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基于密度泛函理论(DFT),构建二元含铝水滑石[M3Al-LDHs-NO3(M=Fe,Co,Cu,Zn)]周期性计算模型,选取CASTEP程序模块对模型进行几何优化及性质分析,通过对各体系的晶胞参数、氢键、结合能、电子性质、态密度的分析,研究了不同二价过渡金属离子对类水滑石体系稳定性的影响。结果表明:对于M3Al-LDHs-NO3体系,随着M离子原子序数的增加,各体系结合能的绝对值逐渐降低,禁带宽度逐渐变窄,主客体间静电作用力逐渐减小,氢键强度逐渐减弱,静电作用力与氢键的协同作用导致各体系的稳定性逐渐下降;此外,对于用d区元素或ds区元素作为二价金属离子所构成的二元含铝水滑石体系,前者所合成的水滑石更稳定。
Based on the density functional theory (DFT), the periodic calculation model of binary Al-LDHs-NO3 (M = Fe, Co, Cu, Zn) was established and the CASTEP program module was used to optimize the geometry and properties of the model The effects of different divalent transition metal ions on the stability of hydrotalcite-like systems were studied by analyzing the unit cell parameters such as hydrogen bonding, bonding energy, electronic properties and density of states. The results show that the absolute value of binding energy of each system decreases with the increase of atomic number of M ions, the band gap becomes narrower, the electrostatic force between host and guest decreases gradually, and the hydrogen bonding strength Gradually weakened, and the synergistic effect of electrostatic force and hydrogen bond leads to the gradual decline of the stability of the system. In addition, for the binary aluminum-containing hydrotalcite system composed of d element or ds element as divalent metal ions, Synthetic hydrotalcite more stable.