Optimization of gold-palladium core-shell nanowires towards H₂O₂ reduction by adjusting shell thickness

Designable bimetallic core-shell nanoparticles exhibit superb performance in many fields including industrial catalysis, energy conversion and chemical sensing, due to their outstanding properties associated with their tunable electronic structure. Herein, Au-Pd core-shell (Au_richPd@AuPd_rich) nanowires (NWs) were synthesized through a one-pot facile chemical reduction method in the presence of cetyltrimethyl ammonium bromide (CTAB) surfactant. The thickness of the Pd shell could be adjusted by directly controlling the Au/Pd feeding ratio while maintaining the nanowire morphology. The as-obtained Au₇₅Pd₂₅ core-shell NWs with a thin Pd_rich shell showed significantly enhanced activities towards the reduction of hydrogen peroxide with the sensitivity reaching 338 μA cm^-2 mM^-1 and a linear range up to 10 mM. In sum, Pd shell thickness could be used to adjust the electronic structure, thereby optimizing the catalytic activity.