Steering the construction of amorphous/crystalline hierarchical structure for accelerating the oxygen evolution reaction rate

Abstract

As electrochemical water splitting is an extremely promising direction for solving future energy problems and the oxygen evolution reaction (OER) is the key half-reaction in water splitting, it is necessary to develop a new type of highly active and stable non-noble metal catalyst. Herein, we construct a series of hierarchical structure by modifying ZIF-67 on clustered-MnO2 nanotubes which are used as precursor. The fruit@branch-shaped compounds, marked as X@MnO2 (X = CoSx, Co3O4 and CoP). Compared with pure MnO2 nanotubes, the obtained derivatives imaginably result in the unique hierarchical structure and introduce synergistic effect between MnO2 and Co-based species that result in higher performance. In Particular, owing to the abundant active sites, a facil mass transfer pathway and improved electrical conductivity in amorphous/crystallize hierarchical structure, CoSx@MnO2 possesses the highest electrocatalytic activity with a lower overpotential of 329 mV at the current density of 10 mA cm−2, which is superior to most MnO2-based catalyst previously reported. Most importantly, to expand this strategy is an effective way to synthesize more high-activity catalysts.