Interfacial Strain-Modulated Nanospherical Ni 2 P by Heteronuclei-Mediated Growth on Ti 3 C 2 T x MXene for Efficient Hydrogen Evolution.

Interface modulation of nickel phosphide (Ni 2 P) to produce an optimal catalytic activation barrier has been considered a promising approach to enhance the hydrogen production activity via water splitting. Herein, heteronuclei-mediated in situ growth of hollow Ni 2 P nanospheres on a surface defect-engineered titanium carbide (Ti 3 C 2 T x ) MXene showing high electrochemical activity for the hydrogen evolution reaction (HER) is demonstrated. The heteronucleation drives intrinsic strain in hexagonal Ni 2 P with an observable distortion at the Ni 2 P@Ti 3 C 2 T x MXene heterointerface, which leads to charge redistribution and improved charge transfer at the interface between the two components. The strain at the Ni 2 P@Ti 3 C 2 T x MXene heterointerface significantly boosts the electrochemical catalytic activities and stability toward HER in an acidic medium via a combination between experimental results and theoretical calculations. In a 0.5 m H 2 SO 4 electrolyte, the Ni 2 P@Ti 3 C 2 T x MXene hybrid shows excellent HER catalytic performance, requiring an overpotential of 123.6 mV to achieve 10 mA cm -2 with a Tafel slope of 39 mV dec -1 and impressive durability over 24 h operation. This approach presents a significant potential to rationally design advanced catalysts coupled with 2D materials and transition metal-based compounds for state-of-the-art high efficiency energy conversions.