Tailoring the Metal‐Organic Framework (MOF) Structures With Metal and Ligand Manipulating to Enhance Electrocatalytic Activity for Hydrogen Evolution Reaction

ABSTRACT Herein, we designed novel metal‐organic frameworks (MOFs) with different metal and organic linkers to investigate the influence of the type and number of the metal cations and organic linkers on their electrocatalytic performances for the hydrogen evolution reactions (HER). For this purpose, MOF structures bearing mono and dual Co, Fe, and Ni metal and benzene tricarboxylic acid (BTC) and benzimidazole (BIM) linkers were easily synthesized using a solvothermal technique. Pristine MOF modified carbon cloth (CC) electrodes were finally tested as the cathode of the water electrolyzer to enhance the HER performances. The characterizations of the MOFs indicated that the MOFs bearing Co and Fe cations were coordinated with two organic linkers and two water molecules, which facilitated their electrocatalytic activity by opening ways to the active sites of the structure. The electrocatalytic results indicated that the Co 2+ cation was found at the most active metal center, and BTC acted as the better ligand option. Among the modified electrodes, CC/Co‐BTC exhibited superior HER performances with 7.00 cm 2 of ECSA, 43 mV of overpotential, 80 mVdec −1 of Tafel slope, and excellent coulombic stability. These results indicate the possible usage of the CC/Co‐BTC electrode instead of the commercial CC/Pt electrode in practical water electrolysis processes.