Bismuth‐Noble Metal Alloy Nanostructures Prepared by Colloidal Chemical Routes for Use in Hydrogen Evolution and Oxygen Reduction Electrocatalysis: Bi‐Pt Versus Bi‐Pd

Abstract Compositional and morphological tuning of bismuth‐based nanomaterials is crucial to improve and broaden the application of such structures in a range of electrocatalytic reactions. Nanostructures composed of Pt‐Bi and Pd‐Bi alloys in different elemental proportions and shapes are produced by solvothermal and hydrothermal chemical routes at moderate temperatures. The alloying of cost‐effective bismuth with platinum is found to be much more efficient than that with palladium for the boosting of the hydrogen evolution reaction (HER) and the oxygen reduction reaction (ORR). Interestingly, Pt‐rich Pt‐Bi structures with irregular‐shaped thin morphologies are more suitable for HER, whereas cubic‐like Pt‐Bi nanostructures prove to be better catalysts for the ORR. The higher mass activity of Pt‐Bi alloys in ORR than that of pure Bi and Pd‐Bi alloys as well as the low HER overpotentials, which are comparable with benchmark 10% Pt/C catalysts, are attributed to synergistic effects, due to the coexistence and satisfactory degree of alloying between both metals.