Prussian blue analogue-derived CoP nanocubes supported on MXene toward an efficient bifunctional electrode with...

The exploration of bifunctional catalyst with economic, durable, and efficient performance plays a crucial role to boost both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in overall water splitting. Herein, we report a feasible strategy to design effective heterostructure between CoP and Ti₃C₂T_x MXene (denoted as CoP/Ti₃C₂T_x). This approach allows for the growth of CoP nanoparticles with uniform size of 5 nm on the Ti₃C₂T_x MXene, further enhancing the water electrolysis efficiency. The CoP/Ti₃C₂T_x bifunctional catalyst demonstrates an exceptional HER activity with a satisfactory overpotential of 103 mV at 10 mA cm^-2, and also can drive 10 mA cm^-2 for OER with the overpotential of 312 mV in 1.0 M KOH. Moreover, the CoP/Ti₃C₂T_x-based electrolyzer exhibits high electrochemical stability for 24 h with a low required voltage of 1.66 V at 10 mA cm^-2. The density functional theory (DFT) calculations reveal that the introduction of Ti₃C₂T_x MXene significantly adjusts d-band center towards Fermi level and expand total density of states, resulting in great electrical conductivity, enhanced water adsorption, and activation. This study provides an available mode for effective design and construction of non-noble-metal-based dual-functional catalyst toward practical energy conversion.