Structural and Electrochemical Insights into Pt65Cu35 Alloy for Enhanced HER Performance
Keywords:
Polyol Method, SEM-EDS, XRD, Hydrogen evolution reaction, PtCu nanoparticleAbstract
This study presents a comprehensive structural and electrochemical characterization of Pt65Cu35 alloy nanoparticles (NPs) for their application in the hydrogen evolution reaction (HER). X-ray diffraction method have been used to determine structural properties and revealed a well-defined crystal structure corresponding to the face-centered-cubic (fcc) Pt3Cu1 alloy phase, evidenced by characteristic Miller indices as the (111), (200), (220), (311), and (222) planes. Further examination yielded a uniform lattice constants of 3.923 Å, indicating a homogeneous crystal lattice. Assessment of crystallite size, 2.9 nm, and microstrain, 3.85%, underscored the influence of PtCu alloy formation on structural defects and grain boundaries within the NPs. The stoichiometric calculation via energy-dispersive X-ray spectroscopy confirmed Pt and Cu ratio with a percentage of 65 and 35 in the structure and scanning electron microscope showed a spherical morphology attributed to the influence of polyvinylpyrrolidone molecules during synthesis. Moreover, electrochemical investigations revealed promising HER catalytic performance, with cyclic voltammetry (CV) analyses demonstrating Pt-H formation followed by H2 gas formation. Linear sweep voltammetry (LSV) analysis confirmed a maximum current density of 1.52 mA cm-2 was achieved at -0.37 V, indicating high catalytic activity. Furthermore, CV curves recorded over 500 cycles elucidated cyclic behavior, with a current density of 3.04 mA cm-2 gradually decreasing over subsequent cycles before stabilizing beyond the 100th cycle. These findings underscore the exceptional electrocatalytic performance of Pt65Cu35 catalysts, highlighting their potential for various electrochemical applications. Further research avenues may focus on elucidating underlying mechanisms governing cyclic behavior to optimize catalyst design for enhanced performance and durability.