Precisely Controlled Synthesis of Hybrid Intermetallic–Metal Nanoparticles for Nitrate Electroreduction

Precisely controlled synthesis strategies to prepare anisotropic nanomaterials with high yield and easy operation are exceedingly in demand because hybrid structures often introduce novel properties that cannot be achieved by isotropic nanomaterials. Here, a one-pot, two-step hot injection method was developed to prepare Cu6Sn5–Sn hybrid intermetallic–metal nanoparticles with an anisotropic structure. Hybrid nanoparticles with distinguishable Sn and Cu6Sn5 domains were formed under mild temperature. Different compositions of Sn and Cu6Sn5, ranging from pure Sn to various ratios of the Sn part and Cu6Sn5 part to pure Cu6Sn5, were achieved by modulating the reaction conditions, the ratio of the two metals. The as-synthesized asymmetric Cu6Sn5–Sn nanoparticles show small onset potentials (0.2 V vs reversible hydrogen electrode, RHE) and high activities (1125 mA mg–1metal at −0.2 V vs RHE) in electrocatalytic nitrate reduction reaction. Unlike reported Cu- or Sn-based catalysts in nitrate reduction, the hybrid Cu6Sn5–Sn nanoparticles selectively produce the unstable intermediate, nitrite, within a wide reduction potential window.