Self-terminating electrodeposition of Pt on WC electrocatalysts.

ABSTRACT: Self-terminated electrochemical deposition is used to grow Pt nanoparticles on tungsten monocarbide (WC) from a pH 4 electrolyte of 3 mmol/L K2PtCl4-0.5 mol/L NaCl. An unconventional potentiodynamic deposition program is used where nucleation is promoted at large overpotentials followed by growth termination at still larger overpotentials to yield a high coverage of Pt nanoparticles. Following three deposition cycles between -0.8 VSCE and -0.45 VSCE, the surface is covered by a monolayer equivalent charge of Pt in the form of ≈3 × 1011 particles/cm2 that are ≈6.7 ± 1.1 nm in diameter. The number and size of nanoparticles increase monotonically for five deposition cycles. Area-normalized kinetics for hydrogen evolution (HER) and oxidation (HOR) on Pt-WC were determined in 0.5 mol/L H2SO4. F

SUBMITTER: Liu Y 

PROVIDER: S-EPMC7724966 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature