Facile solvothermal fabrication of PtNi nanopolyhedrons for greatly boosting electrocatalytic performances for oxygen reduction and hydrogen evolution.

Pt-based bimetallic nanostructures with low content of Pt were considered as one of the attractive nanocatalysts for their high Pt utilization efficiency, remarkable catalytic characters and cost-effectiveness in facilitating the sluggish cathodic reactions in fuel cells. Herein, three-dimensional PtNi nanopolyhedrons (NPHs) with abundant active sites were constructed by a facile one-pot solvothermal strategy, in which cytosine and cetyltrimethylammonium chloride (CTAC) worked as the co-structure directing agents. The PtNi NPHs were mainly characterized by a series of techniques, showing the high catalytic activity and stability towards oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) in comparison to PtNi nanocrystals (NCs), PtNi NCs, commercial Pt black and/or Pt/C catalysts. Impressively, the mass activity of PtNi NPHs was about 215.80 mA mg for ORR, approximately 4-time increase relative to Pt black (49.60 mA mg). These results demonstrate the promising applications of the synthesized nanocatalysts in energy storage and transformation.