Ionics最新文献

Photocatalysis is one of the potential applications for environmental cleanup with unique properties like thermal, optical, electrical and structural properties. A facile green synthesis method was employed to synthesize Bi₂O₃ nanoparticles using Costus igneus leaf extract as a fuel for combustion synthesis. Costus igneus leaf extract was used as a natural source of reducing agent, capping, and stabilizing agents in this study which is successfully synthesize the bismuth oxide nanostructures. Green synthesis of Bi₂O₃ nano particles are very effective due to its advantageous characteristics such as non-toxicity, environmentally friendly synthesis, cost-effectiveness and the ability to achieve uniform particle formation. The calcinated product was characterized using spectroscopic techniques namely X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDXS). The synthesized Bi₂O₃ nanomaterials were subjected for photocatalytic property using methylene blue as a model organic pollutant present in waste water. The superb photocatalytic activity of the nanoparticles has its unique features, i.e., large surface area, defective states structure, visible-light-triggered band, good electrical conductivity. These factors enhance the light-harvesting, charge-separation, electron-excitation and charge transport properties of the synthesized bismuth oxide NPs. The study revealed that Bi₂O₃ nanoparticles showed 98% degradation efficiency within two hours of visible light irradiation. Furthermore, variations of pH and dye concentration parameters were performed to optimize the photodegradation efficiency of the as synthesized Bi₂O₃ nanoparticles. All of these factors work together to make environmental friendly Bi₂O₃ nanoparticles for wastewater treatment applications.

Exploring promising cathode materials is important for the development of zinc-ion batteries (ZIBs). In this work, the cubic spinel ZnMnO₃ material was prepared via a simple carbonate co-precipitation method, and the effect of sintering temperature (500, 600, 700, and 800 ℃) on the morphologies and electrochemical properties of ZnMnO₃ has been studied. Among the four samples, the ZnMnO₃ sample prepared at a sintering temperature of 600 °C (ZMO113-600) exhibits the most uniform spherical morphology and the most excellent zinc storage performance. It delivers an initial discharge capacity of 184.7 mAh g⁻¹ at a current density of 0.2 A g⁻¹ and a reversible capacity of 118.6 mAh g⁻¹ after 300 cycles. Even at 1.0 A g⁻¹, it still provides a reversible capacity of 51.2 mAh g⁻¹. The ex situ XRD result exhibits that the ZMO113-600 has excellent structural stability during cycling. In addition, the zinc-ion diffusion coefficient for the ZMO113-600 electrode is in a range of 1.47 × 10⁻⁹–3.16 × 10⁻⁹ cm² s⁻¹. This work offers a promising avenue for the development of cost-effective and high-performance cathode materials for ZIBs.

Li₃VO₄, characterized by its high theoretical capacity and minimal volume expansion, emerges as a promising anode material for lithium-ion batteries (LIBs). However, challenges such as poor electrical conductivity and morphological control hinder its practical application. In this study, we synthesized a homogeneous Li₃VO₄ precursor via a hydrothermal method, ensuring uniform complexation of lithium and vanadium sources. During subsequent spray pyrolysis, the Li₃VO₄ precursor templated the directional adsorption of Ni, facilitating the in situ transformation of the Ni source into nanoparticles and yielding Li₃VO₄-0.50Ni porous microspheres. These microspheres possess an exceptionally large specific surface area of 130.0 m² g⁻¹, enhancing electrolyte contact and reaction kinetics. The incorporation of Ni improves the electrical conductivity of Li₃VO₄ and, in conjunction with dispersed Ni and carbon, mitigates Li₃VO₄ particle aggregation. As a result, Li₃VO₄-0.50Ni demonstrates a discharge capacity of 433.8 mAh g⁻¹ after 3000 cycles at a high current density of 4.0 A g⁻¹, with a capacity retention of approximately 93.3%. This work underscores the potential of Li₃VO₄-0.50Ni as a robust anode material for high-performance LIBs.

The application of nuclear energy plays a crucial role in the advancement of global energy systems; however, sustainable development is inherently linked to the effective management of high-level waste produced by nuclear power generation. The disposal of nuclear waste involves encapsulation to create a stable waste form that is buried deep within geological repositories, ensuring ecological separation from human activities. Consequently, the corrosion resistance of the encapsulated material is vital for preventing leakage. This study examines the embedding properties of iron phosphate glass–coated LaPO₄ ceramics and evaluates the impact of corrosion factors such as bentonite, humic acid, and groundwater. The corrosion mechanisms were analyzed under acidic, neutral, and alkaline conditions. It was determined that the glass solidification can be embedded at a maximum concentration of 30 wt.%, with bulk density increasing alongside the embedding ratio. Notably, bentonite and glass solidification exhibit greater reactivity in acidic environments compared to neutral and alkaline conditions. Additionally, the glass solidification materials undergo hydration due to groundwater influence, leading to the corrosion of the glass surface and the formation of new crystalline phases, including H₄P₂O₆·2H₂O, Fe₅(PO₄)₃(OH)₅·2H₂O, and rhombohedral calcium zeolite (Ca₄Al₈Si₈O₃₂·8H₂O). The corrosion rate analysis indicates that lower pH levels correlate with increased corrosion rates in acidic conditions, particularly in the absence of humic acid. These findings provide a robust foundation for the future development of underground laboratories and the advancement of geological disposal technologies for high-level waste.

The cheap and massive residual carbon (RC) from coal gasification slags (CGSs) has been transformed into the carbon electrode material in supercapacitors through one-step low-temperature KOH-K₂CO₃ molten salt synergistic activation. Under the conditions of RC to the molten salt mass ratio of 1:2, an activation temperature of 400 °C, a series of activated products (ARCX) have been prepared by tuning the activation time (X = 1, 2, 3, 4 or 5 h). The electrochemical measurement results showed that the ARC3 exhibited the most excellent performance among the activated samples. At a current density of 0.2 A/g, the specific capacitance of ARC3 reached 249.5 F/g. By using the ARC3 as electrode active materials to assemble a symmetrical supercapacitor (ARC3//ARC3), its energy density was 7.3 Wh/kg at a power density of 250 W/kg, with the capacitance retention rate of ARC3//ARC3 remaining at 99% even after 10,000 charge–discharge cycles. For the ARC3, the unique structures formed from the coordinated pore-forming effects of KOH-K₂CO₃ eutectic salt induced the excellent performance, including high specific surface areas (715.08m²/g), appropriate hierarchical pore structure, and abundant surface oxygen-containing functional groups on the carbon surfaces. This work provides a completely new strategy to construct carbon electrode materials using CGSs or the other carbonate solid wastes as raw materials.

The use of activated coconut shell charcoal (ACSC) was explored as a cost-effective and viable alternative to platinum (Pt) counter electrodes (CE) in CdS quantum dot–sensitized solar cells (QDSSCs). The photovoltaic performances of QDSSCs with newly fabricated ACSC CEs by spraying method and Pt CEs were evaluated using current density–voltage measurements under 100 mWcm⁻² light illumination. While the QDSSC with a Pt CE showed an efficiency of 1.26%, the QDSSC with an ACSC CE, with an optimal thickness of 25 μm, corresponding to a spray time of 60 s, showed an efficiency of 2.93%, demonstrating a more than two-fold increase in the efficiency. The physicochemical parameters of ACSC CEs were analyzed using FTIR, Raman, X-ray diffraction, cyclic voltammetry (CV), and Tafel characterization. CV, Tafel, and electrochemical impedance (EIS) analysis confirmed the superior electrocatalytic activity of the ACSC CE compared to the Pt CE for QDSSCs. The efficiency enhancement can be attributed to the increased photocurrent density due to the superior electrocatalytic activity of ACSC, which promotes efficient polysulfide reduction at the electrolyte/counter electrode interface. The porous nature of ACSC provides an increased specific surface area, facilitating redox reactions and improving the interaction between the electrolyte and the counter electrode. Additionally, the enhanced charge transfer capabilities of the ACSC-based counter electrode contribute to efficient electron transport and reduced recombination losses. These properties collectively optimize the cell’s performance by ensuring effective energy conversion. Consequently, ACSC is emerging as a promising novel material for counter electrodes in QDSSCs.

Graphical Abstract

Lithium-ion battery (LIB) is the mainstream energy storage technology (ESS) technology in this market, mainly because it has several advantages such as long lifetime, high density and capacity, and low self-discharging. Despite that, LIB is still sensitive to failures, and if it is not well managed, several types of abuse can be observed and cause performance and security issues. Therefore, it is essential to understand the main abuses, their causes, consequences, and how they happen to prevent them. Thus, this paper presents a contribution of two steps: firstly, it demonstrates the study of five applications of external short-circuit (ESC) experiments in 18650 LIB. Then, a random forest mechanism was applied to classify the conditions that determine the intensity of the consequences of the ESC. In the first part, the following experiments have been performed: (I) varying initial voltage (from 3.5 to 4.2 V), (II) changing the time between ESC with a relaxing time (2, 10, 20, 30, and 60 s), (III) varying capacity of the cell (20 mAh, 400 mAh, 940 mAh, 1202 mAh, and 1750 mA), (IV) varying external resistance (from 50 to 250 m(Omega ) with 50 m(Omega ) step), and (V) varying the ambient temperature (30 (^{circ })C, 40 (^{circ })C, 50 (^{circ })C, 60 (^{circ })C, and 70 (^{circ })C). The results indicate that the ESC current curve comprises four stages. The temperature increases significantly during the high current flow in the cell. In addition, the external resistance, the time of the ESC, the ambient temperature, the cell’s capacity, and the state of charge (SOC) play a vital role in the ESC’s intensity and the ESC current’s magnitude. The cell current is shown to be the main parameter used for ESC prevention mechanisms because it represents a similar behavior for almost every cause of ESC. Despite that, this work presents different magnitudes of the current curve depending on the causes and criticality of the ESC. Therefore, the information and expertise collected from the experiments can be used for machine learning prevention mechanisms to monitor battery abuses and failures in the first stage without the demand for new sensors and hardware, which is the second contribution of this work. It consists of applying a random forest mechanism to identify the causes/conditions of the ESC based on the main signals collected from the batteries. The results indicated that the proposed model can estimate the initial conditions of the ESC up to 0.99 of R2.

A new strategy has been made to investigate low-cost porous carbon electrode material by using bio-waste raw date seeds activated with potassium hydroxide (KOH) to synthesize porous carbon cobalt oxide composite (PCCo) using facile one-step carbonization and to achieve high specific capacitance. The characterization of PCCo composite was done by powder X-ray diffraction, Fourier transform infrared spectrometer, field emission scanning electron microscopy, high-resolution transmission microscopy, Brunauer–Emmett–Teller (BET), and Raman spectroscopy techniques to confirm the chemical changes, morphology, and structural phase. It is observed that there is a high specific surface area (397 m² g⁻¹) and an abundant mesopores for PCCo composite. This hierarchical morphology structure offers good ion/electron transport channels for better electrochemical characteristics. The maximum specific capacitance was found to be 496 F/g at a scan rate of 10 mV/s, and also from the galvanostatic charge–discharge curve, it was 671 F/g at a current density of 1.5 A/g. The fabricated SSC PCCo-0.4//PCCo-0.4 device provides an energy density of 47.4 Wh kg⁻¹ and a power density of 853.2 W kg⁻¹ with a capacitance retention of 84.4% and a coulombic efficiency of 97% even after 5000 cycles. These results suggest that porous carbon composites are cost-effective, technologically unique, and eco-friendly for environmental supercapacitor applications.

Graphical abstract

Scheme: Schematic depicted of the synthesis of PCCo-0.4 composites by one-step carbonization and activation process from date seed and cobalt oxide (Co₃O₄).

Titanium dioxide (TiO₂) has attracted widespread attention as a promising alternative anode for Li-ion batteries (LIBs) due to its low volume change, excellent operation safety, good discharge potential, green technology, and low cost. In this work, a TiO₂ film was created on a Ti substrate by a one-step micro-arc oxidation (MAO) technique in a phosphate-based electrolyte, and it is specifically utilized as a binder-free anode for LIBs. The battery performance demonstrated a high sustained capacity of 270 µAh/cm² at a current density of 50 µA/cm², attributed to the porous morphology of the TiO₂ sample prepared at an optimized voltage, and excellent cycling stability over 200 cycles. Moreover, the capacity was restored to 90% of its initial capacity during cycling at a high current density of 500 µA/cm², illustrating good rate capability. Overall, the porous structure of TiO₂, along with the channels and cavities generated during the MAO process, serves as penetration pathways for lithium ions and provides surface-active sites for electrochemical reactions. This study presents a high-performance, cost-effective approach to developing binder-free anodes for LIBs with superior performance.

Nowadays, the advancement of eco-friendly, clean, sustainable and renewable new energy has emerged as a research priority for scientists worldwide. Electrolytic water technology is founded on the principle of electrochemical or photoelectric decomposition of water, is deemed as one of the most promising and most feasible approaches to reach industrial production. Traditional OER (oxygen evolution reaction) electrocatalysts like IrO₂ and RuO₂ are beset by high costs and vulnerability to poisoning. Hence, it is essential to develop more economical, more stable and more efficient materials for the application of OER reactions. In this study, a series of AQ-doped (AQ = anthraquinone) MOF-74 materials were fabricated through a one-step solvothermal approach. The surface loading of the conjugated organic small molecule AQ on CoNi-MOF-74 is capable of effectively boosting the inadequate electrical conductivity of the bulk MOF material, thus significantly enhancing the performance of OER. The optimized ratio of material composition of AQ20@MOF-74 displayed significantly enhanced OER activity. with a lower overpotential of 272 mV at 10 mA cm⁻² and a smaller Tafel slope of 78 mV dec⁻¹. The research findings presented in this thesis provide a novel approach for the design and optimization of highly efficient OER electrocatalysts based on MOFs.