Pyrochemical processing and molten-salt reactors have recently garnered significant attention as they are promising options for future nuclear technologies, such as those for recycling spent nuclear fuels and the next generation of nuclear reactors. Both of these technologies require the use of high-temperature molten salt. To implement these technologies, one must understand the electrochemical behavior of fission products in molten salts, lanthanides, and actinides. In this study, a rotating-disk-electrode (RDE) measurement system for high-temperature molten salts is constructed and tested by investigating the electrochemical reactions of Sm3+ in LiCl–KCl melts. The results show that the reduction of Sm3+ presents the Levich behavior in LiCl–KCl melts. Using the RDE system, not only is the diffusion-layer thickness of Sm3+ measured in high-temperature molten salts but also various electrochemical parameters for Sm3+ in LiCl–KCl melts, including the diffusion coefficient, Tafel slope, and exchange current density, are determined.
This study pioneers a transformative approach of discarded orange peels (Citrus sinensis) into highly porous carbon, demonstrating its potential application in energy storage devices. The porous carbon structure offers a substantial surface area, making it conducive for effective ion adsorption and storage, thereby enhancing capacitance. The comprehensive characterization, including X-ray diffraction, Fourier transform infrared, Raman spectroscopy, field emission scanning electron microscopy, and XPS verifies the material’s suitability for energy storage applications by confirming its nature, functional groups, graphitic structure, porous morphology and surface elemental compositions. Moreover, the introduced plasma treatment not only improves the material’s intensity, bending vibrations, and morphology but also increases capacitance, as evidenced by galvanostatic charge–discharge tests. The air plasma-treated carbon exhibits a noteworthy capacitance of 1916F/g at 0.05A/g in 2 M KOH electrolyte. long term cyclic stability has been conducted up to 10,000 cycles, the calculated capacitance retention and columbic efficiency is 92.7% and 97.6%. These advancements underscore the potential of utilizing activated carbon from agricultural waste in capacitors and supercapatteries, offering a sustainable solution for energy storage with enhanced performance characteristics.
In this study, polyimide (PI)-based activated carbon fibers (ACFs) were prepared for application as electrode materials in electric double-layer capacitors by varying the steam activation time for the PI fiber prepared under identical cross-linking conditions. The surface morphology and microcrystal structural characteristics of the prepared PI-ACFs were observed by field-emission scanning electron microscopy and X-ray diffractometry, respectively. The textural properties (specific surface area, pore volume, and pore size distribution) of the ACFs were calculated using the Brunauer–Emmett–Teller, Barrett–Joyner–Halenda, and non-local density functional theory equations based on N2/ 77 K adsorption isotherm curve measurements. From the results, the specific surface area and total pore volume of PI-ACFs were determined to be 760–1550 m2/ g and 0.36–1.03 cm3/ g, respectively. It was confirmed that the specific surface area and total pore volume tended to continuously increase with the activation time. As for the electrochemical properties of PI-ACFs, the specific capacitance increased from 9.96 to 78.64 F/g owing to the developed specific surface area as the activation time increased.
Energy storage is one of the leading problems being faced globally, due to the population explosion in recent times. The conventional energy sources that are available are on the verge of extinction, hence researchers are keen on developing a storage system that will face the upcoming energy needs. Supercapacitors, also known as ultracapacitors or electrochemical capacitors, are advanced energy storage devices characterised by high power density and rapid charge–discharge cycles. Unlike traditional batteries, supercapacitors store energy through electrostatic separation, offering quick energy release and prolonged operational life. They hold exceptional performance in various applications, from portable electronics to electric vehicles, where their ability to deliver bursts of energy efficiently complements or replaces conventional energy storage solutions. Ongoing research focuses on enhancing energy density and overall efficiency, positioning supercapacitors as pivotal components in the evolving landscape of energy storage technologies. A novel electrode material of NiO/CuO/Co3O4/rGO was synthesized which when used as a supercapacitor, the highest value of CS is 873.14 F/g which is achieved for a current density of 1 A/g under with an energy density of 190 Wh/kg and the highest power density of 2.5 kW/kg along with 87.3% retention after 5000 GCD cycles under 1 M KOH.
Flexible self-supported laser-induced graphene (LIG) electrode devices were facilely fabricated through laser ablation technique by employing commercial polyimide film as the precursor material. Compared with the widely used traditional glassy carbon electrodes, the resulted LIG electrodes displayed abundant porous structure and surface defects. Notably, the onestep yielded LIG electrode devices were endowed with large electrochemically active surface area and accelerated electron transfer ability. Benefiting from its superior electrochemical property, these unmodified LIG electrodes exhibited remarkable enhanced electrochemical oxidation reactivity toward the food additive molecule Allura Red. Based on the augmented oxidation signal of Allura Red molecules on the LIG electrodes, a novel electrochemical sensor with high sensitivity for the detection of Allura Red was successfully developed. The sensor demonstrated a linear detection range spanning from 5 nM to 1 μM and exhibited a detection limit as low as 2.5 nM. Besides, the sensitivity was calculated to be 240.62 μA μM−1 cm− 2. More importantly, the sensor manifested outstanding stability, reproducibility, and practicality, further emphasizing its potential for real-world application.
The presence of tetracycline (TC) has been detected in the human living environment, and its complex structure makes it difficult to degrade. The green and efficient utilization of electroactivated persulfate advanced oxidation technology for the degradation of tetracycline remains a challenge. In this study, N-doped reduced graphene oxide (N-rGO) was prepared using a hydrothermal treatment method with urea as the nitrogen source. Four different mass ratios of graphene oxide (GO) to urea were synthesized, and the optimal mass ratio was determined through degradation experiments of tetracycline. The N-rGO/EC/PMS three-dimensional electrocatalytic system was constructed, and the influence of the experimental data on TC degradation, such as initial pH, PMS dosage and voltage, was determined. Characterization analysis using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and other methods was conducted. The efficient catalytic ability of N-rGO was demonstrated through the generation of hydrogen peroxide ( H2O2) and consumption of peroxymonosulfate (PMS). The superiority of the three-dimensional (3D) electrochemical advanced oxidation process was proposed by combining different systems. Furthermore, the presence of hydroxyl radicals (.OH), persulfate radicals ( SO4 ·−), and singlet oxygen (1O2) was identified using electron spin resonance (ESR) technology. The utilization of N-rGO as a three-dimensional electrode, coupled with the advantages of PMS activation and electrochemical oxidation processes, is a promising method for treating organic pollutants in wastewater.
In this investigation, we synthesized a novel quaternary nanocomposite, denoted as RGO-Ba(OH)2/CeO2/TiO2, through a straightforward and cost-effective solid-state synthesis approach. The as-prepared composites underwent a series of comprehensive characterizations, including XRD, FTIR, TGA-DTA, XPS, SEM, EDAX, and TEM analyses, affirming the successful synthesis of a quaternary nanocomposite with well-interconnected nanoparticles, nanorods, and sheet-like structures. Further, our electrochemical performance evaluations demonstrated that the electrochemical capacitance of the RGO-Ba(OH)2/CeO2/ TiO2 nanocomposite achieved an impressive value of 445 F g− 1 at a current density of 1.0 A g− 1, particularly when the mass ratio of CeO2 and TiO2 was maintained at 90:10. Furthermore, the specific capacitance retained a remarkable 65% even after 2000 cycles at a current density of 6 A g− 1 in a 3 mol KOH electrolyte. Comparatively, this outstanding electrochemical performance of the RGO-Ba(OH)2/CeO2/TiO2 (90:10) nanocomposite can be attributed to several factors. These include the favorable electrical conductivity and large specific surface area provided by graphene, TiO2, and Ba(OH)2, the enhanced energy density and extended cycle life resulting from the presence of CeO2, and the synergistic contributions among all four components. Therefore, the RGO-Ba(OH)2/CeO2/TiO2 nanocomposite emerges as a highly promising electrode material for supercapacitors.
In recent times, there has been a significant demand for supercapacitors in energy storage applications due to their rapid charging– discharging capabilities, high power density, and excellent stability. Nevertheless, the synthesis of electrode materials with a substantial surface area, exceptionally high porosity, and superior electrochemical performance is still challenging. Activated carbons with a distinctive porous structure and exceptional electrochemical properties emerged as promising electrode materials for supercapacitors. In this study, we used a porous activated carbon (PAC) derived from petroleum coke followed by KOH activation as an efficient anodic electrode material. The ultra-high Brunauer–Emmett–Teller surface area of 2105.6 m2 g− 1 with stacked layers of carbon atoms arranged in a two-dimensional hexagonal structure makes the PAC an efficient candidate for a supercapacitor electrode. The PAC delivers a specific capacitance of 470 F g− 1 at a current density of 0.5 A g− 1 over a potential window of 0 to −1 V. The excellent cycling stability in a three-electrode setup with a capacitance retention of ⁓98% even at a high current density of 10 A g− 1 makes the PAC a potential anodic electrode material for high-performance supercapacitor applications.
The waste secondary battery contains a significant amount of valuable metals, making its recycling highly desirable. However, conventional chemical methods for recycling are environmentally unfriendly and cost-ineffective. Rather than the chemical method, this paper deals with a mechanical method for recovering electrode materials from waste secondary batteries by blowing pressurized air onto the interface area between the electrode and the separator. Especially, in this study, the effective blowing angle were searched by simulating the separation of the electrode material from the separator through 1-way fluid structure interaction analysis based on the Cohesive Zone Modeling technique.
A glassy carbon electrode modified with a composite consisting of electrodeposited chitosan and carboxylated multi-walled carbon nanotubes (e-CS/MWCNTs/GCE) was used as a working electrode for simultaneous determination of dopamine (DA), serotonin (5-HT) and melatonin (MT), which were related to circadian rhythms. The electrochemical characterizations of the working electrode were carried out via electrochemical impedance spectroscopy and chronocoulometry. It was found that electrochemical modification method, that was cyclic voltammetry, may can cause continuous CS polymerization on MWCNTs surface to form a dense membrane with more active sites on the electrode, and the electrochemically active surface area of e-CS/MWCNTs/GCE obtained was about 7 times that of GCE. The electrochemical behaviour of DA, 5-HT and MT on working electrode were carried out via differential pulse voltammetry and cyclic voltammetry. The results showed that e-CS/MWCNTs/GCE solved the problem that the bare electrode could not detect three substances simultaneously, and can catalyze oxidation potential difference as low as 0.17 V of two substances reaction at the same time, indicating very good electrocatalytic activity. By optimizing the detection conditions, the sensor showed a good linear response to DA, 5-HT and MT in the range of 20-1000 μmol/L, 9-1000 μmol/L and 20-1000 μmol/L, and the detection limits were 12 μmol/L, 10 μmol/L and 22 μmol/L (S/N = 3), respectively. In addition, the proposed sensor was successfully applied to the simultaneous detection of DA, 5-HT and MT in human saliva samples.
In the present study, an innovative electrochemical sensing platform was established for sensitive detection of NO2 —. This sensor was developed using CoFe alloy encapsulated in nitrogen-doped carbon nanocubes (named as CoFe@NC-NCS), synthesized through the calcination of polydopamine-coated CoFe Prussian-blue analogues (CoFe-PBA@PDA). The morphological and electrochemical characterization reveals that the CoFe@NC-NCS possesses high electrocatalytic activity for electrochemical quantitation of NO2 —, ascribed to the huge surface area and plentiful active positions, benefiting from the porous, hollow, and core–shell structure of CoFe@NC-NCS. Under the optimal conditions, CoFe@NC-NCS/GCE possessed remarkable sensing performance for NO2 — with wide liner ranges and a detection limit of 0.015 μM. NO2 — recovery experiments in real samples exhibited recoveries in the range of 98.8–103.5%. Hence, the CoFe@NC-NCS shows great promise for the construction of electrochemical sensor with more potential application.
The dyeing process is a very important unit operation in the leather and textile industries; it produces significant amounts of waste effluent containing dyes and poses a substantial threat to the environment. Therefore, degradation of the industrial dye-waste liquid is necessary before its release into the environment. The current is focusing on the reduction of pollutant loads in industrial wastewater through remediating azo and thiazine dyes (synthetic solutions of textile dye consortium). The current research work is focused on the degradation of dye consortium through photo-electro-Fenton (PEF) processes via using dimensionally stable anode (Ti) and graphite cathode. The ideal conditions, which included a pH of 3, 0.1 (g/L) of textile dye consortium, 0.03 (g/L) of iron, 0.2 (g/L) of H2O2, and a 0.3 mAcm-2 of current density, were achieved to the removal of dye consortium over 40 min. The highest dye removal rate was discovered to be 96%. The transition of azo linkages into N2 or NH3 was confirmed by Fourier transforms infra-red spectroscopic analysis. PEF process reduced the 92% of chemical oxygen demand (COD) of textile dye consortium solution, and it meets the kinetics study of the pseudo-first-order. The degradation of dye through the PEF process was evaluated by using the cyclic voltammetric method. The toxicity tests showed that with the treated dye solution, seedlings grew well.
Energy storage for sustainable development and progress of power production industries is vitally important. The energy storage devices are under extensive research from last three decades to ensure the hand-on-hand coordination with power supply phenomenon and to reduce the energy loses in lines. The cost-effective materials are still highly demanding as an electrode material for energy storage devices. Biomass-derived carbon materials are best candidates due to their low cost, relatively high abundance, pollution-free nature. Here, we are reporting a facile two-step green approach to convert Himalayan horse chestnuts (HHCNs) into activated carbon materials. In first step, grinding and pyrolysis of the HHCNs were carried out, and then activation was performed using KOH to enhance the pore density and surface area. HHCNs-derived carbon was utilized as an electrode in electrical double-layer capacitors (EDLCs) with 1 M H2SO4 as an electrolyte. The macroporous structure along with hierarchical porous network acts as an efficient source of transportation of charges across the electrode and separator. Cyclic voltammetry test was taken from 10 to 100 mV/s current and within a range of 0–1 V applied potential; approximately rectangular CV shown mirror response towards current and shown typical EDLCs properties. The proximate analysis confirms the presence of heteroatoms like sulfur, oxygen, and nitrogen which act as carbon dopants. The wettability of HHCNs-derived carbon enhanced due to the various types of oxygen functionalities inherited from the lignin skeletal part. The nitrogen content is primarily responsible for the pseudo-capacitive behavior of HHCNs-codoped carbon. HHCNs-derived activated carbon materials has emerged as a promising electrode material for energy storage applications.
Heavy metal wastewater containing cobalt (Co2+) has received more attention as an environment issue, which is released from electroplating processes, battery materials industries, nuclear power plants, etc. Especially, cobalt exposed to high-temperature and high-pressure environment during the operation of a nuclear power plant to form corrosion products and forming a chalk river unidentified deposit (CURD) along with radioactive materials generated in cooling water pipes. Cobalt present in the oxide film is mainly Co-60, which emits radiation and causes increased radiation exposure to workers, and efficient management is essential. In this study, we demonstrated the performance of copper hexacyanoferrate (CuHCF) electrodes in a capacitive deionization (CDI) system for Co2+ ions removal. The structure and chemical status of CuHCF used as an electrode material were characterized, and electrochemical properties were evaluated. This study showed that Co2+ ions could be efficiently removed in aqueous solutions using CuHCF electrodes. It has been experimentally shown that the ion removal mechanism is driven by the insertion of Co2+ ions within the CuHCF lattice channels. The deionization capacities in 20 and 50 mg-Co2+ L-1 aqueous solutions were 141.62 and 156.85 mg g-1, respectively, and the corresponding charge efficiencies (Λ) were 0.55 and 0.68, respectively. Thus, we suggest that an electrochemically driven process using CuHCF can usefully remove Co2+ ions from wastewater.
The development of separation method of radioactive tritium is imperative for treating tritiumcontaminated water originating from nuclear facilities. Polymer electrolyte membrane electrolysis technology represents a promising alternative to conventional alkaline electrolysis for tritium enrichment. Nevertheless, there has been limited research conducted thus far on the composition of membrane electrode assemblies (MEAs) specifically optimized for tritium separation, as well as the methods used for their fabrication. In this study, we conducted an investigation aimed at optimizing MEAs specifically tailored for tritium separation. Our approach involved the systematic variation of MEA components, including the anode, cathode, porous transport layer, and electrode formation method. The water electrolysis efficiency and the H/D separation factor in deuterated water (1%) were evaluated with respect to both the preparation method and the composition of the MEA. To assess the long-term stability of the MEAs, changes in cell voltage, resistance, and the active electrode area were analyzed using impedance analysis and cyclic voltammetry. Furthermore, we examined H/D separation factor both before and after degradation. The results showed that MEAs with different anode/cathode configurations and electrode formation methods improved the electrolysis efficiency compared to commercial MEAs. In addition, the degree of change in the resistance value was also different depending on the electrode formation method, indicating that the electrode formation method has a significant impact on the stability of the electrolysis system. Therefore, the study showed that the efficiency and long-term stability of the water electrolzer can be improved by optimizing the MEA fabrication method.
Graphene is a suitable transducer for wearable sensors because of its high conductivity, large specific surface area, flexibility, and other unique considerable features. Using a simple, fast galvanic pulse electrodeposition approach, a unique nonenzymatic glucose amperometric electrode was successfully developed based on well-distributed fine Cu nanoparticles anchored on the surface of 3D structure laser-induced graphene. The fabricated electrode allows glucose detection with a sensitivity of 2665 μA/mM/cm2, a response time of less than 5 s, a linear range of 0.03–4.5 mM, and a LOD of 0.023 μM. It also detects glucose selectively in the presence of interfering species such as ascorbic acid and urea. These provide the designed electrode the advantages for glucose sensing in saliva with 97% accuracy and present it among the best saliva-range non-enzymatic glucose sensors reported to date for real-life diagnostic applications.