One-pot synthesis of hollow AgPt alloyed nanocrystals with enhanced electrocatalytic activity for hydrogen evolution...

Herein, a simple one-pot aqueous method was developed for the fabrication of uniform hollow bimetallic AgPt alloyed nanocrystals (H-AgPt NCs) by using 5-aminoorotic acid (5-amino-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid) as a growth-directing agent, without any seed, organic solvent or template involved. The prepared H-AgPt NCs displayed enhanced electrocatalytic activity for hydrogen evolution reaction (HER) with a more positive onset overpotential (η_onset) of -28mV and a smaller Tafel slope of 40mVdec^-1 relative to commercial Pt black (-34mV, 50mVdec^-1) and Pt/C (20wt.%, -33mV, 33mVdec^-1) in 0.5M H₂SO₄. Meanwhile, the obtained catalyst exhibited improved catalytic features toward oxygen reduction reaction (ORR) with a positive η_onset (0.916V) and enhanced kinetic current density (243.23mAmg^-1_Pt) in 0.1M HClO₄ at 0.850V compared with Pt black (0.876V, 25.85mAmg^-1_Pt).