Effect of Li⁺, Mg²⁺, and Al³⁺ Substitution on the Performance of Nickel Ferrite-Based Hydroelectric Cells

Abstract

Defect engineering in nickel ferrite has been performed to enhance the power output of the hydroelectric cell (HEC). Oxygen vacancies can be tuned in the ferrite using different valence element substitutions to enhance water dissociation by hydroelectric cells. In this work, Li+, Mg2+, and Al3+ substituted at the nickel site in nickel ferrite (NiFe2O4) are synthesized and studied for hydroelectric cell devices. Introducing these Li+, Mg2+, and Al3+ substituents (of a different atomic radius and valence charge state) in nickel ferrite leads to the generation of oxygen vacancy differently, which is discussed thoroughly in this work. In comparison to Mg and Al, lithium substitution lowers the overall cationic charge in nickel ferrite, leading to formation of a high number of oxygen vacancies for overall ionic charge compensation. Lithium-substituted nickel ferrite (NLFO) has a high number of defects (oxygen vacancies, etc.) compared to Mg-substituted (NMFO) and Al-substituted (NAFO) nickel ferrite, confirmed by X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The highest peak area of oxygen vacancies in the O 1s core-level spectra has been obtained for the case of NLFO among NLFO, NMFO, and NAFO. These vacancy sites provide a large number of adsorption sites for water molecule adsorption and dissociation. A high lattice strain (9.83 × 10–4) is induced in NLFO calculated by the Williamson–Hall plot. The porous nature of all samples has been confirmed from FESEM and BET analysis. The charge transfer processes in dry and wet HECs have been analyzed by fitting an equivalent RC circuit in the Nyquist spectra. The lithium-substituted nickel ferrite HEC with rich oxygen vacancies generates a high short-circuit current of ∼58.7 mA, which is ∼2 times higher than that of NMFO HEC and ∼3 times higher than that of NAFO HEC.

A Sustainable and Regenerative Process for the Treatment of Textile Effluents Using Nonphotocatalytic Water Splitting by Nanoporous Oxygen-Deficient Ferrite

“…The O 1s peak was deconvoluted into four peaks centered at 529.47, 531.79, 533.18, and 534.7 eV (Figure d). The peak at 529.47 eV was assigned to the lattice oxygen, while the peak at a binding energy of 531.92 was attributed to the chemisorbed layer of hydroxyl groups on the surface due to the chemi-dissociation of water near vacancy centers. , The peak centered at 533.18 eV was assigned to the water layer strongly bound to the chemisorbed hydroxyl monolayer. The peak centered at a high binding energy of ∼534.7 eV was attributed to the strongly bound physisorbed water layers .…”

Optimization of the structural, optical, and magnetic properties of sol-gel derived La3+ substituted nanostructured barium hexaferrites

“…These findings suggest that La 3+ ions have a high surface-to-volume ratio and significant reactivity [42][43][44]. The created material's porous architectures may make it easier to use it for hydroelectric cell applications and drug release, both of which have recently undergone ground-breaking research [45][46][47][48].…”

Effect of Dy3+ and Tb3+ Rare-Earth Cation Co-Substitution on the Structure, Magnetic, and Magnetostrictive Properties of Ni-Co-Ferrites

“…1−5 A reversible energy exchange between the mechanical form and the magnetic form frequently occurs during magnetostriction. 6,7 Due to its ability to precisely transform a certain quantity of energy from one form to other, the magnetostrictive materials can actually be employed in a wide range of industrial applications, particularly in sensors and actuators. 8,9 As a result, functional materials that exhibit magnetostriction are currently the subject of intense attention for research and development activities.…”

“…The design and development of the state-of-the-art sensors for automotive and energy technologies are highly relevant to the phenomenon of magnetostriction, which occurs when a magnetic field is applied and causes changes in the physical dimensions of magnetic materials. − A reversible energy exchange between the mechanical form and the magnetic form frequently occurs during magnetostriction. , Due to its ability to precisely transform a certain quantity of energy from one form to other, the magnetostrictive materials can actually be employed in a wide range of industrial applications, particularly in sensors and actuators. , As a result, functional materials that exhibit magnetostriction are currently the subject of intense attention for research and development activities. From this viewpoint, and due to their low cost of synthesis and processing, chemical and mechanical stability, low eddy current, suitability for high-frequency devices, etc., ferrite-based materials are particularly appealing …”

“…Nickel ferrite (NiFe 2 O 4 ; NFO), which is one of the spinel ferrite families, finds interesting applications in numerous technologies, including the sensors for automotive and energy technologies. , NFO continues to draw the attention of the scientific and research community in view of its excellent properties, such as high electrical resistivity (greater than 10 9 Ω cm), low eddy current loss, notable physical and chemical stability, high Curie temperature ( T c = 585 °C), moderate saturation magnetization and coercivity, and good strain sensitivity at a lower magnetic field ( H ≤ 1000 Oe). ,, The structural, chemical, electronic, and magnetic properties make NFO and NFO-based materials quite attractive in many applications, such as in recording media, three-dimensional transformers, high-frequency devices, strain sensors, magnetic field sensors, magnetoelectrical sensors, and also biological applications. However, as to magnetostrictive characteristics, NFO exhibits a soft magnetic and low anisotropy with a magnetostriction measured in the range of −25 to −40 ppm at relatively low magnetic fields.…”