Phosphorus–nitrogen Co-doped 3D RuCo spheres on activated carbon cloth with enhanced electrocatalytic activity for hydrogen and oxygen evolution reactions

Developing cost-effective and efficient electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for advancing sustainable energy technologies. Herein, we introduce phosphorus-nitrogen (P–N) co-doped RuCo alloy nanospheres supported on 3D carbon cloth (PN–RuCo/CC) as a bifunctional electrocatalyst for HER and OER. The synergistic effects of Ru–Co alloying, P and N co-doping, and the 3D carbon cloth support significantly enhance catalytic efficiency by optimizing the electronic structure, facilitating charge redistribution, and increasing active site exposure. Consequently, PN-RuCo/CC exhibits low overpotentials of 30 mV for HER and 232 mV for OER at 10 mA cm⁻², along with excellent stability. Furthermore, when employed in a symmetric overall water-splitting (OWS) cell, it achieves 1.61 V at 10 mA cm⁻², demonstrating superior bifunctional electrocatalytic performance. These findings establish PN-RuCo/CC as a highly efficient and durable bifunctional catalyst, paving the way for its integration into advanced water-splitting and renewable energy systems.