Hydrothermal Synthesis of Spinel-Perovskite Li–Mn–Fe–Si Nanocomposites for Electrochemical Hydrogen Storage

Abstract

Owing to the extensive requirement for renewable energy sources such as hydrogen, great efforts are being devoted to optimizing the active ingredients for advanced hydrogen storage. In this regard, an ideal spinel-perovskite nanocomposite based on Li−Mn−Fe−Si materials was successfully fabricated via a one-pot hydrothermal route to store hydrogen electrochemically. To optimize both the phase composition and morphological features of nanostructures, the reaction was engineered under different conditions. Li−Mn−Fe−Si spinel-perovskite diphase structures were created with diverse shapes of polyhedral-shaped bulk particles, nanoparticles, nanoplates, and hierarchical structures. The alteration of multiple factors such as hydrothermal reaction time, temperature, polymeric surfactant type, and calcination temperature was surveyed to achieve the optimized size and morphology of the nanoproducts to be obtained. The morphological changes, structural regulations, porosity, and magnetic properties of the nanosized products were studied via field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray powder diffraction (XRD), Raman spectroscopy, Brunauer−Emmett−Teller (BET), and vibrating sample magnetometer (VSM) analyses. In addition, the electrochemistry features of the Li 0.66 Mn 1.85 Fe 0.43 O 4 /Fe 2.57 Si 0.43 O 4 /FeSiO 3 (LMFO/FSO) nanocomposites were introduced on the basis of discharge capacity, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry(CV) methods in an alkaline electrolyte. The discharge capacity of the LMFO/FSO nanostructures with a nanoplate-like morphology as an optimal sample was calculated to be 910 mAh/g after 15 cycles at a constant current of 1 mA. The electrochemistry results confirm that the hydrogen storage capability of nanoplate composites is higher than those of other morphologies due to their superior surface area and faster electron transfer. Besides, this proposed strategy could simultaneously manipulate the architectural and compositional complexities to generate a superior electrochemical behavior in energy storage devices.

Effects of Capping Agents on Shape, Stability, and Oxygen Evolution Reaction Activity of Copper Nanoparticles

“…Due to oxidized Cu species being harder to reduce than nonoxidized species, the levels of Cu in the produced nanocatalysts were lower than the feeding ratio. 3 The pure uncapped Cu NPs were likewise made using the same procedure as the capped Cu nanocatalysts under the present system. 6 The produced catalysts' line scan elemental profiles and mapping for oxygen (green) and Cu (yellow) contents show that the catalysts have a high concentration of Cu (Fig.…”

“…OER is consequently believed to be the bottleneck in water electrolyzers. [1][2][3] Additionally, metal-air batteries, regenerated fuel cells, and carbon dioxide electrolyzers utilize the oxygen evolution process in anodes. 4 Therefore, for these electrochemical energy devices, the development of efficient OER electro-catalysts is essential.…”

In Situ Grown (Fe,Mn,Ga)3O4–x Spinel/(Mn,Fe)2O3–y Bixbyite Dual-Phase Electrocatalyst for Preeminent Nitrogen Reduction to Ammonia: A Step toward the NH3 Economy

“…25−29 Dual-phase spinel/perovskite systems from bimetal La−Co and tetrametal Li−Mn− Fe−Si were reported. 30,31 Their nanocomposites contained nonstoichiometric compounds of Li 0.66 Mn 1.85 Fe 0.43 O 4 and Fe 2.57 Si 0.43 O 4 . The nonstoichiometry in multimetal oxide compounds creates complex defective structures.…”

“…The in situ grown dual-phase engineering of precious metal-free transition metal-based compounds to form the nonstoichiometric and three-dimensionl (3D) architecture composites with multiple charge valences, oxygen vacancy, and lattice distortion in each phase is less evaluated but promising for the catalyst development. − Dual-phase spinel/perovskite systems from bimetal La–Co and tetrametal Li–Mn–Fe–Si were reported. , Their nanocomposites contained nonstoichiometric compounds of Li 0.66 Mn 1.85 Fe 0.43 O 4 and Fe 2.57 Si 0.43 O 4 . The nonstoichiometry in multimetal oxide compounds creates complex defective structures.…”

Preparation of CO2‐activated Porous Graphene for Enhancing the Electrochemical Hydrogen Storage Properties of Co9S8 Material

“…Among a variety of hydrogen storage techniques, the electrochemical method is very promising because of its safety, availability and accuracy [3,4] . For hydrogen storage material, different kinds of alloys including rare earth‐based, Ti‐based, Zr‐based, Mg‐based and V‐based solid solution alloys, have been extensively investigated for electrochemical hydrogen storage and alkaline secondary batteries [5–9] . Recently, Co‐based alloy becomes the hot spot and shows great development prospects due to its high theoretical capacity.…”