Combining High Porosity with High Surface Area in Flexible Interconnected Nanowire Meshes for Hydrogen Generation and Beyond

Tunable Magnetic Properties of Interconnected Permalloy Nanowire Networks

In this study, we investigate the magnetic properties of interconnected permalloy nanowire networks using micromagnetic simulations. The effects of interconnectivity on the hysteresis curves, coercivity, and remanence of the nanowire networks are analyzed. Our results reveal intriguing characteristics of the hysteresis curves, including nonmonotonic behaviors of coercivity as a function of the position of horizontal nanowires relative to vertical nanowires. By introducing horizontal nanowires at specific positions, the coercivity of the nanowire networks can be enhanced without altering the material composition. The normalized remanence remains relatively constant regardless of the position of the horizontal wires, although it is lower in the interconnected nanowire arrays compared to nonconnected arrays. These findings provide valuable insights into the design and optimization of nanowire networks for applications requiring tailored magnetic properties.

Revisiting anodic alumina templates: from fabrication to applications

Anodic porous alumina, -AAO- (also known as nanoporous alumina, nanohole alumina arrays, -NAA- or nanoporous anodized alumina platforms, -NAAP-) has opened new opportunities in a wide range of fields, and is used as an advanced photonic structure for applications in structural coloration and advanced optical biosensing based on the ordered nanoporous structure obtained and as a template to grow nanowires or nanotubes of different materials giving rise to metamaterials with tailored properties. Therefore, understanding the structure of nanoporous anodic alumina templates and knowing how they are fabricated provide a tool for the further design of structures based on them, such as 3D nanoporous structures developed recently. In this work, we review the latest developments related to nanoporous alumina, which is currently a very active field, to provide a solid and thorough reference for all interested experts, both in academia and industry, on these nanostructured and highly useful structures. We present an overview of theories on the formation of pores and self-ordering in alumina, paying special attention to those presented in recent years, and different nanostructures that have been developed recently. Therefore, a wide variety of architectures, ranging from ordered nanoporous structures to diameter changing pores, branched pores, and 3D nanostructures will be discussed. Next, some of the most relevant results using different nanostructured morphologies as templates for the growth of different materials with novel properties and reduced dimensionality in magnetism, thermoelectricity, etc. will be summarised, showing how these structures have influenced the state of the art in a wide variety of fields. Finally, a review on how these anodic aluminium membranes are used as platforms for different applications combined with optical techniques, together with principles behind these applications will be presented, in addition to a hint on the future applications of these versatile nanomaterials. In summary, this review is focused on the most recent developments, without neglecting the basis and older studies that have led the way to these findings. Thus, it gives an updated state-of-the-art review that should be useful not only for experts in the field, but also for non-specialists, helping them to gain a broad understanding of the importance of anodic porous alumina, and most probably, endow them with new ideas for its use in fields of interest or even developing the anodization technique.

A High-Surface-Area Carbon-Coated 3D Nickel Nanomesh for Li-O2 Batteries

Nanostructured electrodes show great promises for application in batteries and could improve their energy and power density. Herein, a carbon-coated 3D Ni nanomesh was used as an air cathode for non-aqueous Li-air (O₂ ) battery applications. A 3 μm thick 3D Ni nanomesh was fabricated, showing an excellent surface area/footprint area ratio (90 cm² :1 cm² ) and uniformly distributed pores, on which a conformal amorphous carbon coating was applied for the first time. This carbon-coated 3D Ni nanomesh showed an approximately 100 times larger charge-footprint capacity than that of the glassy carbon electrode. Owing to its tunable properties, a capacity higher than 6 mAh cm^-2 could be achieved for a carbon-coated 3D Ni nanomesh with a thickness of 100 μm, whereas the practical capacities of current air electrodes are in the range of 2 mAh cm^-2 .