Carbon-Nanoplated CoS@TiO₂ Nanofibrous Membrane: An Interface-Engineered Heterojunction for High-Efficiency...

Developing noble-metal-free electrocatalysts is important to industrially viable ammonia synthesis through the nitrogen reduction reaction (NRR). However, the present transition-metal electrocatalysts still suffer from low activity and Faradaic efficiency due to poor interfacial reaction kinetics. Herein, an interface-engineered heterojunction, composed of CoS nanosheets anchored on a TiO₂ nanofibrous membrane, is developed. The TiO₂ nanofibrous membrane can uniformly confine the CoS nanosheets against agglomeration, and contribute substantially to the NRR performance. The intimate coupling between CoS and TiO₂ enables easy charge transfer, resulting in fast reaction kinetics at the heterointerface. The conductivity and structural integrity of the heterojunction are further enhanced by carbon nanoplating. The resulting C@CoS@TiO₂ electrocatalyst achieves a high ammonia yield (8.09×10^-10  mol s^-1  cm^-2 ) and Faradaic efficiency (28.6 %), as well as long-term durability.