Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Omega ; 9(13): 15650-15662, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38585114

RESUMO

The current study attempts to establish the interrelation between microstructure and magnetic properties induced during laser melting of the FeNi alloy. This study demonstrates the optimization of laser parameters for defect-free, uniform, and chemically homogeneous FeNi alloy synthesis. Mechanically alloyed FeNi (50-50 atom %) powders obtained after 12 and 24 h milling, with average particle sizes of 15 and 7 µm, were used as starting materials. It was found that the optimum range of laser power density for synthesis of dense and defect-free solids is between 1 and 1.4 J/mm2. For laser melting under similar conditions, 12 h milled FeNi powder produces a larger grain (∼100 µm) with a preferred texture of (001), compared to 25 µm grain size in 24 h milled FeNi, with random texture. Smaller grain size is correlated with higher resistance to domain wall movement, resulting in higher coercivity and remanence in the laser-melted samples prepared from 24 h of milled powder. The presence of microtexture in laser-melted samples prepared from 12 h milled powder is related to a higher anisotropy.

2.
Small ; : e2311585, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38576110

RESUMO

The incorporation of redox-active species into the electric double layer is a powerful strategy for enhancing the energy density of supercapacitors. Polyoxometalates (POM) are a class of stable, redox-active species with multielectron activity, which is often used to tailor the properties of electrochemical interfaces. Traditional synthetic methods often result in interfaces containing a mixture of POM anions, unreactive counter ions, and neutral species. This leads to degradation in electrochemical performance due to aggregation and increased interfacial resistance. Another significant challenge is achieving the uniform and stable anchoring of POM anions on substrates to ensure the long-term stability of the electrochemical interface. These challenges are addressed by developing a mass spectrometry-based subambient deposition strategy for the selective deposition of POM anions onto engineered 3D porous carbon electrodes. Furthermore, positively charged functional groups are introduced on the electrode surface for efficient trapping of POM anions. This approach enables the deposition of purified POM anions uniformly through the pores of the 3D porous carbon electrode, resulting in unprecedented increase in the energy storage capacity of the electrodes. The study highlights the critical role of well-defined electrochemical interfaces in energy storage applications and offers a powerful method to achieve this through selective ion deposition.

3.
Small ; 20(24): e2308886, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38174607

RESUMO

Rechargeable Mg-ion Batteries (RMB) containing a Mg metal anode offer the promise of higher specific volumetric capacity, energy density, safety, and economic viability than lithium-ion battery technology, but their realization is challenging. The limited availability of suitable inorganic cathodes compatible with electrolytes relevant to Mg metal anode restricts the development of RMBs. Despite the promising capability of some oxides to reversibly intercalate Mg+2 ions at high potential, its lack of stability in chloride-containing ethereal electrolytes, relevant to Mg metal anode hinders the realization of a full practical RMB. Here the successful in situ encapsulation of monodispersed spherical V2O5 (≈200 nm) is demonstrated by a thin layer of VS2 (≈12 nm) through a facile surface reduction route. The VS2 layer protects the surface of V2O5 particles in RMB electrolyte solution (MgCl2 + MgTFSI in DME). Both V2O5 and V2O5@VS2 particles demonstrate high initial discharge capacity. However, only the V2O5@VS2 material demonstrates superior rate performance, Coulombic efficiency (100%), and stability (138 mA h g-1 discharge capacity after 100 cycles), signifying the ability of the thin VS2 layer to protect the V2O5 cathode and facilitate the Mg+2 ion intercalation/deintercalation into V2O5.

4.
Nat Nanotechnol ; 19(2): 208-218, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37798568

RESUMO

A critical current challenge in the development of all-solid-state lithium batteries (ASSLBs) is reducing the cost of fabrication without compromising the performance. Here we report a sulfide ASSLB based on a high-energy, Co-free LiNiO2 cathode with a robust outside-in structure. This promising cathode is enabled by the high-pressure O2 synthesis and subsequent atomic layer deposition of a unique ultrathin LixAlyZnzOδ protective layer comprising a LixAlyZnzOδ surface coating region and an Al and Zn near-surface doping region. This high-quality artificial interphase enhances the structural stability and interfacial dynamics of the cathode as it mitigates the contact loss and continuous side reactions at the cathode/solid electrolyte interface. As a result, our ASSLBs exhibit a high areal capacity (4.65 mAh cm-2), a high specific cathode capacity (203 mAh g-1), superior cycling stability (92% capacity retention after 200 cycles) and a good rate capability (93 mAh g-1 at 2C). This work also offers mechanistic insights into how to break through the limitation of using expensive cathodes (for example, Co-based) and coatings (for example, Nb-, Ta-, La- or Zr-based) while still achieving a high-energy ASSLB performance.

5.
ACS Omega ; 8(41): 38704-38714, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37867695

RESUMO

A nonisothermal thermogravimetric analysis (TGA) technique was applied to determine the devolatilization kinetic parameters of completely different genesis samples of four groups: coal, biomass, lignite, and petcoke. The physical and chemical characteristics were determined using the proximate and ultimate analysis and the ash composition profile using the X-ray fluorescence method. Heating rates of 10, 15, and 20 °C/min were used in the temperature range of 25-1000 °C during the slow pyrolysis under an inert gas atmosphere. A widely used and proposed first-order Coats-Redfern kinetic model was applied, which showed the highest values of activation energies (Ea) for the petcoke sample from 57.17 to 67.58 kJ/mol at three different heating rates, while the lignite sample represented the lowest Ea values between 12.84 and 16.03 kJ/mol. The thermo-kinetic behavior was explained based on the catalytic effect of the ash composition profile, morphology, and structure of the substances determined using different analytical techniques. For the TGA process, the application of scanning electron microscopy, Fourier-transform infrared spectroscopy, etc., for the physiochemical analysis of the four genetically different carbon-source materials represented the novelty of the present work.

6.
Waste Manag ; 167: 1-12, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37229850

RESUMO

This work aims to perform the applied mineralogical characterization of coal gasification ash (CGA) generated from a commercial fixed bed downdraft gasification plant in eastern India. Analytical and characterization techniques such as stereomicroscopy, optical microscopy, field emission scanning electron microscopy (FESEM) with energy dispersive spectroscopy (EDS) attached, X-ray fluorescence (XRF), energy dispersive x-ray spectrometer associated scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were applied for analyzing the coal and the corresponding gasification ash sample. These analytical techniques illustrate that SiO2 and Al2O3 are the major gasification ash phases, accounting for almost 85% of the entire CGA composition. The dominant mineral phases, such as quartz, mullite, and other aluminosilicates, provide an opportunity for utilization in construction and refractory material manufacturing. Moreover, confirming the presence of rare and valuable earth elements (RVEEs) in the CGA sample with SEM-EDX analysis unearths a new application window in meeting the requirement of the RVEEs starved nation like India, where very few commercial-scale coal gasification units are operational.


Assuntos
Cinza de Carvão , Dióxido de Silício , Cinza de Carvão/química , Difração de Raios X , Carvão Mineral/análise , Minerais/análise
7.
ACS Omega ; 8(15): 13690-13701, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37091413

RESUMO

L10-ordered FeNi, tetrataenite, found naturally in meteorites is a predilection for next-generation rare-earth free permanent magnetic materials. However, the synthesis of this phase remains unattainable in an industrially relevant time frame due to the sluggish diffusion of Fe and Ni near the order-disorder temperature (593 K) of L10 FeNi. The present work describes the synthesis of ordered L10 FeNi from elemental Fe and Ni powders by mechanical alloying up to 12 h and subsequent heat treatment at 623 K for 1000 h without a magnetic field and for 4 h in the presence of 1.5 T magnetic field. Also, to address the ambiguity of L10 phase identification caused by the low difference in the X-ray scattering factor of Fe and Ni, synchrotron-based X-ray diffraction is employed, which reveals that 6 h milling is sufficient to induce L10 FeNi formation. Further milling for 12 h is done to achieve a chemically homogeneous powder. The phase fraction of L10-ordered FeNi is quantified to ∼9 wt % for 12 h milled FeNi, which increases to ∼15 wt % after heat treatment. Heat treatment of the milled powder in a magnetic field increases the long-range order parameter (S) from 0.18 to 0.30. Further, the study of magnetic properties reveals a decrease in magnetic saturation and a slight increase in coercivity with the increase in milling duration. At the same time, heat treatment in the magnetic field shows a considerable increase in coercivity.

8.
Chem Asian J ; 17(24): e202200948, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36214361

RESUMO

There is ever-growing interest to develop intrinsic white light emitting single-phase phosphors that have high CRI, devoid of bluish tinge, ease of synthesis and are scalable. Herein, manipulating vacuum pressure to instigate white light emission in Cu2+ -doped-ZnS phosphors is reported. The detailed X-ray diffraction and electron microscopy confirm the cubic phase of Cu2+ -doped-ZnS phosphor having agglomerated particles (∼130-150 nm). The incorporation of Cu2+ in the ZnS lattice is substantiated by the anti-Stokes shift of Raman peaks and shifting of XRD peaks to higher 2θ values. Upon increasing Cu2+ doping concentration, the resulted decrease in the FWHM of XRD peaks implies shrinkage of the ZnS lattice. Interestingly, by tailoring the excitation wavelength, the stoichiometry of dopant ion, and defect states by varying the vacuum pressure, the optimized ZSC-3 (3% Cu2+ -doped-ZnS) displays the origin of clear blue, green and red emission bands, consequently giving rise to white light emission (CIE values: 0.345:0398). The PLQY and average lifetime calculated for ZSC-3 are 5.98% and 1.5 ms, respectively. Such intense white light emission prompted to fabricate a prototype using a 310 nm UV LED. It exhibits high CRI (97) and warm CCT (4538 K), meeting highly desired values for a white light-emitting phosphor for different lighting and electroluminescence applications.

9.
Inorg Chem ; 61(30): 11550-11555, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35856872

RESUMO

The study describes the synthesis and structural attributes of two new cadmium phosphites, [Cd{OP(O)(OH)H}2(4,4'-bipy)] (1) and [H2pip][Cd(HPO3)2(H2O)]·H2O (2). The structure of 1 adopts a two-dimensional motif featuring alternate [Cd-µ2-O]2 and [Cd-O-P-O]2-cyclic rings, while the inorganic chains are held together by 4,4'-bipyridine. The presence of strong hydrogen bonding interactions between the appended H2PO3 groups (O---O = 2.55 Å) provides a facile proton conduction pathway and results in a proton conductivity of 3.2 × 10-3 S cm-1 at 75 °C under 77% relative humidity (RH). Compound 2 comprises an anionic framework formed by vertex-shared [Cd-O-P-O]2-cyclic rings, while the [H2pip] cations between the adjacent chains assist a well-directed O-H---O hydrogen-bonded network between coordinated water, lattice water, and phospite groups. The bulk proton conductivity value under conditions as in 1 reaches 4.3 × 10-1 S cm-1. For both 1 and 2, the proton conductivity remains practically unchanged under ambient temperatures (25-35 °C), suggesting their potential in low-temperature fuel cells.

10.
RSC Adv ; 12(3): 1287-1309, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35425201

RESUMO

The economic viability of CO2 reactors is contingent on the selectivity of the CO2 reduction reaction and the rate of product formation. For this, the rational design of electrolyzers also has a substantial impact on the figures of merit (current density, faradaic efficiency, cell durability). Thus, herein we portray a short review on the shortcomings, challenges and the recent developments on different reactor configurations, components and membrane structures for the efficient electrochemical CO2 reduction (CO2R) into HCOO-/HCOOH. Despite their low CO2 solubility and poor mass transport, H-type electrolyzers are commercialized due to their screening of a vast number of catalysts. In contrast, membrane-based gas and liquid phase flow reactors break the barriers faced by H-types through the incorporation of gas diffusion electrodes (GDEs) and the membrane electrode assembly (MEA). As the GDE forms the gas-liquid-solid interface, it allows the electrolyzers to generate current densities at the industrial level (200 mA cm-2). Intriguingly, a continuous liquid fed intermittent flow electrolyzer can control the electrolyte flow at a desired frequency and allow sufficient time for CO2 gas molecules to effectively reduce into HCOOH. Therefore, a high and stable faradaic efficiency (95%) is achieved in 4 h for HCOOH (576.98 mg) using the boron-doped diamond catalyst. Very recently, a novel strategy to enhance the CO2R to HCOO-/HCOOH has been adopted via the recirculation of by-products to the liquid phase MEA flow reactors, which substantially improves HCOO- selectivity, lowers material costs, and promotes CO2 mass transfer. In the end, the zero-gap electrolyzer has newly emerged and affords reduced ohmic losses, leading to a straight-forward implementation of industrial systems for CO2R to value-added products in the future. Besides, the efficiency of HCOO-/HCOOH production is also explored against proton exchange, anion exchange and bipolar membranes, and the pH of the electrolyte plays a dominant role in deciding the stability and characteristics of the membranes. It is also depicted that the product selectivity depends on different electrolyzer configurations. Recently, bimetallic alloys (Bi-Sn, Bi-In) and 2D layered composites (SnO2/rGO/CNT) have proven to be potential electrocatalysts (faradaic efficiency > 95%, highly selective and durable) assigned to the abundant active sites for CO2R. Based on the recent findings and future research directions, we draw reader's attention to construct economic, scalable and energy-efficient CO2R electrolyzers to realize the techno-economic predictions.

11.
ACS Omega ; 7(7): 5605-5614, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35224322

RESUMO

With the escalating demand for sustainable energy sources, the sodium-ion batteries (SIBs) appear as a pragmatic option to develop large energy storage grid applications in contrast to existing lithium-ion batteries (LIBs) owing to the availability of cheap sodium precursors. Nevertheless, the commercialization of SIBs has not been carried out so far due to the inefficacies of present electrode materials, particularly cathodes. Thus, from a future application perspective, this short review highlights the intrinsic challenges and corresponding strategies for the extensively researched layered transition metal oxides, polyanionic compounds, and Prussian blue analogues. In addition, the commercial feasibility of existing materials considering relevant parameters is also discussed. The insights provided in the current review may serve as an aid in designing efficient cathode materials for state-of-the-art SIBs.

12.
Talanta ; 236: 122819, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635210

RESUMO

Surface-enhanced Raman scattering (SERS) based on plasmonic metal nanoparticles and semiconductors has been used as performance-enhancing structures for sensing trace chemicals. We have selected a case of oxide functional oxide organic nanostructure between ZnFe2O4 and ZnO, denoted as ZZF. By decorating such nanostructure with AuNPs, to identify R6G in varying concentrations (10-6 M - 10-12 M), an enhancement factor of 1.6 × 108 was observed. The material was used for the identification of melamine in the concentration range of 0.39 µM-7.92 µM. This high-performance nanocomposite provides improved melamine sensitivity towards SERS and the limit of detection as low as 0.39 µM. The Au-ZZF SERS substrate can yield a SERS enhancement factor of 1.37 × 107. The experimental performance demonstrates that excellent SERS enhancement is due to electrons movement within ZZF and Au nanoparticles. Owing to its easy and effective synthesis methodology, this sensitive and specific SERS substrate is a promising technique to detect trace chemicals. We further study the best energetically favorable orientation of melamine molecules over the substrate leading to the SERS activity using density functional theoretical study.


Assuntos
Nanopartículas Metálicas , Nanocompostos , Óxido de Zinco , Ouro , Humanos , Prata , Triazinas
13.
Nanotechnology ; 33(5)2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34654005

RESUMO

A low cost, non-toxic and highly selective catalyst based on a Cu-lignin molecular complex is developed for CO2electroreduction to ethanol. Ni foam (NF), Cu-Ni foam (Cu-NF) and Cu-lignin-Ni foam (Cu-lignin-NF) were prepared by a facile and reproducible electrochemical deposition method. The electrochemical CO2reduction activity of Cu-lignin-NF was found to be higher than Cu-NF. A maximum faradaic efficiency of 23.2% with current density of 22.5 mA cm-2was obtained for Cu-lignin-NF at -0.80 V (versus RHE) in 0.1 M Na2SO4towards ethanol production. The enhancement of catalytic performance is attributed to the growth of the number of active sites and the change of oxidation states of Cu and NF due to the presence of lignin.

14.
Inorg Chem ; 60(9): 6569-6575, 2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33861061

RESUMO

Three new zinc phosphites, [HIm]2[Zn3(HPO3)4] (1), [Zn2(HPO3)2Im2] (2), and [Zn(HPO3)Im] (3) (Im = imidazole), have been synthesized from the hydro/solvothermal reaction of zinc acetate, dimethyl phosphite, and imidazole by varying the temperature and solvent of the reaction medium. The structure of 1 is built from vertex-sharing of four HPO3-capped Zn3P3 units and adopts an open framework with 12-ring channels stabilized by HIm cations via N-H···O hydrogen bonds. For 2, the inorganic skeleton is comprised of alternating ZnO4 and HPO3 tetrahedra, while the coordinatively associated ZnN2O2 fragments occupy the 12-ring hexagonal channels. Compound 3 adopts a ladder-type one-dimensional structure and exhibits N-H···O hydrogen-bonding interactions to afford a supramolecular assembly. A plausible rationale on the genesis of 1-3 has been put forth by reacting the preformed inorganic zinc phosphites Zn{OP(O)(OMe)H}2 or [Zn2(HPO3)2(H2O)4]·H2O with imidazole as the structure-directing ligand. Alternating-current impedance measurements reveal that 1 and 3 exhibit proton conductivities on the order of 10-3-10-4 S cm-1 between 25 and 100 °C under 35 and 77% relative humidity in repeated impedance cycles (Ea = 0.22-0.35 eV). On the contrary, the conduction property is completely impaired in 2 under similar conditions.

15.
Langmuir ; 37(11): 3299-3308, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33711234

RESUMO

Converting a nonwetting surface to a highly wetting one, aided by ultraviolet radiation, is well explored. Here, in this work, we show just the reverse behavior of a copper-copper oxide nanocomposite surface where ultraviolet radiation turned the superhydrophilic surface to a superhydrophobic one. This observation is explained both experimentally and theoretically using first-principles density functional theory-based calculations considering the metal-oxygen (Cu-O) bond breaking and related change in surface chemistry. This observation has further been corroborated with electron irradiation on the same nanocomposite material. To the best of our knowledge, for the first time, we show that the radiation-induced breaking of the copper-oxygen bond makes the nanostructure surface energetically unfavorable for water adsorption.

16.
ACS Omega ; 6(1): 188-196, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33458471

RESUMO

A complete process flowsheet to recover metal values from Sm2Co17-type magnet scrap was investigated. The magnet scrap was leached in chloride medium at pulp density of 2% (w/v) under the optimum conditions of 15% (v/v) HCl and 5% (v/v) H2O2 at 70 °C for 3 h, which yielded 98.5% Sm and 99% Co extractions. The full factorial Design of Experiment technique was adopted for the optimization of leaching conditions. Sm was selectively separated from the leach liquor as precipitated double salt using Na2SO4. The precipitated double sulfate was later converted to Sm-oxalate, which was subsequently calcined to produce pure Sm2O3. Following Sm separation, Fe was removed through precipitation by raising the pH to 3.0. For Cu and Co recovery, solvent extraction techniques using LIX 84I and Na-CYANEX 272, respectively, were followed. The McCabe-Thiele diagrams for extraction as well as stripping were presented for both Cu and Co.

17.
ACS Omega ; 6(2): 1108-1118, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33490770

RESUMO

The search for low-cost environmentally benign promising electrode materials for high-performance electrochemical application is an urgent need for an applaudable solution for the energy crisis. For this, the present attempt has been made to develop a scalable synthetic strategy for the preparation of pure and dual-phase copper oxide self-hybrid/self-assembled materials from a copper oxalate precursor using the calcination route. The obtained samples were characterized by means of various physicochemical analytical techniques. Notably, we found that the BET surface area and pore volume of copper oxides measured by N2 adsorption-desorption decrease with the elevation of calcination temperature. From the XRD analysis, we observed the formation of a Cu2O cubic phase at low temperatures and a CuO monoclinic phase at high temperatures (i.e., 450 and 550 °C). FTIR and RAMAN spectroscopy were employed for bonding and vibrational structure analysis. The self-assembled dual-phase copper oxide particle as a pithecellobium-type hierarchical structure was observed through SEM of the sample prepared at 350 °C. The surface morphological structure for the samples obtained at 450 and 550 °C was a bundle-like structure developed though columnar self-assembling of the particles. All the above techniques confirmed the successful formation of Cu2O/CuO nanoparticles. Afterward, the electrochemical properties of the as-synthesized copper oxides reinforced by introducing carbon black (10% wt) were explored via cyclic voltammetry, electrochemical impedance spectroscopy, and galvanometric charge-discharge analysis. The Cu2O system exhibits the maximum specific capacitance performance value of 1355 F/g, whereas in the CuO system (at 450 and 550 °C), it possesses values of 903 and 724 F/g at a scan rate of 2 mV/s. This study reveals that the electrochemical properties of Cu2O are better than those of the CuO nanoparticles, which could be ascribed to the high surface area and morphology. The present assessment of the electrochemical properties of the developed material could pave the way to a low-cost electrode material for developing other high-performance hybrid electrodes for supercapacitor or battery applications.

18.
ACS Appl Mater Interfaces ; 12(29): 32578-32590, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32589004

RESUMO

Co3O4-impregnated NiO-YSZ (yttria-stabilized zirconia) is a possible electrocatalyst for direct methane electrooxidation with both high catalytic activity and the ability to mitigate coking. The physical and electrochemical properties of Co3O4-impregnated NiO-YSZ anodes are investigated and benchmarked against NiO-YSZ and CeO2-impregnated NiO-YSZ anodes. The following methane electrooxidation activity trend: Co3O4-impregnated NiO-YSZ > CeO2-impregnated NiO-YSZ > NiO-YSZ with io (exchange current density) values of 88, 83, and 2 mA cm-2, respectively, is obtained in the high overpotential region. The high activity of Co3O4-impregnated NiO-YSZ is attributed to the changes in the electronic structure and microstructure with the incorporation of nickel into the lattice of Co3O4 as observed using X-ray photoelectron spectroscopy, temperature-programmed reduction, high-resolution transmission electron microscopy, and field emission scanning electron microscopy. Co3O4-impregnated NiO-YSZ also demonstrated the least coking during operation, confirming its utility as a methane electrooxidation catalyst.

19.
ACS Omega ; 5(3): 1287-1295, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32010797

RESUMO

The electrochemical energy conversions play an essential role in the production of sustainable and renewable energy. However, the performance is not up to the mark due to the absence of highly efficient and stable electrocatalysts. Recently, both 2D-matrix and single-atom catalysts (SACs) are two intense research topics in the field of electrocatalysis due to the high activity and stability and to maximize the utilization efficiency. Engineering the materials from 3D to 2D and modification from nanoparticles to single atoms have created a significant enhancement in the electrocatalytic activity. Hybridizing both the 2D matrix and SACs (2DM@SACs) creates a new electronic state in the materials, and that bequeaths with enhancing potentials toward the electrocatalytic activity. The strong covalent interaction between the 2D matrix and SACs tunes the intrinsic activity of the electrocatalysts. In this mini-review, we have discussed the different synthesis methods of 2DM@SACs with a focus on their electrochemical energy applications such as hydrogen evolution, oxygen evolution, oxygen reduction, and carbon dioxide reduction. This mini-review appraises the contribution to the rational proposal for the synthesis of perfect 2DM@SAC catalysts with their electrochemical properties toward energy conversion applications.

20.
RSC Adv ; 10(43): 25487-25495, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-35518591

RESUMO

This paper demonstrates a new and simplified configuration for capillary electrophoresis-amperometric detection (CE-AD) using a paper microfluidic chip incorporating inexpensive wax printing and screen printing based methods and then used for electrophoretic separation and simultaneous in-channel amperometric detection of three clinically relevant neurochemicals in a single run without using any decouplers. Detection of neurochemicals e.g., dopamine, epinephrine and serotonin is crucial for early prediction of neurological disorders including Parkinson's, Alzheimer's, dementia, as well as progressive neuro-psychiatric conditions such as depression, anxiety, as well as certain cardiovascular diseases. The plasma concentrations of such neurochemicals are as important as those present in cerebrospinal fluid (CSF) and can be useful for rapid and convenient biosensing. However, simultaneous detection of such neurochemicals in a complex mixture such as human serum requires their separation prior to detection. With the developed microchip, separation and detection of the neurochemicals were exhibited within 650 seconds without pre-treatment and the procedure was validated with spiked fetal bovine serum samples. Beside this, the developed paper microfluidic chip has potential to be integrated in point-of-care diagnosis with onsite detection ability. Moreover, the use of a straight channel capillary, a screen-printed carbon electrode without decoupler, in-channel amperometric detection and low sample volume requirements (2 µL) are shown as additional advantages.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...