Nanomaterials

ISSN

2079-4991

Издатель

Multidisciplinary Digital Publishing Institute

Ключевые слова

Nanoparticles: synthe...

Gold and Silver Nanop...

Graphene research and...

Advanced Photocatalys...

Nanoparticle-Based Dr...

Публикации в журнале

Показано: 1 - 3 из 3

Некоторые метрики заблокированы вашими
настройками согласия
FeMnO3: Synthesis, Morphology, Dielectric Properties, and Electrochemical Behavior Toward HER by LSV
(Multidisciplinary Digital Publishing Institute, 2026-02-27)
Mukhametkali Musagalievich Mataev
;
Zamira Sarsenbaeva
;
Marzhan Nurbekova
;
Ramachandran Krishnamoorthy
;
Bahadır Keskin
This paper presents a comprehensive investigation into the synthesis, morphological characteristics, electrical conductivity, dielectric behavior, and electrocatalytic activity of perovskite-structured iron manganite (FeMnO3), with a specific focus on its performance in the hydrogen evolution reaction (HER). FeMnO3(FMO) nanoparticles (NPs) were synthesized using a sol–gel-type Pechini method and characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (FESEM-EDS). XRD analysis confirmed the formation of a crystalline structure with cubic symmetry assigned to the Ia-3 space group, with an average crystallite size of 52.47 nm. FESEM images revealed a relatively uniform morphology with an average particle diameter of 55.84 nm. The redox and oxidation states of Fe and Mn can be studied by temperature-programmed oxidation (TPO-O2) in order to understand oxygen uptake and metal oxidation processes occurring within the FMO lattice. The dielectric constant, dielectric loss, electric modulus and electrical conductivity were calculated as a function of frequency and temperature using a Novocontrol Alpha-A broadband dielectric spectrometer (Novocontrol system) coupled with the LCR-800 precision meter. The dielectric data reveal that the FMO has semiconducting behavior with dominant charge- or ionic-relaxation processes. The electrocatalytic activity toward the HER was evaluated using linear sweep voltammetry (LSV), with the working electrode modified by an FMO catalyst ink. The material exhibited significant catalytic activity within the HER potential range, and an increase in the number of cycles led to stabilized current and enhanced hydrogen evolution. These results highlight the stability of FeMnO3 for hydrogen generation.
Некоторые метрики заблокированы вашими
настройками согласия
Sustainable Energy Storage Systems: The Promise of Biomass-Derived Carbon Materials for High-Performance Supercapacitors
(Multidisciplinary Digital Publishing Institute, 2026-04-26)
Aigerim R. Seitkazinova
;
Muhammad Hashami
;
Meruyert Nazhipkyzy
;
Roza G. Abdulkarimova
;
Zhanar Kudyarova
The rapid demand for sustainable and efficient energy storage solutions has prompted the pursuit of eco-friendly electrode materials. Biomass-derived carbons from food waste offer a promising pathway to meet this need by combining waste valorization, environmental benefits, and high electrochemical performance. This review highlights that food waste biomass is an effective and inexpensive source of precursors for producing high-performance carbon materials for supercapacitors. Food waste, which includes fruit peels and vegetable residues, cereal husks, and oilseed residues, is a good source of lignocellulosic components, heteroatoms, and structural features that determine the electrochemical characteristics of the derived carbons. These wastes produce hierarchically porous carbons with high surface areas (>1500 m2 g−1) on pyrolysis and activation that provide superior ion transport, wettability and pseudocapacitive behaviour. Their electrochemical performance includes capacitances up to 520 F g−1 and energy densities of 35–70 Wh kg−1 in optimized systems, particularly under extended voltage windows or in hybrid supercapacitor configurations, and high cycling stability is equal to or even better than traditional carbons such as activated carbon and graphene. Additionally, biomass valorization contributes to a high level of greenhouse gas capture, decreases landfill, and correlates with the idea of a circular economy. The commercialization potential of biomass-based supercapacitors is supported by recent developments in AI-based optimization, combined with scalable synthesis methods, which would support ecologically, economically, and technologically sustainable energy storage on a large scale.
Цитирования (OpenAlex) 3
Некоторые метрики заблокированы вашими
настройками согласия
From Coprecipitation to Nanostructure: Formation, Morphology, and Reactive-Site Accessibility in Fe-Containing Binary Layered Double Hydroxides
(Multidisciplinary Digital Publishing Institute, 2026-09-24)
Alua Alikeyeva
;
Nurbolat Kudaibergenov
;
Kairzhan Shalmagambetov
;
A.I. Azimbay
Binary Fe-containing LDHs and structurally related layered hydroxides are being widely investigated as adsorbents, catalysts, and redox-active nanomaterials. Yet, links among coprecipitation, phase formation, nanostructure, and reactive-site accessibility remain inconsistently interpreted. This critical review evaluates studies published mainly from 2015 to July 2026 on CoFe, NiFe, MgFe, ZnFe, MnFe, CuFe, and CaFe layered hydroxides and Fe(II)/Fe(III) green rust. Coprecipitation is not a single standardized route: local supersaturation, reagent delivery, mixing, complexation, atmosphere, interlayer chemistry, and aging can alter metal incorporation and phase development, while Fe-rich transient precursors may participate under system-specific conditions. The commonly cited Fe(III) fraction of x = 0.20–0.33 is an empirical guideline rather than a universal stability window, and conventional M(II)-Fe(III) LDHs, CaFe hydrocalumite-/AFm-related phases, and green rust require distinct crystal-chemical interpretations. Nominal composition and LDH-like diffraction cannot establish homogeneous cation incorporation or phase purity. In contrast, diffraction broadening, BET area, nanosheet dimensions, and XPS fitting do not provide stand-alone evidence of defects or accessible reactive sites. Progress toward predictive synthesis requires standardized reporting, system-specific synthesis–composition–phase maps, time-resolved studies, quantitative structure–accessibility relationships, and recognition of as-synthesized, working, recovered, and regenerated materials as potentially distinct structural states, supported by uncertainty analysis, negative outcomes, and validation across laboratories.

Nanomaterials

Фильтры

Настройки

Сортировать по

результатов на странице