Synthesis of a single-crystal Fe2O3 nanowire array based on stress-induced atomic diffusion used for solar water splitting

Fabrication of γ-Fe2O3 Nanowires from Abundant and Low-cost Fe Plate for Highly Effective Electrocatalytic Water Splitting

Water splitting is thermodynamically uphill reaction, hence it cannot occur easily, and also highly complicated and challenging reaction in chemistry. In electrocatalytic water splitting, the combination of oxygen and hydrogen evolution reactions produces highly clean and sustainable hydrogen energy and which attracts research communities. Also, fabrication of highly active and low cost materials for water splitting is a major challenge. Therefore, in the present study, γ-Fe₂O₃ nanowires were fabricated from highly available and cost-effective iron plate without any chemical modifications/doping onto the surface of the working electrode with high current density. The fabricated nanowires achieved the current density of 10 mA/cm² at 1.88 V vs. RHE with the scan rate of 50 mV/sec. Stability measurements of the fabricated Fe₂O₃ nanowires were monitored up to 3275 sec with the current density of 9.6 mA/cm² at a constant potential of 1.7 V vs. RHE and scan rate of 50 mV/sec.

Hematite and Magnetite Nanostructures for Green and Sustainable Energy Harnessing and Environmental Pollution Control: A Review

The optoelectrical and magnetic characteristics of naturally existing iron-based nanostructures, especially hematite and magnetite nanoparticles (H-NPs and M-NPs), gained significant research interest in various applications, recently. The main purpose of this Review is to provide an overview of the utilization of H-NPs and M-NPs in various environmental remediation. Iron-based NPs are extensively explored to generate green energy from environmental friendly processes such as water splitting and CO₂ conversion to hydrogen and low molecular weight hydrocarbons, respectively. The latter part of the Review provided a critical overview to use H-NPs and M-NPs for the detection and decontamination of inorganic and organic contaminants to counter the environmental pollution and toxicity challenge, which could ensure environmental sustainability and hygiene. Some of the future perspectives are comprehensively presented in the final portion of the script, optimiztically, and it is supported by some relevant literature surveys to predict the possible routes of H-NPs and M-NPs modifications that could enable researchers to use these NPs in more advanced environmental applications. The literature collection and discussion on the critical assessment of reserving the environmental sustainability challenges provided in this Review will be useful not only for experienced researchers but also for novices in the field.

Synthesis of Iron Oxide Nanostructures via Carbothermal Reaction of Fe Microspheres Generated by Infrared Pulsed Laser Ablation

Iron oxide nanostructures were synthesized using the carbothermal reaction of Fe microspheres generated by infrared pulsed laser ablation. The Fe microspheres were successfully deposited on Si(100) substrates by laser ablation of the Fe metal target using Nd:YAG pulsed laser operating at λ = 1064 nm. By varying the deposition time (number of pulses), Fe microspheres can be prepared with sizes ranging from 400 nm to 10 µm. Carbothermal reaction of these microspheres at high temperatures results in the self-assembly of iron oxide nanostructures, which grow radially outward from the Fe surface. Nanoflakes appear to grow on small Fe microspheres, whereas nanowires with lengths up to 4.0 μm formed on the large Fe microspheres. Composition analyses indicate that the Fe microspheres were covered with an Fe3O4 thin layer, which converted into Fe2O3 nanowires under carbothermal reactions. The apparent radial or outward growth of Fe2O3 nanowires was attributed to the compressive stresses generated across the Fe/Fe3O4/Fe2O3 interfaces during the carbothermal heat treatment, which provides the chemical driving force for Fe diffusion. Based on these results, plausible thermodynamic and kinetic considerations of the driving force for the growth of Fe2O3 nanostructures were discussed.

Nanowire surface fastener fabrication on flexible substrate

The market for wearable devices has increased considerably in recent years. In response to this demand, flexible electronic circuit technology has become more important. The conventional bonding technology in electronic assembly depends on high-temperature processes such as reflow soldering, which result in undesired thermal damages and residual stress at a bonding interface. In addition, it exhibits poor compatibility with bendable or stretchable device applications. Therefore, there is an urgent requirement to attach electronic parts on printed circuit boards with good mechanical and electrical properties at room temperature. Nanowire surface fasteners (NSFs) are candidates for resolving these problems. This paper describes the fabrication of an NSF on a flexible substrate, which can be used for room temperature conductive bonding. The template method is used for preparing high-density nanowire arrays. A Cu thin film is layered on the template as the flexible substrate. After etching the template, a Cu NSF is obtained on the Cu film substrate. In addition, the electrical and mechanical properties of the Cu NSF are studied under various fabrication conditions. The Cu NSF exhibits high shear adhesion strength (∼234 N cm^-2) and low contact resistivity (2.2 × 10^-4 Ω cm²).