Pt quantum dots coupled with NiFe LDH nanosheets for efficient hydrogen evolution reaction at industrial current densities

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Developing efficient and economical electrocatalysts for hydrogen generation at high current densities is crucial for advancing energy sustainability. Herein, a self-supported hydrogen evolution reaction (HER) electrocatalyst is rationally designed and prepared on a nickel foam through a simple two-step chemical etching method, which consists of Pt quantum dots (PtQDs) coupled with nickel-iron layered double hydroxide (NiFe LDH) nanosheets (named PtQDs@NiFe LDH). The characterization results indicate that the introduction of PtQDs induces more oxygen vacancies, thereby optimizing the electronic structure of PtQDs@NiFe LDH. This modification enhances the conductivity and accelerates the adsorption/desorption kinetics of hydrogen intermediates in PtQDs@NiFe LDH, ultimately resulting in exceptional catalytic performance for the HER at large current densities. Specifically, PtQDs@NiFe LDH delivers 500 and 2000 mA·cm-2 with remarkably low overpotentials of 92 and 252 mV, respectively, markedly outperforming commercial Pt/C (η500 = 190 mV, η2000 = 436 mV). Moreover, when employing NiFe LDH precursor and the prepared PtQDs@NiFe LDH catalyst as the anode and cathode, respectively, in an overall water electrolysis system, only 1.66 V and 2.02 V are required to achieve 500 and 2000 mA·cm-2, respectively, while maintaining robust stability for 200 h. This study introduces a feasible approach for developing HER electrocatalysts to achieve industrial-scale current densities.