A Facile Electrosynthesis of Terephthalate (tp)‐Based Metal‐Organic Framework, Ni3(OH)2(H2O)2(tp)2 with Superior Catalytic Activity for Hydrogen Evolution Reaction

Utilizing a facile one‐step electrodeposition method, several terephthalate (tp)‐based MOFs, M 3 (OH) 2 (H 2 O) 2 (tp) 2 (M = Ni, Co or Fe) have been synthesized on Ni foam (NF) or carbon cloth (CC). Among the MOFs, Ni‐MOF/NF shows porous nanosheet arrays on NF and exhibits extraordinary hydrogen evolution reaction (HER) catalytic activity with an overpotential (η 10 ) of 60 mV to reach a current density of –10 mA cm –2 , which is superior to Co‐MOF/NF (η 10 = 184 mV) and Fe‐MOF/NF (η 10 = 203 mV), and even comparable to Pt/C (η 10 = 23 mV), indicating the HER performance is associated with the species of metal ions and the morphology. In addition, it is primarily investigated the formation mechanism of Ni‐MOF nanosheet arrays on Ni foam. Furthermore, Ni‐MOF/NF can endure 50 h‐electrolysis test at –20 mA cm –2 in alkaline condition. Density functional theory (DFT) calculations identify the active site of Ni3(OH) 2 (H 2 O) 2 (tp) 2 for HER is the O‐site from the coordinated ‐OH group (ΔG H =–0.40 eV) rather than the O‐site from the coordinated H 2 O molecule (ΔG H = –1.75 eV).