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Topic Review
Antioxidants and Carbon-Based Electrodes
Antioxidants are compounds that prevent or delay the oxidation process, acting at a much smaller concentration, in comparison to that of the preserved substrate. Primary antioxidants act as scavenging or chain breaking antioxidants, delaying initiation or interrupting propagation step. Secondary antioxidants quench singlet oxygen, decompose peroxides in non-radical species, chelate prooxidative metal ions, inhibit oxidative enzymes. Based on antioxidants’ reactivity, four lines of defense have been described: Preventative antioxidants, radical scavengers, repair antioxidants, and antioxidants relying on adaptation mechanisms. Carbon-based electrodes are largely employed in electroanalysis given their special features, that encompass large surface area, high electroconductivity, chemical stability, nanostructuring possibilities, facility of manufacturing at low cost, and easiness of surface modification. Largely employed methods encompass voltammetry, amperometry, biamperometry and potentiometry. Determination of key endogenous and exogenous individual antioxidants, as well as of antioxidant activity and its main contributors relied on unmodified or modified carbon electrodes, whose analytical parameters are detailed. Recent advances based on modifications with carbon-nanotubes or the use of hybrid nanocomposite materials are described. Large effective surface area, increased mass transport, electrocatalytical effects, improved sensitivity, and low detection limits in the nanomolar range were reported, with applications validated in complex media such as foodstuffs and biological samples.
  • 1.5K
  • 12 Apr 2021
Topic Review
Polymer Electrolytes
Lithium-based electrolytes are, at least from a thermodynamic standpoint, the most suitable ion-transport materials for energy storage systems. However, lithium-based ionic conductors suffer from safety concerns, and the limited availability of lithium in the Earth’s crust is at the root of the need to consider alternative metal ions. Notably, sodium stands out as the sixth most-prevalent element; therefore, when considering mineral reserves, it as a very attractive candidate as an alternative to the status quo. Even if the specific energy and energy density of sodium are indeed inferior with respect to those of lithium, there is substantial economic appeal in promoting the use of the former metal in stationary energy storage applications. 
  • 1.5K
  • 12 Mar 2024
Topic Review
Electroreduction of CO2 toward High Current Density
Carbon dioxide (CO2) electroreduction offers an attractive pathway for converting CO2 to valuable fuels and chemicals. Despite the existence of some excellent electrocatalysts with superior selectivity for specific products, these reactions are conducted at low current densities ranging from several mA cm−2 to tens of mA cm−2, which are far from commercially desirable values. To extend the applications of CO2 electroreduction technology to an industrial scale, long-term operations under high current densities (over 200 mA cm−2) are desirable.
  • 1.5K
  • 05 May 2022
Topic Review
Control-Based 4D Printing
Building on the recent progress of four-dimensional (4D) printing to produce dynamic structures, this study aimed to bring this technology to the next level by introducing control-based 4D printing to develop adaptive 4D-printed systems with highly versatile multi-disciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics and other industries such as agriculture and microfluidics. This study introduced and analyzed adaptive 4D-printed systems with an advanced manufacturing approach for developing stimuli-responsive constructs that organically adapted to environmental dynamic situations and uncertainties as nature does. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This paper demonstrates the adaptivity of these systems via a combination of proprioceptive sensory feedback, modeling and controllers, as well as the challenges and future opportunities they present.
  • 1.5K
  • 28 Oct 2020
Topic Review
Electrochemical Energy Storage Devices
Among electrochemical energy storage (EES) technologies, rechargeable batteries (RBs) and supercapacitors (SCs) are the two most desired candidates for powering a range of electrical and electronic devices. The RB operates on Faradaic processes, whereas the underlying mechanisms of SCs vary, as non-Faradaic in electrical double-layer capacitors (EDLCs), Faradaic at the surface of the electrodes in pseudo-capacitors (PCs), and a combination of both non-Faradaic and Faradaic in hybrid supercapacitors (HSCs). EDLCs offer high power density but low energy density. HSCs take advantage of the Faradaic process without compromising their capacitive nature. Unlike batteries, supercapacitors provide high power density and numerous charge–discharge cycles; however, their energy density lags that of batteries. Supercapatteries, a generic term that refers to hybrid EES devices that combine the merits of EDLCs and RBs, have emerged, bridging the gap between SCs and RBs. 
  • 1.5K
  • 16 Jan 2024
Topic Review
Catalytic Cathodes for Na-CO2 Batteries
Na-CO2 batteries with high energy density are drawing tremendous attention because of their advantages of combining cost-effective energy conversion and storage with CO2 clean recycle and utilization. Nevertheless, their commercial applications are impeded by unsatisfactory electrochemical performance including large overpotentials, poor rate capability, fast capacity deterioration, and inferior durability, which mainly results from the inefficient electrocatalysts of cathode materials. 
  • 1.5K
  • 23 Jun 2021
Topic Review
Nanomaterials in Electrochemical Sensing Area
Recently, nanomaterials have received increasing attention due to their unique physical and chemical properties, which make them of considerable interest for applications in many fields, such as biotechnology, optics, electronics, and catalysis. The development of nanomaterials has proven fundamental for the development of smart electrochemical sensors to be used in different application fields such, as biomedical, environmental, and food analysis. In fact, they showed high performances in terms of sensitivity and selectivity. 
  • 1.5K
  • 06 Feb 2021
Topic Review
Electrochemical Bromofunctionalization of Alkenes
The electrochemical generation of highly reactive and hazardous bromine under controlled conditions as well as the reduction of surplus oxidizers and reagent waste has placed electrochemical synthesis in a highlighted position. In particular, the electrochemical dibromination and bromofunctionalization of alkenes and alkynes have received significant attention, as the forming of synthetically important derivatives can be generated from bench-stable and safe bromide sources under “green” conditions.
  • 1.5K
  • 17 Nov 2022
Topic Review
Development Aspects for Practical Non-aqueous Redox-Flow Batteries
Redox-flow cells can be divided into four basic types: all-liquid redox-flow batteries (ALRFBs), semi-solid redox-flow batteries (SSRFBs), hybrid redox-flow batteries (HRFBs), and single-flow batteries (SFB). These four basic types can be further classified by their cell separation techniques and membrane setups. They range from having no separation membrane to having up to three separation membranes in parallel.
  • 1.4K
  • 20 Feb 2023
Topic Review
The Rheological Phase Reaction Method
The term “rheology” stands for the study of a material’s flow behavior under applied deformation forces or stress. The Rheological Phase Reaction (RPR) method is considered a “pollution-less method” to prepare any metal oxides with high crystallinity, phase purity, and fewer agglomerations depending on the proper raw materials and the right temperature conditions are being chosen. 
  • 1.4K
  • 03 Feb 2023
Topic Review
Hydrogen Evolution Reaction and MXenes
Green hydrogen production via electrocatalytic water splitting paves the way for renewable, clean, and sustainable hydrogen (H2) generation. H2 gas is produced from the cathodic hydrogen evolution reaction (HER), where the reaction is catalyzed primarily from Pt-based catalysts under both acidic and alkaline environments. MXene is a 2D nanomaterial based on transition-metal carbide or nitride, having the general formula of Mn+1XnTx, where M = transition metal, X = C and/or N and Tx = surface termination groups such as F, O, OH and Cl.
  • 1.4K
  • 26 Dec 2022
Topic Review
Graphene-Based Cathode Materials for Lithium-Ion Capacitors
Lithium-ion capacitors (LICs) are attracting increasing attention because of their potential to bridge the electrochemical performance gap between batteries and supercapacitors. LICs are still impeded by their inferior energy density, which is mainly due to the low capacity of the cathode. Graphene-based nanomaterials have been recognized as one of the most promising cathodes for LICs due to their unique properties, and exciting progress has been achieved. 
  • 1.4K
  • 13 Dec 2021
Topic Review
Application of Mixed Potential Theory to Leaching
Leaching is a central unit operation in the hydrometallurgical processing of minerals, which often occurs by means of electrochemical reactions. Application of mixed potential theory to explain the kinetics of oxidative and reductive leaching processes is a useful concept in explaining observed results. Native metals, selected oxides, and most base metal sulfides are electron-conducting phases. For these minerals, leaching may take place by normal corrosion, passivation or galvanic couple mechanisms, which provide individual electrode kinetics enabling the calculation of mixed potentials and overall reaction kinetics. 
  • 1.4K
  • 08 Jul 2022
Topic Review
Applications of Electrosorption Technology in Water Treatment
The salt removal from water by using electrosorption has been studied since 1960s, and the application of this technology began in the mid-1990s when Lawrence Livermore National Laboratory developed the first set of electrosorption application devices in 1996.
  • 1.4K
  • 19 Aug 2022
Topic Review
Thermo-Electrochemical Cells for Harvesting Waste Heat
Thermo-electrochemical cells (also known as thermocells; TECs) represent a promising technology for harvesting and exploiting low grade waste heat (< 100-150ºC) ubiquitous in the modern environment. Based on temperature dependent redox reactions and ion diffusion, emerging liquid-state thermocells convert waste heat energy into electrical energy generating power at low costs, minimal material consumption and negligible carbon foot-print. Highest values of output power and cell potentials have been achieved for the redox ferri/ferrocyanide system and Co2+/3+, with great opportunities for further development in both aqueous and non-aqueous solvents. New thermoelectric applications in the field include wearable and portable electronic devices in the health and performance monitoring sectors; using body heat as a continuous energy source, thermoelectrics are being employed for long-term, continuous powering of these devices. Energy storage in the form of micro supercapacitors and in lithium ion batteries is another emerging application. For waste heat conversion (WHC) to partially replace fossil fuels as an alternative energy source, power generation needs to be commercially viable and cost-effective. Achieving greater power density and operations at higher temperatures will require extensive research and significant developments in the field.
  • 1.4K
  • 05 Sep 2022
Topic Review
Selenium-Based Cathode Materials for Lithium Batteries
Selenium (Se)-based cathode materials have garnered considerable interest for lithium-ion batteries due to their numerous advantages, including low cost, high volumetric capacity (3268 mAh cm−3), high density (4.82 g cm−3), ability to be cycled to high voltage (4.2 V) without failure, and environmental friendliness. However, they have low electrical conductivity, low coulombic efficiency, and polyselenide solubility in electrolytes (shuttle effect). These factors have an adverse effect on the electrochemical performance of Li-Se batteries, rendering them unsuitable for real-world use.
  • 1.4K
  • 09 Jun 2022
Topic Review
Direct-Hydrocarbon Proton-Conducting SOFCs
Solid oxide fuel cells (SOFCs) are promising and rugged solid-state power sources that can directly and electrochemically convert the chemical energy into electric power. Direct-hydrocarbon SOFCs eliminate the external reformers; thus, the system is significantly simplified and the capital cost is reduced. To reduce operating temperatures of SOFCs, intermediate-temperature proton-conducting SOFCs (P-SOFCs) are being developed as alternatives, which give rise to superior power densities, coking and sulfur tolerance, and durability. Due to these advances, there are growing efforts to implement proton-conducting oxides to improve durability of direct-hydrocarbon SOFCs.
  • 1.3K
  • 27 May 2021
Topic Review
Iron-Series Electrocatalysts for Water Splitting
The development of non-noble metal-based electrocatalysts with high performance for hydrogen evolution reaction and oxygen evolution reaction is highly desirable in advancing electrocatalytic water-splitting technology but proves to be challenging. One promising way to improve the catalytic activity is to tailor the d-band center. This approach can facilitate the adsorption of intermediates and promote the formation of active species on surfaces.
  • 1.3K
  • 26 Dec 2022
Topic Review
TMDs in Aqueous Zinc Ion Batteries
Owing to the unique layered structure and more desirable layer spacing, transition metal dichalcogenide (TMD) materials are considered as the comparatively ideal cathode material of ZIBs which facilitate the intercalation/ deintercalation of hydrated Zn2+ between layers.
  • 1.3K
  • 19 Apr 2022
Topic Review
Biochar in the Development of Electrochemical Printed Platforms
Biochar is a pyrolytic material with several environmental benefits such as reducing greenhouse gas emissions, sequestering atmospheric carbon and contrasting global warming. It has moved to the forefront for its conductivity and electron transfer properties, finding applications in the fabrication of electrochemical platforms. In this field, researchers have focused on low-cost biomass capable of replacing more popular and expensive carbonaceous nanomaterials (i.e., graphene, nanotubes and quantum dots) in the realization of sensitive cost-effectiveness and eco-friendly electrochemical tools. 
  • 1.3K
  • 14 Sep 2022
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