Magnetic Field-Assisted Anchoring of High-Density Pt Single Atoms on MXene for Enhanced Hydrogen Evolution Reaction

Precise anchoring and high-density utilization of platinum single atoms (Pt SA ) remain critical challenges in advancing efficient hydrogen production via water electrolysis. Here, we present an innovative magnetic-field-assisted electrodeposition strategy for the controllable synthesis of high-density Pt SA on two-dimensional MXene substrates. Application of a 0.6 T magnetic field significantly enhanced Pt SA deposition kinetics, yielding a 2.1-fold increase in the deposition rate. Numerical simulations confirmed that magnetohydrodynamic (MHD) effects induced by the magnetic field were the primary mechanism driving this enhanced deposition efficiency. The optimized Pt SA -0.6@MXene/NF catalyst exhibited outstanding hydrogen evolution reaction (HER) performance in 1 M KOH, achieving an ultralow overpotential of 12 mV at 10 mA cm −2 , along with a Tafel slope of 29 mV dec −1 . Notably, the catalyst demonstrated 66.1-fold higher Pt mass activity (3458.7 A g −1 ) compared to commercial Pt/C (52.3 A g −1 ) at a 50 mV overpotential. Density functional theory (DFT) calculations revealed that the high-density Pt SA configuration synergistically enhances MXene's electrical conductivity while lowering the d-band center, thereby optimizing the energy barrier for hydrogen intermediate (H*) adsorption. This work provides a novel strategy for regulating the magnetic-field-assisted deposition of Pt SA catalysts, offering a new avenue for designing high-performance water electrolysis catalysts.