具有高比表面积和导电性的MOF衍生物碳材料合成面临着结构保持与催化石墨化之间的根本性权衡。本文，太原理工大学王文娟 讲师、Xiaoyang Deng、芬兰奥卢大学Feixiong Chen、天津大学赵乃勤 教授等在《ADVANCED SCIENCE》期刊发表名为“Vapor-Assisted Catalysis Enables Precise Construction of MOF-Derived Hierarchical Carbon Nanoarrays for High-Performance Supercapacitors”的论文，研究提出一种空间解耦的蒸汽辅助热解策略：将Co-MOF前驱体阵列与产生蒸汽的Zn-MOF辅助剂物理分离。热解过程中，远程锌蒸汽流通过抑制钴纳米粒子团聚来维持前驱体的纳米片层结构，同时催化生长出致密的碳纳米管阵列。
该工艺最终形成兼具高比表面积与石墨化特性的0D-1D-2D分级碳结构体系。作为自支撑超级电容器电极，优化材料展现出360 F g⁻¹的比电容、优异的倍率性能（50 A g⁻¹下保持率达53%）及强劲的循环稳定性。机理研究与密度泛函理论计算证实：锌蒸气在调控形态的钴催化过程中发挥关键作用，并揭示了杂原子与钴元素间的协同效应优化钾离子存储动力学。这种远程调控策略为设计用于先进储能的分级碳材料建立了可推广的平台。
图1、(a) Schematic illustration of the construction of HCA via a facile gas-phase-confined catalysis process. (b) XRD pattern of HCA800; (c, d) SEM images, (e) TEM image, and (f, g) HRTEM images of HCA800.
图2、(a) SEM image of the carbon material obtained through direct carbonization of A-ZIF without ZIF powder; (b) SEM image of SCA with P-ZIF(Co); (c–f) SEM images of HCA materials obtained at different temperatures; (g) TG/DSC and (h) TG-MS curves of the P-ZIF(Zn); (i) Co and (j) CH4 adsorption energy on different models; (k) Schematic diagram of the formation process for CNT arrays.
图3、(a) Nitrogen adsorption/desorption isotherm of HCA800; inset shows the pore size distribution. (b) Raman spectra of HCAs. High-resolution XPS spectra for (c) C 1s, (d) N 1s, (e) O 1s, and (f) Co 2p spectra of HCAs and SCA. (g) Total elements content and (h) contents comparison of different N and O species derived from XPS spectra.
图4、(a) CV curves of all the electrodes at 20 mV s−1; (b) CV curves of the HCA800 electrode at different scan rates; (c) GCD curves of the HCA800 electrode; (d) Specific capacitance comparison of HCAs and SCA800 electrodes; (e) Capacitive contribution of the HCA800 electrode at various scan rates; (f) Comparison of capacitive contribution; (g) GCD profiles, (h) Ragone plot, and (i) cycling performance curves of the the HCA800-based symmetrical supercapacitor.
图5、(a) Nyquist plots of the HCAs and SCA800 electrodes; (b) Linear fit for the relationship between Z′ and ω−1/2. (c) Activation energy for the AC, ZC, SCA800 and HCA800 electrodes according to the temperature-dependent EIS; (d–f) Contour maps of DRT results obtained from the in situ EIS during the charging/discharging process; (g) GCD curve and in situ Raman spectra of the HCA800 electrode; (h) Corresponding ratios of ID/IG; (i–l) Adsorption energy of K ion on different carbon models.+
图6、SEM images of (a, d) CoCu-HCA, (b, e) CoNi-HCA, and (c, f) CoZn-HCA. (g) Capacity-retention ratio of the flexible supercapacitor under various mechanical deformations. (h) CV curves of tailored flexible supercapacitor units. (i) GCD curves for single and two units connected in series and in parallel at 1.0 A g−1; inset: illustration of the device powering an LED.
综上所述，作者建立了一种蒸汽辅助催化策略，利用原位生成的锌蒸汽在热解过程中动态调控催化剂行为。该方法通过防止钴纳米颗粒聚集，并在模板化碳纳米管生长过程中保持前驱体的复杂微片层形态，实现了高度均匀的分级碳阵列（HCA）合成。所得材料兼具分级多孔性、高石墨化程度及优化杂原子掺杂特性，作为超级电容器电极时展现出卓越的倍率性能与长期循环稳定性。基于密度泛函理论计算的机理研究揭示了两大协同效应：首先，锌蒸气动态调控钴催化剂活性，同时控制碳骨架石墨化与碳纳米管均匀生长；其次，形成的Co/N/O活性位点构建出精密调谐的能量景观，既促进钾离子强吸附，又加速电荷转移与离子释放。这种优化的动力学平衡是材料高性能的基础。该设计理念的普适性通过成功应用于多种双金属MOF和PBA前驱体得到验证，确立其作为构建复杂碳结构的通用平台。该方法为制备结构与表面化学可精确调控的材料提供了强有力途径，在先进储能、催化及相关领域展现出巨大潜力。
文献：https://doi.org/10.1002/advs.202524363
