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

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.