Tunable synthesis of highly branched Pd nanodendrites for enhanced electrocatalysis

Abstract

Hierarchical porous noble-metal based structures are of great interest for energy electrocatalysis on account of their unique shape which not only provides high accessible surface area and consequently numerous catalytic active sites but also facilitates mass transport for rapid kinetics.We report a wet chemical approach to synthesize highly branched Pd nanodendrites with tunable sizes ranging from 25 to 125 nm via sequential oriented attachment growth and epitaxial growth. With the merits of mesoporous structure, atomic steps and corners, and grain boundaries, the 25 nm Pd nanodendrites deliver peak current density of 1625.5 mA mg−1Pd toward formic acid oxidation, the highest value among all reported branched Pd nanostructures, and exhibit half-wave potential of 0.882 V (vs. RHE) for the oxygen reduction reaction, 25 mV more positive than the Commercial Pt/C. The synthetic strategy demonstrated in this work can be further extended to create advanced nanocrystals for broad applications, such as in energy and biosensing systems and surface-enhanced Raman scattering.