Boosting the oxygen evolution electrocatalysis of high-entropy hydroxides by high-valence nickel species regulation

The addition of an extra metal source induces the transformation from crystalline alpha-Ni(OH)(2) to an amorphous NiCoFeCrMo-based high-entropy hydroxide (HEH) and maximizes the high-valence Ni3+ content in HEH. For OER electrocatalysis, the quinary HEH possesses an overpotential of 292 mV at 10 mA cm(-2), a Tafel slope of 54.31 mV dec(-1) and the boosted intrinsic activity, surpassing other subsystems.

Automated summary

The addition of an extra metal source leads to the transformation from crystalline alpha-Ni(OH)(2) to an amorphous NiCoFeCrMo-based high-entropy hydroxide (HEH), increasing the content of high-valence Ni3+ in HEH. For OER electrocatalysis, the quinary HEH exhibits a lower overpotential, a smaller Tafel slope, and enhanced intrinsic activity compared to other subsystems.