Valorization of lignin in polymer and composite systems for advanced engineering applications – A review

Microwave-assisted synthesis of Mn3O4-Fe2O3/Fe3O4@rGO ternary hybrids and electrochemical performance for supercapacitor electrode

A review on carbon and non-precious metal based cathode catalysts in microbial fuel cells

In recent years, the remediation of hazardous organic contaminants using semiconductor metal oxide photocatalyst has taught extensive attention Next to TiO2, ZnO has been well-known as a significant photocatalyst material Due to the formation of different defects, even though photocatalysis using bare ZnO is useful in pollutant remediation, several drawbacks make it less effective In this review, to reduce these drawbacks, forming a heterojunction between different bandgap metal oxides has been assessed Among different metal oxides that form a suitable heterojunction with ZnO, depending on the ideas of regeneration, surface area, and stability; this review focuses on iron oxide and manganese oxide materials Different analytical techniques that confirm the improvement of bare ZnO towards electron-hole recombination, surface area, photo corrosion, and regeneration were also discussed During the adsorption-photocatalysis experiment, to understand the detailed surface reaction information, testing at least some selected adsorption isotherm and adsorption kinetics models is critical Furthermore, to know the close association between the adsorption process in the dark and during light irradiation, comparing their adsorption isotherm constant is also necessary

Enhancing the photocatalytic efficiency of ZnO: Defects, heterojunction, and optimization

MXenes are the class of two-dimensional transition metal carbides and nitrides that exhibit unique properties and are used in a multitude of applications such as biosensors, water purification, electromagnetic interference shielding, electrocatalysis, supercapacitors, and so forth. Carbide-based MXenes are being widely explored, whereas investigations on nitride-based ones are seldom. Among the nitride-based MXenes obtained from their MAX phases, only Ti4N3 and Ti2N are reported so far. Herein, we report a novel synthesis of V2NT x (T x is the surface termination) obtained by the selective removal of "Al" from V2AlN by immersing powders of V2AlN in the LiF-HCl mixture (salt-acid etching) followed by sonication to obtain V2NT x (T x = -F, -O) MXene which is then delaminated using the dimethyl sulfoxide solvent. The V2NT x MXene is characterized by X-ray diffraction studies, field emission scanning electron microscope imaging, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscope imaging. Supercapacitor electrodes are prepared using V2NT x MXenes and their electrochemical performances are examined by cyclic voltammetry, galvanostatic charge/discharge measurement, and electrochemical impedance spectroscopy. The V2NT x MXene electrode exhibits a specific capacitance of 112.8 F/g at a current density of 1.85 mA/cm2 with an energy and power density of 15.66 W h/kg and 3748.4 W/kg, respectively, in 3.5 M KOH aqueous electrolyte. The electrode exhibits an excellent capacitance retention of 96% even after 10,000 charge/discharge cycles. An asymmetric supercapacitor fabricated with V2NT x as a negative electrode and Mn3O4 nanowalls as a positive electrode helps obtain a cell voltage of 1.8 V in aqueous KOH electrolyte.

New Method for the Synthesis of 2D Vanadium Nitride (MXene) and Its Application as a Supercapacitor Electrode.

Recent developments in manganese oxide based nanomaterials with oxygen reduction reaction functionalities for energy conversion and storage applications: A review

Review on manganese oxide based biocatalyst in microbial fuel cell: Nanocomposite approach

Physicochemical parameter influences and their optimization on the biosynthesis of MnO2 nanoparticles using Vernonia amygdalina leaf extract

Organic solvent-free impregnation method was used to synthesize titanium-iron oxides (TIOs) nanomaterial. The physical properties of synthesized TIOs materials were characterized by XRD, SEM–EDX, BET, UV–Vis, and FTIR analytical techniques. The appearance of iron oxide (IO) on SEM image, XRD, and EDX spectra, the redshift on UV–Vis spectra of TIO compared to titanium oxide (TO), and intensity reduction in FTIR spectra proves the good impregnation of IO in TO lattice. The Langmuir and Dubinin–Radushkevich adsorption isotherm test in the dark show the domination of physical adsorption. Furthermore, the Flory–Huggins isotherm model that has $$\Delta G$$ = −11.40 kJ/mol and Fowler–Guggenheim model that has $$w$$ = −106.5 kJ/mol confirm the spontaneity of the reaction and the presence of adsorbate–adsorbate repulsive interaction, respectively. The passing of the linear Weber–Morris intraparticle adsorption–diffusion plot through the origin and well-fitting of its coefficient of determination (R2) value relative to pseudo-first-order indicates the domination of adsorption–diffusion mechanism. On the methyl orange degradation experiment, as the percentage of IO increases from 4 to 12, its degradation efficiency decreases, i.e., TIO with 4% calcined at 500 °C (TIO-4) has higher degradation efficiency with k values of 0.03025.

Synthesis and Characterization of Ti–Fe Oxide Nanomaterials: Adsorption–Degradation of Methyl Orange Dye

Electropolymerization and redox behavior of lignin composites were characterized by cyclic voltammetry (CV), electrochemical quartz crystal microbalance (EQCM), and Fourier transform infrared spectroscopy (FTIR). Oxidation of lignin (LG) composites mixed with different polymers such as; Poly (o-phenylenediamine) (POPDA), Pyrrole (Py), 4-amino-3-hydroxynaphthalene-sulfonic acid (AHNSA) on working glassy carbon electrode (GCE) were performed by cyclic voltammetry in a three-electrode electrochemical cell. EQCM was used during polymerization technique and detecting the continuous mass increase with the number of potential cycles. Transmission FTIR spectra of the electropolymerized film of pyrrole and lignin composite polymer after deposition were recorded. These results gave evidence of lignin composite formation due to the fact that new and broad bands in the region of 3411"3460 cm ”1 were observed.

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Yilkal Dessie

Papers

Recent developments in manganese oxide based nanomaterials with oxygen reduction reaction functionalities for energy conversion and storage applications: A review

Review on manganese oxide based biocatalyst in microbial fuel cell: Nanocomposite approach

Physicochemical parameter influences and their optimization on the biosynthesis of MnO2 nanoparticles using Vernonia amygdalina leaf extract

Synthesis and Characterization of Ti–Fe Oxide Nanomaterials: Adsorption–Degradation of Methyl Orange Dye

Electrochemical Study of Conducting Polymer/Lignin Composites