One-pot synthesis of hollow AgPt alloyed nanocrystals with enhanced electrocatalytic activity for hydrogen evolution and oxygen reduction reactions

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-tetrahy dropyrimidine-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 (eta(onsa)) of-28 mV and a smaller Tafel slope of 40 mV dec(-1) relative to commercial Pt black (-34 mV, 50 mV dec(-1)) and Pt/C (20 wt.%, -33 mV, 33 mV dec(-1)) in 0.5 M H2SO4. Meanwhile, the obtained catalyst exhibited improved catalytic features toward oxygen reduction reaction (ORR) with a positive eta(onset) (0.916 V) and enhanced kinetic current density (243.23 mA mg(pt)(-1)) in 0.1 M HClO4 at 0.850 V compared with Pt black (0.876 V, 25.85 mA mg(pt)(-1)). 2017 Elsevier Inc. All rights reserved.