Enhanced Electrochemical Performance of NiMn Layered Double Hydroxides/Graphene Oxide Composites Synthesized by One-Step Hydrothermal Method for Supercapacitors.

This study aims to enhance the performance of supercapacitors, focusing particularly on optimizing electrode materials. While pure NiMn layered double hydroxides (LDHs) exhibit excellent electrochemical properties, they have limitations in achieving high specific capacitance. Therefore, this paper successfully synthesized composite materials of NiMn LDHs with varying loadings of graphene oxide (GO) using a hydrothermal method. Systematic physicochemical characterization of the synthesized materials, such as powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), and Raman spectroscopy, revealed the influence of GO doping on the microstructure and electrochemical performance of NiMn LDHs. Electrochemical tests demonstrated that the NiMn LDHs/GO electrode material exhibited optimal electrochemical performance with a specific capacitance of 2096 F g-1 at 1 A g-1 current density and 1471 F g-1 at 10 A g-1, when GO doping level was 0.45 wt %. Furthermore, after 1000 cycles of stability testing, the material retained 53.3 % capacitance at 5 A g-1, indicating good cyclic stability. This study not only provides new directions for research on supercapacitor electrode materials but also offers new strategies for developing low-cost and efficient electrode materials.

Comparative microstructural analysis of V2O5nanoparticles via x-ray diffraction (XRD) technique.

Vanadium pentoxide (V2O5) nanoparticles exhibit diverse properties and have been studied for a wide range of applications, including energy storage, catalysis, environmental remediation, and material enhancement. In this work, we have reported the synthesis of vanadium pentaoxide (V2O5) nanoparticles using hydrothermal method. Ammonium metavanadate (NH4VO3) was used as a source of vanadium. These syntheses were carried out at four different concentrations of vanadium source. The hydrothermal reaction was conducted at a temperature of 180 °C for a duration of 24 hours, followed by an additional 24 hours period of natural cooling. Four samples were annealed in air using a muffle furnace at 500 °C for five hours. The x-ray diffraction technique was used to study the structural aspects. A comparative analysis of the microstructure was conducted utilizing the Scherrer method, the Williamson-Hall method and its various models, size-strain analysis, and the Halder-Wagner method. The crystallite size and microstrain were determined using these distinct methods, revealing a systematic correlation between the crystallite size and microstrain obtained through the different techniques.

Fabrication of Highly Dispersed Ru Catalysts on CeO2 for Efficient C3H6 Oxidation.

Emissions of volatile organic compounds (VOCs) threaten both the environment and human health. To realize the elimination of VOCs, Ru/CeO2 catalysts have been intensively investigated and applied. Although it has been widely acknowledged that the catalytic performance of platinum group metal catalysts was highly determined by their dispersion and coordination environment, the most reactive structures on Ru/CeO2 catalysts for VOCs oxidation are still ambiguous. In this work, starting from Ce-BTC (BTC = 1,3,5-benzenetricarboxylic acid) materials, atomically dispersed Ru catalysts and agglomerated Ru catalysts were successfully created via one-step hydrothermal method (Ru-CeO2-BTC) and conventional incipient wetness impregnation method (Ru/CeO2-BTC), respectively. In a typical model reaction of C3H6 oxidation, atomically dispersed Ruδ+ species with the formation of abundant Ru-O-Ce linkages on Ru-CeO2-BTC were found to perform much better than agglomerated RuOx species on Ru/CeO2-BTC. Further characterizations and mechanism study disclosed that Ru-CeO2-BTC catalyst with atomically dispersed Ru ions and more superior low temperature redox performance compared to Ru/CeO2-BTC could better facilitate the adsorption/activation of C3H6 and the decomposition/desorption of intermediates, thus exhibiting superior C3H6 oxidation activity. This work elucidated the reactive sites on Ru/CeO2 catalysts in the C3H6 oxidation reaction and provided insightful guidance for designing efficient Ru/CeO2 catalysts to eliminate VOCs.

Synthesis of P-Rich Carbon Quantum Dots for Sensitive Fluorescent Detection of 2-Methylimidazole.

Using o-phenylenediamine as carbon source and phytic acid as phosphorus source, two P-rich carbon quantum dots RCDs and BCDs were synthesized successfully by changing the reaction temperature and time of hydrothermal method. It was found that RCDs with red emission could realize sensitive detection of 2-methylimidazole, and 2-methylimidazole had no obvious quenching effect on BCDs with blue emission, which made RCDs a sensitive, quick and selective fluorescence sensor for 2-methylimidazole detection. Under the optimal experimental conditions, the fluorescence intensity of RCDs decreased with the increasing of 2-methylimidazole concentration. The detection of 2-methylimidazole concentration by the carbon quantum dots sensor showed a good linear relationship in the range of 5 ~ 110 µM, and the low detection limit was 0.61 µM (S/N = 3). The sensor is able to detect 2-methylimidazole in lake water, enabling the application of real samples. The results show that this work provides a simple fluorescence method to detect 2-methylimidazole in water.

Enhancing Photoelectric Response of Self-powered UV and Visible Detectors Using CuO/ZnO NRs Heterojunctions.

Understanding the development and performance of UV photodetectors is crucial, given their extensive applications in both military and civilian sectors. The evolution of self-powered photodetectors, especially those based on heterojunction nanostructures, has demonstrated significant potential for enhancing both device efficiency and functionality. By exploring the effects of material composition and structural design, can optimize these devices for improved photoelectric response and energy efficiency. In this study, we prepared the CuO/ZnO NRs heterojunction photodetector on an ITO substrate to enhance photoelectric response of UV detectors. The fabrication process utilized the hydrothermal method and the spin coating technique. The effect of CuO concentration on the optical response of the photodetector under UV radiation at wavelengths of 405 nm and 385 nm was investigated. The samples were characterized using FESSEM, XRD, EDX, and UV-Vis spectra. The device is further distinguished by its standard I-V curves and photocurrent-time curves, which demonstrate the device's behavior under various light conditions. The prepared thin films are polycrystalline, with CuO layers displaying monoclinic phases and ZnO layers exhibiting a hexagonal wurtzite phase. All samples have the potential to exhibit photovoltaic properties and self-powered capabilities. Furthermore, the I-V curve confirms that the photocurrent mechanism of these junctions adheres to the recombination standard, in addition to demonstrating correction behavior. A sample with a CuO concentration of 0.1 M shows the highest photosensitivity, reaching 340,700%, and a photocurrent gain (Iph/Idark) of 3,408 when exposed to light irradiation at 405 nm. Additionally, it exhibits a rapid response time of 0.8 s.

Citrus Medica-derived Fluorescent Carbon Dots for the Imaging of Vigna Radiate Root Cells.

Bio-imaging is a crucial tool for researchers in the fields of cell biology and developmental biomedical sector. Among the various available imaging techniques, fluorescence based imaging stands out due to its high sensitivity and specificity. However, traditional fluorescent materials used in biological imaging often suffer from issues such as photostability and biocompatibility. Moreover, plant tissues contain compounds that cause autofluorescence and light scattering, which can hinder fluorescence microscopy effectiveness. This study explores the development of fluorescent carbon dots (Cm-CDs) synthesized from Citrus medica fruit extract for the fluorescence imaging of Vigna radiata root cells. The successful synthesis of CDs with an average size of 6.7 nm is confirmed by Transmission Electron Microscopy (TEM). The X-ray diffraction (XRD) analysis and raman spectroscopy indicated that the obtained CDs are amorphous in nature. The presence of various functional groups on the surface of CDs were identified by Fourier transform infrared (FTIR) spectra. The optical characteristics of Cm-CDs were studied by UV-Visible spectroscopy and photoluminescence spectroscopy. Cm-CDs demonstrated strong excitation-dependent fluorescence, good solubility, and effective penetration in to the Vigna radiata root cells with multicolor luminescence, and addressed autofluorescence issues. Additionally, a comparative analysis determined the optimal concentration for high-resolution, multi-color root cell imaging, with Cm-CD2 (2.5 mg/ml) exhibiting the highest photoluminescence (PL) intensity. These findings highlight the potential of Cm-CDs in enhancing direct endocytosis and overcoming autofluorescence in plant cell imaging, offering promising advancements for cell biology research.

Tailoring ZnS nanostructures through precipitation-cum-hydrothermal synthesis for enhanced wastewater purification and antibacterial treatment.

This study presents a novel blend of synthesis techniques for shape-controlled ZnS nanoparticles. Zinc sulfide (ZnS) nanoparticles with distinct morphologies cauliflower-like microstructures (∼4.5 µm) and uniform nanospheres (200-700 nm) were synthesized through an innovative blend of precipitation and hydrothermal techniques. Capping with polyvinylpyrrolidone (PVP) significantly decreased crystallite size (3.93 nm-2.36 nm), modulated the band gap (3.57 eV-3.71 eV), and dramatically influenced morphology, highlighting the novelty of shape-controlled synthesis and its impact on optoelectronic and functional properties. X-ray diffraction confirmed crystallinity and revealed the size-controlling influence of PVP. UV-vis spectroscopy suggested potential tuning of optical properties due to band gap widening upon PVP capping. Field-emission scanning electron microscopy (FESEM) unveiled distinct morphologies: cauliflower-like microstructures for ZnS and uniform nanospheres (200-700 nm) for PVP-ZnS. Both structures were composed of smaller spherical nanoparticles, demonstrating the role of PVP in promoting controlled growth and preventing agglomeration. High-resolution transmission electron microscope (HRTEM) images depicted that the majority of nanoparticles maintain a spherical shape, though slight deviations from perfect sphericity can be discerned. Fourier-transform infrared (FTIR) spectroscopy confirmed that successful PVP encapsulation is crucial for shaping nanospheres and minimizing aggregation through steric hindrance. Photocatalytic activity evaluation using methylene blue (MB) dye degradation revealed significantly faster degradation by PVP-ZnS under ultraviolet (UV) irradiation (within 60 min as compared to 120 min for ZnS), showcasing its superior performance. This improvement can be attributed to the smaller size, higher surface area, and potentially optimized band gap of PVP-ZnS. Additionally, PVP-ZnS exhibited promising antibacterial activity against S. aureus and P. aeruginosa, with increased activity at higher nanoparticle concentrations.

Antibacterial properties and application of Bi2Sn2O7/ZnO composite photocatalytic materials.

In this experiment, Bi2Sn2O7/ZnO composite photocatalytic materials were synthesized by a hydrothermal method and characterized by XRD, SEM, and EDS, etc. The prepared Bi2Sn2O7/ZnO has a nanorod structure and high phase purity. The photocatalytic antimicrobial performance of Bi2Sn2O7/ZnO against bacteria and fungi under visible light was significantly better than that of single Bi2Sn2O7 and ZnO. In particular, 1000 mg/L 1:3 Bi2Sn2O7/ZnO showed an antimicrobial rate of more than 97% against Escherichia coli, Staphylococcus aureus, and Candida albicans, which are widely present in the nature. The free radical trapping experiments were selected and the antimicrobial mechanism was investigated, and the results showed that the antimicrobial process of the Bi2Sn2O7/ZnO system was regulated by the free radicals such as ·OH, h+, and e-, which were generated by its unique photocatalytic activity. Finally, MTT cytotoxicity experiments demonstrated that the Bi2Sn2O7/ZnO composite was not toxic to cells. In addition, the antimicrobial performance of Bi2Sn2O7/ZnO on real livestock wastewater and the real-life application of the prepared Bi2Sn2O7/ZnO PCL composite antibiotic film for antimicrobial treatment of freshly cut fruits' surfaces under visible light were experimentally investigated. This study provides a new idea for Bi2Sn2O7/ZnO as a photocatalytic antimicrobial agent.

Black Phosphorus-Tungsten Oxide Sandwich-like Nanostructures for Highly Selective NO2 Detection.

Modern chemical production processes often emit complex mixtures of gases, including hazardous pollutants such as NO2. Although widely used, gas sensors based on metal oxide semiconductors such as WO3 respond to a wide range of interfering gases other than NO2. Consequently, developing WO3 gas sensors with high NO2 selectivity is challenging. In this study, a simple one-step hydrothermal method was used to prepare WO3 nanorods modified with black phosphorus (BP) flakes as sensitive materials for NO2 sensing, and BP-WO3-based micro-electromechanical system gas sensors were fabricated. The characterization of the as-prepared BP-WO3 composite through X-ray diffraction scanning electron microscopy and X-ray photoelectron spectroscopy confirmed the successful formation of the sandwich-like nanostructures. The result of gas-sensing tests with 2-14 ppm NO2 indicated that the sensor response was 1.25-2.21 with response-recovery times of 36 and 36 s, respectively, at 190 °C. In contrast to pure WO3, which exhibited a response of 1.07-2.2 to 0.3-5 ppm H2S at 160 °C, BP-WO3 showed almost no response to H2S. Thus, compared with pure WO3, BP-WO3 exhibited significantly improved NO2 selectivity. Overall, the BP-WO3 composite with sandwich-like nanostructures is a promising material for developing highly selective NO2 sensors for practical applications.

In Situ Self-Assembly of Nitrogen-Doped 3D Flower-like Hierarchical Porous Carbon and Its Application for Supercapacitors.

The hierarchical porous carbon-based materials derived from biomass are beneficial for the enhancement of electrochemical performances in supercapacitors. Herein, we report the fabrication of nitrogen-doped 3D flower-like hierarchical porous carbon (NPC) assembled by nanosheets using a mixture of urea, ZnCl2, and starch via a low-temperature hydrothermal reaction and high-temperature carbonization process. As a consequence, the optimized mass ratio for the mixture is 2:2:2 and the temperature is 700 °C. The NPC structures are capable of electron transport and ion diffusion owing to their high specific surface area (1498.4 m2 g-1) and rich heteroatoms. Thereby, the resultant NPC electrodes display excellent capacitive performance, with a high specific capacitance of 249.7 F g-1 at 1.0 A g-1 and good cycling stability. Remarkably, this implies a superior energy density of 42.98 Wh kg-1 with a power density of 7500 W kg-1 in organic electrolyte for the symmetrical supercapacitor. This result verifies the good performance of as-synthesized carbon materials in capacitive energy storage applications, which is inseparable from the hierarchical porous features of the materials.

Hydrothermally Grown Globosa-like TiO2 Nanostructures for Effective Photocatalytic Dye Degradation and LPG Sensing.

The rapid expansion of industrial activities has resulted in severe environmental pollution manifested by organic dyes discharged from the food, textile, and leather industries, as well as hazardous gas emissions from various industrial processes. Titanium dioxide (TiO2)-nanostructured materials have emerged as promising candidates for effective photocatalytic dye degradation and gas sensing applications owing to their unique physicochemical properties. This study investigates the development of a photocatalyst and a liquefied petroleum gas (LPG) sensor using hydrothermally synthesized globosa-like TiO2 nanostructures (GTNs). The synthesized GTNs are then evaluated to photocatalytically degrade methylene blue dye, resulting in an outstanding photocatalytic activity of 91% degradation within 160 min under UV light irradiation. Furthermore, these nanostructures are utilized to sense liquefied petroleum gas, which attains a superior sensitivity of 7.3% with high response and recovery times and good reproducibility. This facile and cost-effective hydrothermal method of fabricating TiO2 nanostructures opens a new avenue in photocatalytic dye degradation and gas sensing applications.

Improved Luminous Efficiency of AgInS2 Quantum Dots and Zeolitic Imidazolate Framework-70 Composite for White Light Emitting Diode Applications.

The application of multiple quantum dots (QDs) in the field of white light emitting diodes (WLEDs) is still an important challenge due to their low luminous efficiency and quenching phenomenon. In this paper, we prepared AgInS2 QDs/zeolitic imidazolate framework-70 (AIS/ZIF-70) composite by a microwave hydrothermal method. Owing to the high porosity and stability of ZIF-70, it could effectively prevent quenching issues due to the aggregation of QDs. Since the ZIF-70 and QDs were chemically bonded, the formation of the ZnS layer could effectively passivate the surface defect and thus the quantum yield reached 21.49 % in aqueous solution. The luminous efficiency (LE) of the assembled AIS/ZIF-based WLED was reinforced by 6.8 times with a molar ratio of AgIn/Zn=18, i. e. at 5.26 % molar fraction of ZIF-70. Moreover, the color rendering index (CRI) and correlated color temperature (CCT) of AIS/ZIF-based WLED were 84.3 and 3631 K, respectively, indicating its potential application in solid-state lighting.

Ce2(MoO4)3 synthesized with oleylamine and oleic acid as additives for photocatalysis: effect of preparation method.

Ce2(MoO4)3 was prepared using dielectric barrier discharge (DBD) plasma method, co-precipitation method and hydrothermal method, respectively, with water/ethanol (W/O) as solvent, oleylamine (OAm) and oleic acid (OAc) as additives. Preparation method showed significant influence on the morphological and structural properties, as well as photocatalytic performance. Ce2(MoO4)3 synthesized with DBD plasma (MO-P) was mainly flowerlike nanosheets, which were beneficial to promoting electron transfer and providing more space for catalytic activity. Also, MO-P samples exhibited more oxygen vacancies, which were conducive to the photocatalytic performance. What's more, MO-P showed lower PL intensity and narrow energy gap, which implied a slow photoelectron-hole pair recombination rate and an increased electron transfer rate. The degradation rate of methyl orange (50 mg/L) could achieve 98% within 12 min with 0.5 g/L MO-P. Hydroxyl radicals (·OH) and superoxide radicals (·O2-) played a major effect. Plasma synthesis method exhibited potential application prospect in photocatalysts preparation.

Multifunctional CoFe2O4/ZnO nanocomposites: Probing magnetic and photocatalytic properties.

Developing nanocomposites as efficient photocatalysts for eliminating hazardous contaminants is essential because of growing severity of water pollution. In this study, we have analysed the morphological, structural, magnetic, and optical properties of cobalt ferrite (CoFe2O4), and zinc oxide (ZnO) nanocomposites synthesized via hydrothermal approach and used for removal of rose bengal (RB) dye from contaminated water. X-ray diffraction (XRD) analysis of synthesized nanocomposite revealed two distinct phases that matched with CoFe2O4 and ZnO. Fourier Transform Infrared (FTIR) spectra enlightened Co-O, Fe-O, and O-Zn-O binding peaks in synthesized nanocomposites. The band gap of nanocomposite, as determined by UV diffuse reflectance spectroscopy (UV-DRS), varies from 3.19 to 3.25 eV. The wide band gap semiconductor (ZnO) is believed to be responsible for this transformation by introducing new sub-bandgap energy levels. X-ray photoelectron spectroscopy (XPS) has shown the roles of various ions. High-resolution transmission electron microscopy (HRTEM) analysis revealed spherical morphology of synthesized samples. The highest magnetism of pure CoFe2O4 was 34.61 emu/g, making it the most magnetic among all the synthesized materials. Furthermore, CoFe2O4/ZnO (1:4) nanocomposite exhibited the highest degradation of RB dye. The recombination of electron-hole pairs is inhibited by interfacial charge transfer provided by CoFe2O4 and ZnO. The results showed that CoFeZn14 nanocomposite is a promising candidate for wastewater treatment. CoFeZn14 demonstrated remarkable stability, showcasing its ability to be reused up to four times without compromising its efficiency. .

Ultrahigh-acetone-sensitivity sensor based on Pt-loaded TiO2porous nanoparticles synthesized via a facile hydrothermal method.

A simple hydrothermal method based on an orthogonal experimental design was used to synthesis Pt-loaded TiO2mesoporous nanoparticles in one step. The successful synthesis of Pt-loaded TiO2nanoparticles was demonstrated by various characterization methods. The effects of the modification of Pt and its explanation are described in detail by means of the test results. Through systematic gas-sensing tests, we found that the Pt-loaded TiO2nanoparticles outperform pure TiO2nanoparticles, with a high response value (S= 42.5) to 200 ppm acetone at 260 °C and with a film thickness of 0.45 mm, far superior to that of pure TiO2. The response time (8 s) and recovery time (11 s) of the material are also relatively good with excellent selectivity and long-term stability (30 days). The frequent use of acetone as an organic solution in factories and laboratories, as well as the possibility of making a preliminary diagnosis of diabetes by detecting acetone levels in exhaled gas, make this work promising for environmental monitoring and medical diagnosis.

Multifunctional natural derived carbon quantum dots from Withania somnifera (L.) - Antiviral activities against SARS-CoV-2 pseudoviron.

Natural carbon dots (NCQDs) are expediently significant in the photo-, nano- and biomedical spheres owing to their facile synthesis, optical and physicochemical attributes. In the present study, three NCQDs are prepared and optimized from Withania somnifera (ASH) by one-step hydrothermal (bottom-up) method: HASHP (without dopant), nitrogen doped HASHNH3 (surface passivation using ammonia) and HASHEDA (surface passivation with ethylenediamine). The HR-TEM images reveal that HASHP, HASNH3, HASHEDA are spherically shaped with 2.5 ± 0.5 nm, 4 ± 1 nm and 5 ± 2 nm particle size, respectively, whereas FTIR confirms the aqueous solubility and nitrogen doping. The XRD patterns ensure that the NCQDs are amorphous and graphitic in nature. Comparatively, HASHNH3 (32.5%) and HASHEDA (27.6%) portray better fluorescence quantum yield than HASHP (5.6%). The increase in quantum yield for the doped NCQDs can be attributed to the surface passivation using ammonia and ethylenediamine. Surface passivation plays a crucial role in enhancing the fluorescence properties of quantum dots. The introduction of nitrogen through ammonia and ethylenediamine provides additional electronic states, possibly reducing non-radiative recombination sites and hence boosting the QY. In addition, an antiviral study unveils the striking potential of surface passivated NCQDs to curb Covid-19 crises with around 85% inhibition of SARS-CoV pseudoviron cells, which is better in comparison to the non-doped NCQDs. Hence, to understand the paramount efficacy of these NCQDs, a hypothesis on their possible mechanism of action against Covid-19 is discussed.

Amorphous hollow manganese silicate nanosphere oxidase mimic for ultrasensitive and high-reliable colorimetric detection of biothiols.

Metal-based nanozymes with exceptional physicochemical property and intrinsic enzymatic properties have been widely used in industrial, medical, and diagnostic fields. However, low substrate affinity results in unsatisfying catalytic kinetic and instability in complicated conditions, which significantly decreases their sensitivity and reliability. Herein, an amorphous hollow manganese silicate nanosphere (defined as AHMS) has been successfully synthesized via a facile one-step hydrothermal method and utilized in the archetype for colorimetric detection of biothiols with high sensitivity and high reliability. The experimental data demonstrates that ultrafast affinity of the substrate contributes to enhanced sensitivity with outstanding catalytic kinetic features (Km = 27.1 µM) and low limit of detection (LODGSH = 20 nM). The designed sensor demonstrates a reliable applicability for analysis of biological liquids (fetal calf serum and Staphylococcus aureus) and design of visual logic gates. Therefore, AHMS provides a promising strategy for ultrasensitive and high-reliable biosensing.

Scaling-up of carbon dots hydrothermal synthesis from sugars in a continuous flow microreactor system for biomedical application as in vitro antimicrobial drug nanocarrier.

Carbon dots (CDs) are a new class of nanomaterials exhibiting high biocompatibility, water solubility, functionality, and tunable fluorescence (FL) property. Due to the limitations of batch hydrothermal synthesis in terms of low CDs yield and long synthesis duration, this work aimed to increase its production capacity through a continuous flow reactor system. The influence of temperature and time was first studied in a batch reactor for glucose, xylose, sucrose and table sugar precursors. CDs synthesized from sucrose precursor exhibited the highest quantum yield (QY) (175.48%) and the average diameter less than 10 nm (~6.8 ± 1.1 nm) when synthesized at 220°C for 9 h. For a flow reactor system, the best condition for CDs production from sucrose was 1 mL min-1 flow rate at 280°C, and 0.2 MPa pressure yielding 53.03% QY and ~ 6.5 ± 0.6 nm average diameter (6.6 mg min-1 of CDs productivity). CDs were successfully used as ciprofloxacin (CP) nanocarrier for antimicrobial activity study. The cytotoxicity study showed that no effect of CDs on viability of L-929 fibroblast cells was detected until 1000 µg mL-1 CDs concentration. This finding demonstrates that CDs synthesized via a flow reactor system have a high zeta potential and suitable surface properties for nano-theranostic applications.

Direct regeneration of spent LiFePO4 materials via a green and economical one-step hydrothermal process.

The rapid development of electronic devices, electric vehicles and mobile energy storage devices, has increasingly emphasized the shortage of lithium resources for us in lithium-ion batteries are developing rapidly. The key to the disposal of spent lithium-ion batteries is to carry out green and efficient regeneration. Herein, we propose a one-step hydrothermal process for the direct regeneration of spent LiFePO4. To reduce the Fe3+ in the spent LiFePO4, the hydroxyl group was oxidized to an aldehyde group via a decarburization reaction, with DL-malic acid utilized as a low-cost and environmentally friendly reducing agent. The effects of various different Li concentrations, hydrothermal times and hydrothermal temperatures on the performance of regenerated LiFePO4 were investigated. The results revealed optimal electrochemical performance under a Li concentration of 1.2 mol L-1, a hydrothermal time of 6 h, and a hydrothermal temperature of 100 °C. The cycling stability of LiFePO4 regenerated under these conditions considerably improved. The initial discharge specific capacity and the discharge specific capacity of the regenerated LFP after 200 cycles were 138.4 mAh g-1 and 136.6 mAh g-1. All coulomb efficiencies of the regenerated LFP were above 97.2 %, and the capacity retention rate was 98.7%. This developed method can therefore be considered a green and feasible means for regeneration of LiFePO4.

Non-radical-dominated catalytic degradation of methylene blue by magnetic CoMoO4/CoFe2O4 composite peroxymonosulfate activators.

In this study, magnetic CoMoO4/CoFe2O4 (CMO/CFO) nanospheres with a core-shell structure were synthesized via two-step hydrothermal methods. The obtained particles were employed as catalysts to activate peroxymonosulfate (PMS) and degrade methylene blue (MB). The physico-chemical characterizations of the synthesized CMO/CFO showed that the CMO shell contributed to the enhancement of redox conversion and the increase in the concentration of oxygen vacancies (OVs). By examining reactive oxygen species (ROS) in the CMO/CFO/PMS system, the MB degradation was dominated by a non-radical pathway, and 1O2 was identified as the most abundant ROS. Besides, the CMO/CFO exhibited faster reaction kinetics than the pristine CFO. Moreover, the magnetic properties guaranteed the recycling and reuse of CMO/CFO, and the removal rate of MB was maintained at ∼94% after continuous use five times. Both the tolerance to SO42-and the wide pH range where the material is applicable make it a promising catalyst for dyeing wastewater treatment.