Surface protection against corrosion of Ni turbine blades by electrophoretic deposition of MnO2, TiO2 and TiO2-C nanocoating

The turbine blades of turbochargers are corroded after being cleaned with water in the presence of gasses produced during the combustion of heavy fuel. For that, manganese oxide (MnO₂), titanium dioxide (TiO₂), and titanium oxide-graphene (TiO₂-C) nanomaterials have been coated on the nickel alloy, which is the composition of turbine blades, by the electrophoretic deposition technique for protection against the corrosion process. The anticorrosion performance of nanomaterial coatings has been investigated using electrochemical methods such as open circuit potential, potentiodynamic, electrochemical impedance, and linear polarization resistance in a 1 M H₂SO₄ solution saturated with carbon dioxide. The corrosion rate of nanomaterial-coated Ni-alloy was lower than bare alloy, and potential corrosion increased from -0.486 V for uncoated Ni-alloy to -0.252 V versus saturated calomel electrode for nanomaterial coated Ni-alloy electrodes. Electrochemical measurements show that TiO₂ coated Ni-alloy corrosion has good protective qualities, with an efficiency of 99.91% at 0.146 mA cm² current density in sulfuric acid media. The findings of this study clearly show that TiO₂ has a high potential to prevent nickel alloy turbine blades from corrosion in acidic media. Furthermore, the surface morphologies have revealed that TiO₂ and MnO₂ coatings might successfully block an acid assault due to the high adhesion of the protective layer on the nickel alloy surface. The use of X-ray diffraction (XRD) enhanced the various measures used to determine and study the composition of the alloy surface's protective coating.

Biological Metabolism Synthesis of Metal Oxides Nanorods from Bacteria as a Biofactory toward High-Performance Lithium-Ion Battery Anodes

Increasing awareness toward environmental remediation and renewable energy has led to a vigorous demand for exploring a win-win strategy to realize the eco-efficient conversion of pollutants ("trash") into energy-storage nanomaterials ("treasure"). Inspired by the biological metabolism of bacteria, Acidithiobacillus ferrooxidans (A. ferrooxidans) is successfully exploited as a promising eco-friendly sustainable biofactory for the controllable fabrication of α-Fe₂ O₃ nanorods via the oxidation of soluble ferrous irons to insoluble ferric substances (Jarosite, KFe₃ (SO₄ )₂ (OH)₆ ) and a facile subsequent heat treatment. It is demonstrated that the stable solid electrolyte interphase layers and marvelous cracks in situ formed in biometabolic α-Fe₂ O₃ nanorods play important roles that not only significantly enhance the structure stability but also facilitate electron and ion transfer. Consequently, these biometabolic α-Fe₂ O₃ nanorods deliver a superior stable capacity of 673.9 mAh g^-1 at 100 mA g^-1 over 200 cycles and a remarkable multi-rate capability that observably prevails over the commercial counterpart. It is highly expected that such biological synthesis strategies can shed new light on an emerging field of research interconnecting biotechnology, energy technology, environmental technology, and nanotechnology.

One-step thermolysis synthesis of two-dimensional ultrafine Fe3O4 particles/carbon nanonetworks for high-performance lithium-ion batteries

To tackle the issue of inferior cycle stability and rate capability for Fe3O4 anode materials in lithium ion batteries, ultrafine Fe3O4 nanocrystals uniformly encapsulated in two-dimensional (2D) carbon nanonetworks have been fabricated through thermolysis of a simple, low-cost iron(iii) acetylacetonate without any extra processes. Moreover, compared to the reported Fe3O4/carbon composites, the particle size of Fe3O4 is controllable and held down to ∼3 nm. Benefitting from the synergistic effects of the excellent electroconductive carbon nanonetworks and uniform distribution of ultrafine Fe3O4 particles, the prepared 2D Fe3O4/carbon nanonetwork anode exhibits high reversible capacity, excellent rate capability and superior cyclability. A high capacity of 1534 mA h g(-1) is achieved at a 1 C rate and is maintained without decay up to 500 cycles (1 C = 1 A g(-1)). Even at the high current density of 5 C and 10 C, the 2D Fe3O4/carbon nanonetworks maintain a reversible capacity of 845 and 647 mA h g(-1) after 500 discharge/charge cycles, respectively. In comparison with other reported Fe3O4-based anodes, the 2D Fe3O4/carbon nanonetwork electrode is one of the most attractive of those in energy storage applications.

Facile synthesis of an Fe3O4/FeO/Fe/C composite as a high-performance anode for lithium-ion batteries

An Fe₃O₄/FeO/Fe/C nanocomposite is prepared via a facile and scalable in situ-reduction solid synthesis route and is used as a high-performance LIB anode.

Template free construction of a hollow Fe3O4 architecture embedded in an N-doped graphene matrix for lithium storage

The rational design and fabrication of electrode materials is a significant, yet highly challenging task.

Polyhedral Fe3O4 nanoparticles for lithium ion storage

Fe₃O₄ nanoparticles composed of 14-facet and 26-facet polyhedrons exhibited a high initial discharge capacity of 1067 mA h g⁻¹.

Fe3O4@porous carbon hybrid as the anode material for a lithium-ion battery: performance optimization by composition and microstructure tailoring

Fe₃O₄@C has been synthesized using the syn-carbonization strategy and the electrochemical performances have been optimized by tailoring the composition and microstructure.

Stabilising a Mn3O4 nanosheet on graphene via forming a 2D–2D nanostructure for improvement of lithium storage

The 2D–2D nanostructured composite of Mn₃O₄ nanosheet stabilising on graphene sheet presents the enhanced electrochemical performances.

Carbon coated manganese monoxide octahedron negative-electrode for lithium-ion batteries with enhanced performance

Carbon coated MnO octahedra with narrow size distribution and good dispersity have been fabricated and applied as lithium ion battery anode materials.

Surfactant-assisted synthesis of Fe2O3 nanoparticles and F-doped carbon modification toward an improved Fe3O4@CFx/LiNi0.5Mn1.5O4 battery

A simple surfactant-assisted reflux method was used in this study for the synthesis of cocklebur-shaped Fe2O3 nanoparticles (NPs). With this strategy, a series of nanostructured Fe2O3 NPs with a size distribution ranging from 20 to 120 nm and a tunable surface area were readily controlled by varying reflux temperature and the type of surfactant. Surfactants such as cetyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (F127) and sodium dodecyl benzenesulfonate (SDBS) were used to achieve large-scale synthesis of uniform Fe2O3 NPs with a relatively low cost. A new composite of Fe3O4@CFx was prepared by coating the primary Fe2O3 NPs with a layer of F-doped carbon (CFx) with a one-step carbonization process. The Fe3O4@CFx composite was utilized as the anode in a lithium ion battery and exhibited a high reversible capacity of 900 mAh g(-1) at a current density of 100 mA g(-1) over 100 cycles with 95% capacity retention. In addition, a new Fe3O4@CFx/LiNi(0.5)Mn(1.5)O4 battery with a high energy density of 371 Wh kg(-1) (vs cathode) was successfully assembled, and more than 300 cycles were easily completed with 66.8% capacity retention at 100 mA g(-1). Even cycled at the high temperature of 45 °C, this full cell also exhibited a relatively high capacity of 91.6 mAh g(-1) (vs cathode) at 100 mA g(-1) and retained 54.6% of its reversible capacity over 50 cycles. Introducing CFx chemicals to modify metal oxide anodes and/or any other cathode is of great interest for advanced energy storage and conversion devices.

Well-dispersed ultrafine Mn3O4 nanocrystals on reduced graphene oxide with high electrochemical Li-storage performance

The Mn₃O₄–reduced graphene oxide composite synthesized by a microexplosion mechanism shows high electrochemical Li-storage performance.

Synthesis of Cu@Fe3O4 nanowire arrays electrode for Li-ion batteries

Three-dimensional (3D) electrodes of Cu@Fe₃O₄ nanowire arrays for Li-ion batteries are prepared by an electrochemical route.