Construction\nof ZIF-67-On-UiO-66 Catalysts as a Platform\nfor Efficient Overall Water Splitting

Abstract

A well-organized construction of hybrid metal–organic\nframeworks\n(MOFs) with exquisite structures is vital due to their potential applications.\nHerein, a novel hybrid nanostructure of UiO-66-on-ZIF-67, denoted\nas MZU-Co_<i>x</i>Zr_<i>y</i> (<i>x</i> and <i>y</i> represent the mass ratios\nof ZIF-67 and UiO-66, respectively), was successfully prepared by\na simple method and showed a highly efficient and stable bifunctionality\nof both oxygen evolution reaction (OER) and hydrogen evolution reaction\n(HER) in an alkaline medium. The MZU-Co_2.5Zr₁ shows remarkable OER performance with a low overpotential of 252\nmV and an overpotential of 172 mV @ 10 mA/cm² for HER in\n1 mol/L KOH. With MZU-Co_2.5Zr₁ as the cathode\nand anode, the integrated water decomposition device has achieved\nlow total potentials of 1.56 V @ 10 mA/cm² and 1.59 V @\n30 mA/cm², exhibiting its excellent performance of overall\nwater splitting. Based on the experimental results, the mechanism\nof the superior electrocatalytic performance of MZU-Co_<i>x</i>Zr_<i>y</i> was discussed. This\nwork supplies guidance for the rational design of non-precious composites\nfor energy conversion.