Abstract We systematically study the geometric stability and hydrogen storage capacity of Ni atom decorated GaN monolayer (GaN-ML) with three types defects (VN, VGa and SW defect) using the first-principles calculations based on density functional theory (DFT-D2 method). For Ni-decorated defective GaN-ML, Ni atom can be stably combined on substrates due to higher binding energy, and the Ni atom can accommodate up to three H2 molecules. The H2 molecules adsorbed on Ni-decorated VGa substrate undergo a weak physical interaction. However, the Ni-decorated VN and SW defect substrates show sensitive to H2 molecules, which can satisfy the requirement for hydrogen storage. The molecular dynamics (MD) simulations show that the maximum of eight H2 molecules are stably adsorbed on the Ni atoms at room temperature with the hydrogen storage capacity of 5.36 wt%, and there is no structural deformation of the VN substrate plane. Therefore, these results indicate that the Ni-decorated defective GaN-ML can be potential candidates for better storage of H2 molecules. Our work can supply some guidance to explore promising novel hydrogen storage materials in energy storage field using group III-V nitrides.

中文翻译：

---

Ni修饰缺陷GaN单层氢吸附的第一性原理研究

摘要 我们使用基于密度泛函理论的第一性原理计算（DFT-D2 方法）系统地研究了具有三种缺陷（VN、VGa 和 SW 缺陷）的 Ni 原子装饰 GaN 单层（GaN-ML）的几何稳定性和储氢能力。 ）。对于Ni修饰的缺陷GaN-ML，由于结合能较高，Ni原子可以稳定地结合在衬底上，并且Ni原子最多可容纳三个H2分子。吸附在镍装饰的 VGa 衬底上的 H2 分子会发生弱物理相互作用。然而，Ni 修饰的 VN 和 SW 缺陷衬底对 H2 分子表现出敏感，可以满足储氢要求。分子动力学（MD）模拟表明，室温下最多 8 个 H2 分子稳定吸附在 Ni 原子上，储氢容量为 5。36 wt%，VN 衬底平面没有结构变形。因此，这些结果表明镍装饰的缺陷 GaN-ML 可以成为更好地储存 H2 分子的潜在候选者。我们的工作可以为使用 III-V 族氮化物在储能领域探索有前景的新型储氢材料提供一些指导。