs free energy. Moreover, the CO molecular entropy and enthalpy of the CO adsorbed sheet were decreased, indicating that the entire process was enthalpy-driven. Among the pristine, vacant and nickel-doped (Ni-doped) MgO sheets, the Ni-doped system was found to have the highest values of Gibbs free energy, enthalpy and entropy in the order of -51.366 kJ mol, -65.105 kJ mol and 127.606 J mol, respectively. It was also found to adsorb CO in the ultraviolet and visible (UV-Vis) regions within the range of 100-850 nm. Electronic interactions demonstrated that metallicity was significantly induced on the MgO sheet Ni impurity states, which enhanced the adsorption ability. Notably, hybrid orbitals between p and p revealed strong physisorption, as confirmed by the partial density of states (PDOS). The findings of this research promote CO capture sustainability by encouraging future experimentalists to use two-dimensional MgO as a better surface for CO capture.
二维材料用于高效二氧化碳（CO₂）捕获与存储的研究近来备受关注，尤其是在全球工业领域。在本研究中，利用密度泛函理论研究了二维氧化镁三种构型对CO₂的吸附情况。考虑到几何、热物理、振动、电子和光学性质进行了CO₂捕获分析。结果表明，氧化镁（MgO）片吸附CO₂是一个自发过程，同时吉布斯自由能降低。此外，被吸附CO₂的片层中CO₂分子的熵和焓均降低，表明整个过程是焓驱动的。在原始、空位和镍掺杂（Ni掺杂）的MgO片中，发现Ni掺杂体系的吉布斯自由能、焓和熵值最高，分别为-51.366 kJ/mol、-65.105 kJ/mol和127.606 J/mol。还发现它在100 - 850 nm范围内的紫外和可见光（UV-Vis）区域吸附CO₂。电子相互作用表明，MgO片上的Ni杂质态显著诱导了金属性，从而增强了吸附能力。值得注意的是，如态密度（PDOS）所证实的，p轨道和p轨道之间的杂化轨道显示出强烈的物理吸附。本研究结果通过鼓励未来的实验人员将二维MgO用作更好的CO₂捕获表面，促进了CO₂捕获的可持续性。
