Alloying-Induced Synthesis of Amorphous PdZnS Hollow Spheres as Enhanced Oxygen Reduction Catalysts

Amorphous alloys have multiple advantages in electrocatalysis, yet the isotropic nature makes their syntheses a great obstacle in application. In this work, it is shown that the Zn²⁺ can interfere with the crystallization of Pd-base structures to form amorphous alloy materials. By simply adjusting the Zn²⁺ content, unique PdZnS amorphous hollow spheres (AHS) with various compositions and degrees of crystallinity can be obtained through a facile one-pot wet chemical method. Owing to both the amorphous nature and hollow morphologies, the PdZnS AHSs possess appealing activities and stabilities as oxygen reduction catalysts. Typically, the Pd₂₀ ZnS₁₀ AHSs exhibit the highest half-wave potential (E_1/2 ) of 0.940 V (vs reversible hydrogen electrode), and such E_1/2 only negatively shifts 25 mV after 60 000 cycles.