Synergistic coupling of heterointerface Ni2P/Co2P nanocrystals anchored on MXene nanosheets for high-performance oxygen and hydrogen evolution reactions
Abstract
The kinetic energy barrier (Ea), which significantly decreases in the intermediate transition state of adsorption, can be modulated by designed heterointerface catalysts. The intrinsic activity can be tuned to a typical multicomponent nature. Moreover, the sheet-like structures and honeycomb voids provide abundant active sites, an advantage for ion penetration and gas production. However, a significant concern is that water splitting into hydrogen and oxygen remains challenging due to a lack of stability, poor performance, and scarcity of metals. Herein, we report that a delaminated Ti3C2 MXene acts as a substrate, synergistically interacting with a bimetallic Ni2P/Co2P heterostructure. As expected, the prepared Ni2P/Co2P_8@Ti3C2 nanoporous material exhibits good performance toward OER and HER activity. It requires only 255 and 82 mV to reach 10 mA cm−2 current density with a slight Tafel slope of 61 and 89 mV dec−1 for the OER and HER, respectively, in 1.0 M KOH electrolyte. Furthermore, the Ni2P/Co2P_8@Ti3C2 electrocatalyst shows superior stability over 60 h when applied at a constant potential of 1.50 V and −1.10 V vs. a RHE. Of interest, this work demonstrated the design of a heterointerface nanoporous material with ultrathin 2D MXene nanosheets to achieve state-of-the-art activity for practical applications and next-generation energy materials.