Ir-modulated NiCoS/NiCoO p–n heterojunction nanocages with intensified built-in electric field for the accelerated oxygen evolution reaction

Abstract

A hollow Ir–NiCoS/NiCoO p–n heterojunction enables uniform Ir dispersion, doubling active surface area and reducing charge–transfer resistance by 63.9%, thus enhancing OER performance. As a result, the catalyst requires only 207 mV@10 mA cm⁻² and maintains stable operation at 50 mA cm⁻² for over 300 hours, demonstrating excellent activity and durability.