Synthesis of Ni-WOx at Different H+ Concentrations for Hydrogen Evolution Reaction


 The development of efficient, durable, and inexpensive catalysts is a major challenge in achieving widespread application of hydrogen evolution reaction (HER). Herein, the Ni-WOx nanoparticles were prepared on nickel foam by hydrothermal and heat treatment. In particular, the nickel foam is not only used as a substrate, but also as a nickel source in an acidic environment to achieve the purpose of nickel doping. HCl is used to regulate the acidic environment, and its dosage will directly affect the phase and size of the material. By optimizing the usage of HCl, we demonstrate that the size of Ni-WOx nanoparticles decreased with the increase in HCl dosage. However, when the amount of HCl is too high, the nanoparticles will agglomerate and the crystalline phase of the material was also changed. When the usage of HCl is 300 µL, the optimized Ni-WOx has a smaller contact resistance and faster charge transfer rate, exhibiting excellent HER performance in alkaline media (the over-potentials is 96 mV at 20 mA cm-2 and outstanding durability over 10 h).