Department of Physics, Bharathiar University, Coimbatore, 641046, Tamil Nadu, India.
Laboratoire de Physique des Lasers, Atomes et Molécules, University de Lille, France.
Environ Res. 2022 Mar;204(Pt B):112114. doi: 10.1016/j.envres.2021.112114. Epub 2021 Sep 24.
To meet the increasing need of energy resources, hydrogen (H) is being considered as a promising candidate for energy carrier that has motivated research into appropriate storage materials among scientists. Thus, in this study for the first time, zig-zag and armchair edged tetracene based porous carbon sheet (CH) is investigated for H storage using the density functional theory. To explore the hydrogen storage capacity, the hydrogen molecule is initially positioned parallel to the CH sheet at three different sites, resulting in lower adsorption energies of -0.020, -0.024, and -0.015 eV respectively. The Li, Na, and K atoms are decorated to improve H adsorption on the CH sheet. The Li atom decorated CH sheet has a higher binding energy value of -2.070 eV than the Na and K atom decorated CH sheet. The presence of Li, Na, and K atoms on the CH sheet enhance the H adsorption energy than the H on the pristine CH sheet. The decrease of Mulliken charge in alkali metal atoms (Li, Na, and K atom) on the CH sheet reveal that the electron is transferred from H-σ orbital to s orbital of alkali metal atoms on the CH sheet, leads to the enhancement of H binding. Compared to H adsorption on Na and K atom decorated CH sheet, the H adsorption on Li atom decorated CH sheet has the maximum adsorption energy value of -0.389 eV. The obtained hydrogen storage capacity of Li, Na, and K atoms decorated CH sheets are about 7.49 wt%, 7.31 wt%, and 7.14 wt% respectively for four H molecules, which is greater than the targeted hydrogen storage capacity of the United States Department of Energy (DOE). Thus the obtained results in this work reveal that the decorated CH sheets with Li, Na, and K atom plays the potential role in the H storage.
为了满足对能源资源不断增长的需求，氢气 (H) 作为一种有前途的能源载体正受到科学家的关注，这激发了对合适的存储材料的研究。因此，在这项研究中，首次使用密度泛函理论研究了锯齿形和扶手椅边缘四并苯多孔碳片（CH）作为储氢材料。为了探索储氢能力，最初将氢分子平行放置在 CH 片的三个不同位置上，导致吸附能分别为-0.020、-0.024 和-0.015 eV。然后在 CH 片上用 Li、Na 和 K 原子进行修饰以提高对 H 的吸附。Li 原子修饰的 CH 片的结合能值为-2.070 eV，高于 Na 和 K 原子修饰的 CH 片。Li、Na 和 K 原子的存在增强了 CH 片对 H 的吸附能，比原始 CH 片上的 H 吸附能更高。CH 片上碱金属原子（Li、Na 和 K 原子）的 Mulliken 电荷减小表明电子从 H-σ 轨道转移到 CH 片上的碱金属原子的 s 轨道，从而增强了 H 的结合。与 Na 和 K 原子修饰的 CH 片上的 H 吸附相比，Li 原子修饰的 CH 片上的 H 吸附具有最大的吸附能值为-0.389 eV。Li、Na 和 K 原子修饰的 CH 片对 4 个 H 分子的储氢容量分别约为 7.49 wt%、7.31 wt%和 7.14 wt%，大于美国能源部（DOE）的目标储氢容量。因此，这项工作的结果表明，Li、Na 和 K 原子修饰的 CH 片在储氢方面具有潜在的作用。
