Simple fabrication of AuPd@Pd core-shell nanocrystals for effective catalytic reduction of hexavalent chromium

Abstract Herein, we developed a facile one-pot wet-chemical coreduction method for synthesis of core-shell AuPd@Pd nanocrystals (AuPd@Pd NCs), using polyvinylpyrrolidone (PVP) and minoxidil as the dispersing and growth-directing agents, respectively. The fabricated nanocrystals were mainly characterized by transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) in details. The architectures were explored for the catalytic reduction of Cr(VI) to Cr(III) by employing formic acid (HCOOH) as the reducing agent, showing enhanced catalytic activity of AuPd@Pd NCs in contrast with commercial Pd black catalyst. Additionally, the formation mechanism of AuPd@Pd NCs and the catalytic reduction mechanism of Cr(VI) were illustrated and discussed in some detail, respectively.