Construction of ZIF-67-On-UiO-66 Catalysts as a Platform for Efficient Overall Water Splitting.

A well-organized construction of hybrid metal-organic frameworks (MOFs) with exquisite structures is vital due to their potential applications. Herein, a novel hybrid nanostructure of UiO-66-on-ZIF-67, denoted as MZU-Co x Zr y ( x and y represent the mass ratios of ZIF-67 and UiO-66, respectively), was successfully prepared by a simple method and showed a highly efficient and stable bifunctionality of both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in an alkaline medium. The MZU-Co 2.5 Zr 1 shows remarkable OER performance with a low overpotential of 252 mV and an overpotential of 172 mV @ 10 mA/cm 2 for HER in 1 mol/L KOH. With MZU-Co 2.5 Zr 1 as the cathode and anode, the integrated water decomposition device has achieved low total potentials of 1.56 V @ 10 mA/cm 2 and 1.59 V @ 30 mA/cm 2 , exhibiting its excellent performance of overall water splitting. Based on the experimental results, the mechanism of the superior electrocatalytic performance of MZU-Co x Zr y was discussed. This work supplies guidance for the rational design of non-precious composites for energy conversion.