Tai Hongbo, Zhang Xuan, Rong Yang, Liu Zhiliang
Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, College of Chemistry and Chemical Engineering, Inner Mongolia University Hohhot 010021 PR China
Chem Sci. 2025 Jul 28. doi: 10.1039/d5sc02794b.
3D conductive metal-organic frameworks (c-MOFs) have emerged as a promising candidate for advancing energy storage due to excellent inherent electrical conductivity, efficient ion diffusion through open channels and high-density active sites. However, the facile preparation of 3D c-MOFs remains a great challenge. In this study, we developed two new 3D nitrogen-rich Ni-based c-MOFs (Ni-BPE and Ni-BPA) the reaction of Ni ions, 2-(3,5-dicarboxyphenyl)-6-carboxybenzimidazole (HL) and 1,2-di(4-pyridyl) ethylene dipyridyl (BPE) or 1,2-di(pyridin-4-yl) ethyne (BPA). The nitrogen-rich ligands, featuring pyridyl and benzimidazole units, extend the π-conjugation system, contributing to the high conductivity of Ni-BPE. Furthermore, compared to flexible BPE with a carbon-carbon double bond, the rigid BPA with a carbon-carbon triple bond can endow MOFs with a stronger π-electron delocalization. Owing to the advantageous properties enabled by crystal engineering, Ni-BPA exhibited an excellent electrical conductivity ( = 5.64 × 10 S m), which is 40% higher than that of Ni-BPE, accelerating electrochemical redox kinetics. Theoretical calculations confirmed the effect of electronic structure modulation on conductivity. Correspondingly, Ni-BPA produced a high specific capacitance of 532.4 F g (266.2 C g) at 1 A g, surpassing Ni-BPE by 52.1%. Notably, the Ni-BPA//AC device maintained excellent cycle stability with a capacitance retention of 91.9% and a high coulombic efficiency of 98.6% after 10 000 cycles.
三维导电金属有机框架材料（c-MOFs）因其优异的固有导电性、通过开放通道的高效离子扩散以及高密度活性位点，已成为推进能量存储的有前途的候选材料。然而，三维c-MOFs的简便制备仍然是一个巨大的挑战。在本研究中，我们通过镍离子、2-(3,5-二羧基苯基)-6-羧基苯并咪唑（HL）与1,2-二(4-吡啶基)乙烯二吡啶（BPE）或1,2-二(吡啶-4-基)乙炔（BPA）的反应，开发了两种新型的三维富氮镍基c-MOFs（Ni-BPE和Ni-BPA）。具有吡啶基和苯并咪唑单元的富氮配体扩展了π共轭体系，有助于Ni-BPE的高导电性。此外，与具有碳-碳双键的柔性BPE相比，具有碳-碳三键的刚性BPA可使MOFs具有更强的π电子离域。由于晶体工程赋予的有利性质，Ni-BPA表现出优异的导电性（σ = 5.64 × 10⁻³ S m⁻¹），比Ni-BPE高40%，加速了电化学氧化还原动力学。理论计算证实了电子结构调制对导电性的影响。相应地，Ni-BPA在1 A g⁻¹时产生了532.4 F g⁻¹（266.2 C g⁻¹）的高比电容，比Ni-BPE高出52.1%。值得注意的是，Ni-BPA//AC器件在10000次循环后保持了优异的循环稳定性，电容保持率为91.9%，库仑效率高达98.6%。
