Monolayered Platinum Nanoparticles as Efficient Electrocatalysts for the Mass Production of Electrolyzed Hydrogen Water.

ABSTRACT: High-performance/low-cost platinum (Pt)-based electrocatalysts have been established by top-coating both sides of a titanium plate with Pt nanoparticles. The average diameter of the Pt nanoparticles used in this study is approximately 100?nm. Three types of Pt top-coated Pt/Ti electrocatalysts, each having different top-coated Pt layer thicknesses, are prepared. Type I is a monolayered Pt top-coated type, in which the thickness of the top-coated Pt layer is approximately 100?nm; Type II is a few-layered type with a top-coated Pt layer thickness of approximately 200?nm, and Type III is a multilayered type with a top-coated Pt layer thickness of approximately 750?nm. The mass loading of Pt is 0.0215?mg?cm^-2 for Type I, 0.043?mg?cm^-2 for Type II, and 0.161?mg?cm^-2 for Type III. The electrocatalytic activities of each type of Pt/Ti electrocatalyst are evaluated through the electrolysis of acidic water and tap water. Type I gives the highest electrocatalytic efficiencies, which are comparable or even better than the electrocatalytic efficiencies of the state-of-the-art commercially available Pt/C electrode and other metal-/carbon-based HER catalysts. For example, in the case of the electrolysis of acidic water at an overpotential of 0.15?V, Type I shows a Tafel slope of 29?mV dec^-1 and a current density of 27.5?mA?cm^-2. Even in the case of the electrolysis of tap water, Type I gives an HER Faradaic efficiency of 92%. A model of water (H₂O), hydronium ions (H₃O⁺), and hydroxyl ions (OH^-) properly adsorbing on the Pt (111) facet is proposed to explain the electrocatalytic mechanism. New insights into the distinguishing properties of the resultant electrolyzed hydrogen water (EHW), namely, the healthy beneficial effects of EHW, are also described, and a new concept of storing and carrying reductive hydrogen (H*) by free Pt nanoparticles is proposed.

SUBMITTER: Wang Y 

PROVIDER: S-EPMC7311417 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature