Interface engineering of core-shell NiSe/NiTe electrocatalyst for enhanced oxygen evolution and urea oxidation reactions.

The development of highly efficient oxygen evolution reaction (OER) and urea oxidation reaction (UOR) electrocatalysts with abundant resources is necessary for green hydrogen production. Ni-based compounds have received attention as the most promising earth-abundant electrocatalysts for OER and UOR, whereas some compounds in this main group, e.g., nickel selenides and tellurides, have received little attention. Herein, we demonstrate the interfacial engineered NiSe/NiTe array on Ni foam as a highly efficient catalyst for the OER, which exhibits an overpotential of 200 mV to obtain a current density of 10 mA cm in alkaline solutions. Meanwhile, it exhibits a low potential of 1.301 V for the UOR at a current density of 100 mA cm. In particular, it even has the potential to be used in methanol oxidation reaction and ethanol oxidation reaction. The vertical NiTe array not only serves as the conductive substrate for highly improving the mass loading of NiSe, but also triggers the strong electron interaction between two components, leading to increased adsorption sites available for the intermediates formed in the OER and UOR on the NiSe surface. This study provides a broad avenue to construct hierarchical nanostructures as outstanding electrocatalysts for efficient OER and UOR.