Surface-engineered mesoporous Pt nanodendrites with Ni dopant for highly enhanced catalytic performance in hydrogen evolution reaction

Hydrogen production by electrolyzing water is expected to be one of the most effective strategies to realize the comprehensive utilization of clean energy and thus alleviate the growing environmental problems. Platinum is the most active electrochemical hydrogen evolution reaction (HER) catalyst so far, but the high cost of Pt limits its applications. Herein, we report the use of surface-engineered mesoporous Pt nanodendrites with Ni dopant to form PtNi/Pt DNPs, which were used to lower the Pt loading amount and improve the performance. The intrinsic catalytic activity of the dendritic nanoparticles (DNPs) was greatly enhanced by the incorporation of Ni atoms into Pt, which tuned the charge density and surface electronic structure to accelerate the reaction kinetics. Meanwhile, their relative catalytic activity was improved by constructing the 3D mesoporous dendritic structure, which largely enhanced the mass transfer in catalysts. The as-prepared PtNi/Pt DNPs presented a small overpotential of 21 mV at a current density of 10 mA cm^-2 in 0.5 M H₂SO₄, which was much lower than most of the reported Pt-based catalysts. In addition, it also exhibited an excellent durability and a current density of 128.3 mA cm^-2 at an overpotential of 0.05 V, which was over 6.46 times higher than the commercial Pt-JM NPs. Furthermore, the PtNi/Pt DNPs only showed an overpotential of 71 mV even though the current density reached 250 mA cm^-2 on the glassy carbon electrode, which was significantly better than those of the most reported noble metal and non-noble metal HER catalysts. This work not only developed a superior electrocatalyst for the HER, but also provided a guideline for the rational design of highly active and robust catalysts.