Interfacial Electronic Modulation on Nickel Cobaltite/Black Phosphorus Heterostructures for Boosting the Electrocatalytic Oxygen Evolution Reaction

Black phosphorus (BP) is always regarded as a potential electrocatalyst for the oxygen evolution reaction (OER) due to its extremely high carrier mobility and tunable electronic structure. However, the instability and poor intrinsic activity under ambient conditions greatly limit the further improvement of its OER performance. Herein, by coupling BP with nickel cobaltite with the aid of dry ball-milling, nickel cobaltite/BP (NCO/BP) heterostructures were rationally designed for alkaline OER catalysis. The NCO/BP heterostructures with interfacial P–M and P–O–M (M = Ni or Co) bonds significantly promote interfacial electron transfer and balance the adsorption of oxygen-containing intermediates, thus enhancing the electrocatalytic OER performance. The NCO/BP heterostructure exhibits an ultra-low overpotential of 197 mV at a current density of 10 mA·cm–2 and good electrocatalytic stability in alkaline media. By combining in situ Raman and DFT calculation analyses, the Ni sites may be the main active sites, and the interfacial P–M and P–O–M (M = Ni or Co) bonds significantly play a positive role in improving the electrocatalytic OER activity. This work fully confirms that the construction of heterostructures for interfacial electron regulation is a very promising way to emerging BP-based electrocatalysts.