Comparison of Modifications for Enhancing the Electrooxidation Performance of Porous Ni Foil Catalytic Electrodes Derived from Paper Templates: Cu-Added Alloying and In Situ Growth of Ni-S Nanosheets

Improving the performance of porous nickel-based material used widely in the energy field is necessary. Alloying and increasing the specific surface area are essential approaches. This study used rice paper (Chinese traditional calligraphy and painting paper) as biomass templates to prepare hierarchical porous Ni and Ni-Cu foils (Nip and NiCup) with a thickness of about 60 μm by impregnating and high-temperature reduction process. The Ni3S2/Nip electrodes were prepared by an in situ-grown Ni3S2 nanosheet array on the struts of Nip via a hydrothermal process. Two modification methods using Cu-added alloying and Ni-S nanosheet growing were compared to determine their effects on the microstructure, phase, and performance in methanol oxidation (MOR) and urea oxidation (UOR). The results showed that both alloying effects and morphology control can promote MOR and UOR. Compared to the current density value of Nip at 0.8 V, the values of the preferred Ni10Cup and nanosheet array Ni3S2/Nip increased by 24.5