Water splitting on single Fe atom catalyst anchored on defective graphene surfaces by using first-principles density functional theory. The structure and electronic features of isolated Fe atom anchored on three graphene surfaces with single vacancy (SV), double vacancy (DV) and Stone-Wales structure (SW) defect were systematically explored. The three structures prove to be high activity and high stability on catalytic. The adsorption and the energy barrier of water splitting as well as hydrogen adsorption free energy ΔG_H∗ on single-atom Fe were also studied. The sequence of promoted splitting activity is found to be Fe@SW > Fe@DV > Fe@SV. Furthermore, by hydrogen adsorption free energy ΔG_H∗ analysis, we predict that the HER catalytic activity of graphene nanosheet can be improved by anchoring Fe atom on SV and DV structures, which are comparable to or even better than noble metals. It is found that the catalytic activity of water splitting and HER can be changed with the shift in d-band center with respect to Fermi-level. Detailed investigations on electronic structure of Fe@graphene catalytic systems disclose an obvious orbital hybridization coupling and charge transfer between atom Fe on carbon surfaces and water molecule. These results provide us with new insight into design of high performer and low-cost catalysts and may inspire potential applications in the fields of clean and renewable energy.

使用第一性原理密度泛函理论在锚定在缺陷石墨烯表面上的单铁原子催化剂上进行水分解。系统研究了锚定在具有单空位（SV）、双空位（DV）和斯通威尔士结构（SW）缺陷的三个石墨烯表面上的孤立铁原子的结构和电子特征。这三种结构被证明对催化具有高活性和高稳定性。还研究了单原子Fe上的水分解吸附和能垒以及氢吸附自由能ΔGH * _。发现促进分裂活动的顺序是 Fe@SW > Fe@DV > Fe@SV。此外，由氢吸附自由能 Δ G _H∗通过分析，我们预测石墨烯纳米片的 HER 催化活性可以通过将 Fe 原子锚定在 SV 和 DV 结构上来提高，这与贵金属相当甚至更好。发现水分解和HER的催化活性可以随着d带中心相对于费米能级的移动而改变。对 Fe@graphene 催化体系电子结构的详细研究揭示了碳表面上的 Fe 原子与水分子之间明显的轨道杂化耦合和电荷转移。这些结果为我们提供了对高性能和低成本催化剂设计的新见解，并可能激发在清洁和可再生能源领域的潜在应用。