College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Key Laboratory of Functional Molecular Solids , Anhui Normal University , 189 Jiuhua Southern Road , Wuhu , 241002 , People's Republic of China.
Inorg Chem. 2020 Jan 21;59(2):1295-1305. doi: 10.1021/acs.inorgchem.9b03011. Epub 2020 Jan 9.
Two-dimensional (2D) Co-based MOF-on-MOF heterojunction nanostructures with improved electrocatalytic activity were successfully constructed via a mild two-step solution route, employing Co ions as the center atoms, and 1,4-benzenedicarboxylate (BDC) and 4,4'-biphenyldicarboxylate (BPDC) as ligands. The as-obtained heterojunction nanostructures were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) technologies. Electrochemical measurements showed that as-prepared Co-BPDC/Co-BDC heterojunction nanostructures presented markedly enhanced OER electrocatalytic activity, compared with single Co-BPDC, Co-BDC, and/or their physical mixture. Also, the Co-BPDC/Co-BDC-3 heterojunction prepared after treatment for 3 h exhibited the strongest catalytic activity. To reach the current density = 10 mA cm, the Co-BPDC/Co-BDC-3 heterojunction-modified glassy carbon electrode required an overpotential of 335 mV in 1 M KOH, which was reduced by 57 and 93 mV, compared to the electrodes modified by Co-BDC and Co-BPDC, respectively. Simultaneously, the heterojunction catalyst also displayed better long-term stability. The improvement of the above performances should be attributed to the increased structure stability, BET surface area, ECSA, and electron transfer ability of the heterojunction.
通过温和的两步溶液路线，成功构建了具有改进的电催化活性的二维（2D）Co 基 MOF-on-MOF 异质结纳米结构，使用 Co 离子作为中心原子，1,4-苯二甲酸（BDC）和 4,4'-联苯二甲酸（BPDC）作为配体。所获得的异质结纳米结构通过场发射扫描电子显微镜（FESEM）、X 射线衍射（XRD）、傅里叶变换红外（FTIR）光谱、BET 表面积分析、热重分析（TGA）和 X 射线光电子能谱（XPS）技术进行了表征。电化学测量表明，与单一组分 Co-BPDC、Co-BDC 和/或它们的物理混合物相比，制备的 Co-BPDC/Co-BDC 异质结纳米结构表现出明显增强的 OER 电催化活性。此外，在处理 3 小时后制备的 Co-BPDC/Co-BDC-3 异质结表现出最强的催化活性。在 1 M KOH 中，达到电流密度 = 10 mA cm 时，Co-BPDC/Co-BDC-3 异质结修饰的玻碳电极需要 335 mV 的过电势，与 Co-BDC 和 Co-BPDC 修饰的电极相比，分别降低了 57 和 93 mV。同时，异质结催化剂还表现出更好的长期稳定性。上述性能的提高应归因于异质结结构稳定性、BET 表面积、ECSA 和电子转移能力的提高。
