Electrochemically Oxidized Aligned Carbon Nanotube Arrays Embedding Foam Substrates for Water Splitting

Abstract

Designing highly active electrocatalysts for both hydrogen and oxygen evolution with good durability at large current densities is very significant for water splitting. In this study, a new type of catalytic electrode was developed for water splitting. This electrode was made by growing microflower-like NiFeP on an aligned carbon nanotube (CNT) array network skeleton that was embedded in a Ni foam (NF) substrate. This design is aimed at enhancing the electrocatalytic activity for both hydrogen and oxygen evolution. The results showed that the resulting electrode (ECO-NF-ACNT@NiFeP) had a porous structure and was hydrophilic and highly resistant to corrosion, leading to improved activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The overpotential for harvesting a 10 mA cm −2 OER and HER current density was 97 and 190 mV, respectively, and the overpotential for reaching 100 mA cm −2 was 345 and 348 mV, respectively. These results are significantly better than those of commercial RuO 2 and Pt/C catalysts and provide a promising direction for developing water splitting catalysts.

Amorphous Co–Mo–P film on nickel foam: a superior bifunctional electrocatalyst for alkaline seawater splitting

“…Given the advantages of 3D nickel foam (NF) including high electrical conductivity, large surface area, and the ability to be loaded by a high quantity of catalyst [31], an amorphous bifunctional electrocatalyst Co-Mo-P film supported on NF (Co-Mo-P/NF) is synthesized which could behave with high-efficiency and durable catalytic activity towards alkaline seawater splitting. The amorphous feature can reveal more active reaction sites and regulate the intrinsic activity of Co-Mo-P/NF through the affiliation of high-valence Mo.…”

Hierarchical Design of Homologous NiCoP/NF from Layered Double Hydroxides as a Long-Term Stable Electrocatalyst for Hydrogen Evolution

“…By controlling the reaction temperature of the two-step hydrothermal reaction, the optimal growth orientation of the crystal can be effectively controlled, and the addition of morphology regulators can also effectively adjust the micromorphology of the material. The composite 3D nanostructures of nanowires (NWs) [27,28], nanosheets (NSs) [29][30][31], nanotubes (NTs) [32][33][34], and layered double hydroxide (LDH) nanosheets, such as "wire-on-sheet" [35,36], "sheet-on-sheet" [37][38][39] and "sheet-on-tube" [40,41] can effectively combine the HER properties of the active sites in different components and enhance the stability of the electrode [42][43][44]. These establishments of hierarchical structures can leverage the combined advantages of different structures, accelerate the mass and charge transfer rate of materials and improve the mechanical stability and flexibility of materials.…”