Surpassing Pt hydrogen production from {200} facet-riched polyhedral Rh2P nanoparticles by one-step synthesis

The efficient water electrolysis catalyst is prominently important and urgent to forward the widespread appli-cations of hydrogen energy. In this work, polyhedral-morphology controlled rhodium phosphide (Rh2P) nano -particles are synthesized by one-step high temperature pyrolysis under Ar atmosphere at 90 Pa. By analyzing the morphologies of Rh2P, the crystal facets of {200}, {220} and {111} are dominant in the 26-facet polyhedrons, and {200} facets account for 58% of the total surface area of polyhedral 26-facet shapes. The overpotentials of polyhedral Rh2P NPs are 12.6 mV and 10.5 mV at 10 mA m- 2 in 0.5 M H2SO4 and 1 M KOH electrolytes, even lower than those of Pt/C. Theoretical calculations indicate that {200} facets of Rh2P NPs have the highest catalytic activity among {200}, {111}, and {220}, with the lowest hydrogen adsorption free energy. The sub-stantial exposure of {200} facets is beneficial to the high catalytic activity of Rh2P NPs.

Automated summary

Polyhedral-morphology controlled rhodium phosphide (Rh2P) nano-particles with dominant {200} facets exhibit high catalytic activity in water electrolysis, even superior to Pt/C catalyst. The exposure of {200} facets is advantageous for the catalytic performance of Rh2P NPs.