Boosting Hydrogen Evolution through the Interface Effects of Amorphous NiMoO4–MoO2 and Crystalline Cu

The rational design and synthesis of a highly efficient and cost-effective electrocatalyst for hydrogen evolution reaction (HER) are of great importance for the efficient generation of sustainable energy. Herein, amorphous/crystalline heterophase Ni–Mo–O/Cu (denoted as a/c Ni–Mo–O/Cu) was synthesized by a one-pot electrodeposition method. Thanks to the introduction of metallic Cu and the formation of amorphous Ni–Mo–O, the prepared electrocatalyst exhibits favorable conductivity and abundant active sites, which are favorable to the HER progress. Moreover, the interfaces consisting of Cu and Ni–Mo–O show electron transfers between these components, which might modify the absorption/desorption energy of H atoms, thus accelerating HER activity. As expected, the prepared a/c Ni–Mo–O/Cu possesses excellent HER performance, which affords an ultralow overpotential of 34.8 mV at 10 mA cm–2, comparable to that of 20 wt % Pt/C (35.0 mV), and remarkable stability under alkaline conditions.