Browsing by Author "Sher, F."

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    Electronic and structural modification of three-dimensional porous NiCo@NF as a robust electrocatalyst for CO2 emission-free methanol upgradation to boost hydrogen co-production
    (American Chemical Society Publications, 2023-09-08) Arshad, F.; Tahir, A.; Haq, T.; Duran, Hatice; Hussain, I.; Sher, F.
    Electrochemical hydrogen evolution reaction (HER) coupled with methanol oxidation reaction (MOR) is an innovative process to attain energy-efficient hydrogen generation with more valuable formate product co-generation. Herein, we present 3D porous bimetallic NiCo nanostructures with oxygen vacancies grown on a nickel foam surface (Ov-NiCo@NF) as efficient electrocatalysts that show integrated highly selective methanol oxidation along with hydrogen evolution. The electronic structure of Ov-NiCo@NF is tuned by surface oxygen vacancies that provide a high active surface area and optimum chemisorption energy for selective methanol upgradation to formate. The metallic porous nanostructures and interconnected dendritic growth of nanoparticles ensure electrolyte penetration, with faster gas release ability, that enhances charge transfer kinetics and suppresses support passivation during MOR and HER. The 3D porous Ov-NiCo@NF exhibits improved methanol conversion activity, requiring 1.30 and 1.42 V (vs RHE) to achieve 50 and 100 mA cm-2 current densities for MOR, respectively. Furthermore, an integrated two electrode setup (Ov-NiCo@NF//Ov-NiCo@NF) requires a cell voltage of 1.41 V to attain 25 mA cm-2 current density for methanol-upgrading-assisted water electrolysis, while a higher cell voltage (1.62 V) is required in the electrolyte without methanol (overall water splitting). © 2023 American Chemical Society.
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    Fabrication of NiCu interconnected porous nanostructures for highly selective methanol oxidation coupled with hydrogen evolution reaction
    (Elsevier, 2022-01-15) Arshad, F.; Tahir, A.; Haq, T.; Duran, Hatice; Hussain, I.; Sher, F.
    Electrocatalytic water electrolysis is the most promising clean and efficient process for pure and clean generation of hydrogen. However, water oxidation reaction requires a large overpotential owing to its slow kinetics, causing a lower efficiency of hydrogen production and high energy consumption. Herein, we report the bimetallic NiCu interconnected porous nanostructures on copper foil (NiCu@Cu) prepared by hydrogen bubbles templating electrodeposition technique for methanol oxidation reaction (MOR), which replaces the kinetically sluggish water oxidation reaction and enhances the hydrogen production with lower energy input. With their high macroporosity, interconnected growth on copper foil with excellent conductivity and easy flow of electrolyte on electrode interface, and stabilization of active sites due to bimetallic synergistic effects, the NiCu@Cu electrocatalysts exhibit outstanding activities for HER and MOR. The NiCu@Cu requiring just 1.32 V anodic potential vs RHE at 10 mA cm−2 for MOR which is significantly lower than that for water oxidation reaction. Moreover, the electrolyzer using NiCu@Cu/NiCu@Cu for anodic MOR and cathodic H2 production only needs a low input voltage of 1.45 V to deliver a current density of 10 mA cm−2 with impressive durability.