Crystalline-amorphous heterostructures with assortative strong-weak adsorption pairs enable extremely high water oxidation capability toward multi-scenario water electrolysis

Nano-sized crystalline-amorphous heterostructures display prominent catalytic activity toward multifarious electrochemical reactions, while no rational component selection strategy could be provided hitherto. Herein, an accurate tactic by introducing assortative strong-weak Ru-Co adsorptive atomic pair into the construction of hollow Ru-CoMoSx nanotube arrays is first proposed. Benefiting from the favorable charge density redistribution and adjusted d-band centers over the coupling strong-weak Ru-Co adsorption sites, balanced adsorption behaviors can be achieved upon potential active centers, thereby leading to the very low reaction energy barriers. Indeed, due to the anticipatory strong-weak Ru-Co adsorption pair, the as-constructed crystalline-amorphous Ru-CoMoSx heterointerface affords one of the best electrocatalytic activity toward oxygen evolution reaction (OER) in alkaline media to date, with an extremely low overpotential of 147 mV at the current density of 10 mA cm−2. Also, it exhibits an admirable Pt-like hydrogen evolution (HER) behavior (35 mV @ 10 mA cm−2). Thereout, its application prospect in practical multi-scenario water electrolysis, including freshwater/seawater electrolysis and integrated photovoltaics-hydrogen production system, is well demonstrated. This work provides instructive guidance for the rational design and in-depth structure-activity analysis of nano-sized crystalline-amorphous heterostructures.