Annealing temperature dependent catalytic water oxidation activity of iron oxyhydroxide thin films

Nanostructured iron oxyhydroxide（Fe OOH） thin films have been synthesized using an electrodeposition method on a nickel foam（NF） substrate and effect of air annealing temperature on the catalytic performance is studied. The as-deposited and annealed thin films were characterized by X-ray diffraction（XRD）,X-ray photoelectron spectroscopy（XPS）, field emission scanning electron microscopy（FE-SEM） and linear sweep voltammetry（LSV） to determine their structural, morphological, compositional and electrochemical properties, respectively. The as-deposited nanostructured amorphous Fe OOH thin film is converted into a polycrystalline Fe;O;with hematite crystal structure at a high temperature. The Fe OOH thin film acts as an efficient electrocatalyst for the oxygen evolution reaction（OER） in an alkaline 1 M KOH electrolyte. The film annealed at 200 °C shows high catalytic activity with an onset overpotential of 240 m V with a smaller Tafel slope of 48 m V/dec. Additionally, it needs an overpotential of 290 mV to the drive the current density of 10 m A/cm;and shows good stability in the 1 M KOH electrolyte solution.

Two-dimensional PtRu Nanoclusters Carbon Based Electrocatalysts for Methanol Oxidation

A novel method to prepare an electrocatalyst with a new structure and high catalytic performance was reported. Two-dimensional（2 D） PtRu nanoclusters have been successfully deposited on graphene oxide and carbon black supports. Compared with the commercial 3 D E-TEK PtRu samples, the prepared 2 D PtRu composites have larger electrochemically active surface area and display much higher catalytic activity toward methanol oxidation reaction. The preparation method mainly includes the following procedures： oxidation of carbon matrix, Pb^（2＋） adsorption on the surface of carbon support, Pb^（2＋） electrochemical reduction and galvanic displacement of Pb^0 by Pt^（2＋） and Ru^（3＋）. The method developed in this study could be viable for solving the problem of low electrocatalytic activity in direct methanol fuel cell anodes.

One-pot synthesis of interconnected Pt95Co5 nanowires with enhanced electrocatalytic performance for methanol oxidation reaction

Shape- and composition-controlled synthesis of platinum-based nanocrystals （NCs） is critical for the development of electrocatalysts that have high activity toward the methanol oxidation reaction （MOR） in direct methanol fuel cells （DMFCs）. We report one-pot surfactant-free synthesis of interconnected PtgsCo5 nanowires （NWs） via an oriented attachment process, which has distinct advantages over conventional template- and surfactant-assisted approaches. Enhanced electrochemical activities toward MOR were confirmed through comparison with pure Pt NWs and commercial Pt/C catalyst. Pt95Co5 NWs demonstrated the highest current density during the long-term stability test. These results reveal that the introduction of the 3d-transition metal Co can reduce the catalyst cost and contribute to the improvement of electrochemical performance. The integrated design of interconnected NW structure, bimetallic composition, and clean surfaces in the present system may open a new way to the development of excellent electrocatalysts in DMFCs.