Integrated PtCo-Hierarchical Carbon Matrix Electrocatalyst for Efficient Hydrogen Evolution Reaction.

Pt-based catalysts are regarded as state-of-the-art electrocatalysts for producing clean hydrogen energy; however, their wide application is restricted by their low abundance, high cost, and poor stability. Herein, we report an integrated PtCo-hierarchical carbon matrix electrocatalyst (Pt/Co@NCNTs, PtCo@NCNTs, PtCo@NCNTs, and PtCo@NCNTs) that is developed using a thermally driven Co migration strategy forming alloy nanoparticles to achieve efficient hydrogen evolution reaction (HER). Benefiting from its electronic regulation effect and unique hierarchical hollow structure, the PtCo@NCNTs catalyst loaded with 11.5 wt % Pt exhibits superior catalytic performance and durability for HER compared with commercial 20 wt % Pt/C. Under both alkaline and acidic conditions, PtCo@NCNTs exhibits excellent HER activity with overpotentials of 21 and 45 mV at 10 mA cm, respectively. Density functional theory (DFT) results further verify that the interaction between Pt and Co in PtCo@NCNTs can modulate electronic rearrangement, optimize the d-band center, and accelerate water dissociation and *H desorption, thereby enhancing HER activity.