Ni(OH)2–Ag hybrid nanosheet array with ultralow Ag loading as a highly efficient and stable electrocatalyst for hydrogen evolution reaction.

The design and synthesis of high-performance catalysts for hydrogen evolution reaction (HER) is of significant importance for electrocatalysis reaction. In this study, 0D Ag nanoparticles were successfully loaded onto 2D Ni(OH)₂ nanosheets by a one-step hydrothermal method for enhancing the electrocatalytic ability. The special structure of Ni(OH)₂ with only 2 wt% Ag on 3D nickel foam (NF) exhibited a high surface area and excellent charge transfer channels. Furthermore, the synergistic effect as well as the transfer of electron density between Ag and Ni(OH)₂ contributed to a high HER activity. As a result, Ni(OH)₂–Ag/NF exhibited excellent HER performance with an overpotential of 89 mV to obtain a current of 10 mA cm⁻² in an alkaline electrolyte, 155 mV lower than that of Ni(OH)₂/NF. After 10 hours of stability test and more than 1000 cycles, negligible loss of the initial catalytic activity to drive a current density of 10 mA cm⁻² verified excellent stability during the alkaline HER process. This research provides a new idea to integrally construct ultralow noble metal catalysts with outstanding HER performance and results in new advances in the field of hydrogen evolution. [ABSTRACT FROM AUTHOR]