Earthing-Inspired Nanoparticle-Filled Nanosheet Arrays for Robust and Efficient Electrochemical Gas Evolution...

Industrial-scale gas evolution reactions (GERs) are central to energy conversion and storage technologies, yet are often hindered by catalyst delamination and performance degradation caused by rapid and continuous bubble detachment under high current densities. Inspired by earthing-up in agriculture, a moderately nanoparticle-filled nanosheet array architecture is reported, constructed via a phosphorization-controlled confined-growth strategy, that achieves dual interfacial optimization through nanoparticle-nanosheet cooperativity. Experimental and finite element simulations reveal that electrolyte flow induced by bubble destabilization within the nanosheet voids facilitates efficient gas release, thereby reducing electrocatalyst-bubble interfacial adhesion force. Simultaneously, embedded nanoparticles with larger critical buckling forces enhance the structural rigidity of the nanosheet arrays, significantly strengthening the electrocatalyst-support interfacial binding force. When applied as the electrocatalyst for oxygen evolution reaction (OER), the resulting electrode exhibits a low overpotential of 256 mV at 1000 mA cm^-2 and maintains stable operation for 2400 h, which ranks among the best reported for OER electrocatalysts under high-current densities. Likewise, this design strategy can be universally extended to other GERs, including hydrogen evolution reaction, urea oxidation reaction, and hydrazine oxidation reaction. This work underscores the potential of nanoparticle-filled nanoarchitectures in optimizing interfacial mechanics and advancing durable, high-performance electrocatalysts for GERs.