Pressure-promoted irregular CoMoP2 nanoparticles activated by surface reconstruction for oxygen evolution reaction electrocatalysts

Developing highly ordered and conductive phosphorous-based materials and identifying their active sites are critical to improve the catalytic performance for oxygen evolution reactions (OERs). Herein, we report a template-free and rapid high-pressure synthesis protocol to fabricate irregular CoMoP2 nanoparticles for OER catalysts. Pure CoMoP2 electrocatalysts show a reduced overpotential of 270 mV at 10 mA cm−2, improved kinetics and long-term stability. XAS, XPS and DFT calculations reveal that the reorganization induces highly active Co sites with a Co(OH)2 layer on the surface, while Mo atoms regulate electronic conductivity towards OER reduction potential and maintain the structural integrity of CoMoP2. This work not only provides an identified activation mechanism for bimetallic catalysts, but also highlights the high-pressure synthesis as one of the alternative approaches for developing OER catalysts.