2D/2D interfacial coupling of NiFe-LDH and Ti₃C₂T_x for oxygen evolution reaction

Designing electrocatalysts for electrochemical water splitting to generate renewable energy has been a prospective interest throughout the previous decade. The efficiency of electrochemical water splitting, however, is impeded by the sluggish kinetics of the oxygen evolution reaction (OER). Herein, the heterostructure of layered double hydroxides (NiFe-LDH) and MXene (Ti₃C₂T_x) were synthesized via hydrothermal (NiFe-LDH/Ti₃C₂T_x-H) and physical mixing (NiFe-LDH/Ti₃C₂T_x-P) methods. The NiFe-LDH/Ti₃C₂T_x-H exhibited an overpotential of 269 mV at 10 mA cm⁻², indicating superior performance as compared to NiFe-LDH/Ti₃C₂T_x-P (353 mV) and RuO₂ (313 mV). The double layer capacitance (C_dl) of NiFe-LDH/Ti₃C₂T_x-H was higher (2.05 mF cm⁻²) as compared to NiFe-LDH/Ti₃C₂T_x-P (1.63 mF cm⁻²), thus indicating more active sites for improving reaction kinetics. Additionally, the NiFe-LDH/Ti₃C₂T_x-H electrocatalyst retained stable performance (96.1%) after 10 h of chronopotentiometry at a constant current density of 10 mA cm⁻².