Precipitation Method Research Articles

New quasi-Co/Cu-MOF nanozyme coupled with entropy-driven DNA amplification cascades for highly sensitive electrochemical aptamer growth differentiation factor 15 assay

BackgroundThe monitoring of concentration variation of the newly developed growth differentiation factor 15 (GDF15) biomarker in human serum is of great significance for diagnosing cardiovascular diseases. Current methods for the detection of the GDF15 protein mainly are based on antibody-assisted immunoassays, which encounter the limitations in terms of sensitivity, complexity and costs. The development of simple and sensitive biosensors for GDF15 can therefore facilitate the diagnosis of cardiovascular diseases. ResultsA new bimetallic quasi-Cu/Co-MOF nanozyme with high catalytic performance for electrochemical reduction of H2O2 is synthesized via simple one-step precipitation and low-temperature calcination method. Such nanozymes are further employed as amplification tags and coupled with cyclic entropy-driven DNA signal enhancement strategies to construct ultrasensitive aptamer-based biosensor for detecting GDF15 in human serums. GDF15 molecules associate with two aptamers and release the ssDNA trigger sequences via target-binding induced displacement reaction. These ssDNAs subsequently initiate cyclic DNA-fueled strand displacement and catalytic hairpin assembly (CHA) reaction cascades for confining many quasi-Cu/Co-MOF nanozymes on sensor electrode, which yield drastically amplified H2O2 reduction current for detecting GDF15 down to 0.12 pg mL−1 with a dynamic range of 0.5 pg mL−1 to 20 ng mL−1. The electrochemical aptasensor also presents good reproducibility and selectivity and exhibits the capability to detect GDF15 in diluent serums. SignificanceOur aptamer-based GDF15 protein electrochemical assay clearly outperforms current existing antibody-based methods and the quasi-Cu/Co-MOF nanozyme/entropy-driven cascaded signal amplification means can be used as a universal strategy for sensitive monitoring of different biomolecular markers for diverse applications.

Production of Nattokinase from Bacillus amyloliquefaciens MRS18: A Bacterial Strain Isolated from Fermented Beans.

Nattokinase (NK) is a naturally occurring fibrinolytic protease enzyme obtained from the traditional Japanese food called Natto and has several uses in the pharmaceutical and medical industries. Nowadays, the most often used thrombolytic agent in the clinical field is NK, in part because it is less expensive than other thrombolytic medicines. The objective of this study is to investigate the screening, isolation and characterization of the NK enzyme-producing Bacillus strain from fermented Soya beans. The sample of fermented soya beans were tested for the presence of fibrinolytic protease- producing bacteria, followed by the screening, extraction, characterization and clot lysis assays. A total of three isolates were screened for caseinolytic activities by casein hydrolysis assay. Out of those isolates, MRS18 was found to be potent in producing the enzyme proteinase. To determine the taxonomy and phylogeny of these isolates, biochemical and molecular characterization has been carried out. Bacillus amyloliquefaciens MRS18 has been found with the highest caseinolytic activity. The clot lysing ability of the potent strain Bacillus amyloliquefaciens was found to be 61.7% after 120 min, and on further purification, by ammonium sulphate precipitation method, the lysis percentage was found to be 656% after 120 min. From the results of the present study, we concluded that Bacillus amyloliquefaciens isolated from the fermented soya beans produced an NK enzyme that exhibits immense potential to lyse blood clots.

Effects of optically inert ions on up-conversion luminescence and temperature-sensing properties of Y2O2S: Er3+/Yb3+/Tm3+ phosphors

The quenching of luminescence in Er3+/Yb3+ co-doped with Tm3+ presents a dilemma as it substantially diminishes thermometric performance. In this study, Y2O2S: Er3+/Yb3+/Tm3+ phosphors were synthesized using a homogeneous precipitation method combined with a sulfurization process. In addition, three sets of fluorescence intensity ratio (FIR) models were designed, which have self-calibration function. The effects of incorporation of Li+ or Li+/Ba2+ on the up-conversion luminescence (UCL) intensity and thermometric performance of the phosphors were systematically studied. The results show that the introduction of Li+ or Li+/Ba2+ co-doping leads to lattice distortion and the formation of oxygen ion vacancies in the lattice, which further accelerates the energy transfer process and mixes the charge transfer states, and ultimately dramatically improves the UCL and thermometric performance. The introduction of Li+ and Li+/Ba2+ co-doping enhanced the UCL of the materials by about 3.7 times and 5.6 times compared to Y2O2S: Er3+/Yb3+/Tm3+. When based on nonthermally coupled levels (NTCLs), the Sr-max of Li+/Ba2+ co-doped sample is 0.080 K−1 at 573 K, which is 87 % higher than that based on TCLs. These findings not only provide a new avenue for improving the UCL and thermometric performance but also provide an accurate self-calibration FIR model over a wide temperature range.

Purification and characterization of recombinant human superoxide dismutase integrated with resilin-like polypeptide

Human superoxide dismutase (hSOD1) plays an important role in the aerobic metabolism and free radical eliminating process in the body. However, the production of existing SOD faces problems such as complex purification methods, high costs, and poor product stability. This experiment achieved low-cost, rapid, and simple purification of hSOD1 through ammonium sulfate precipitation method and heat resistance of recombinant protein. We constructed a recombinant protein hSOD1-LR containing a resilin-like polypeptide tag and expressed it. The interest protein was purified by ammonium sulfate precipitation method, and the results showed that the purification effect of 1.5 M (NH4)2SO4 was the best, with an enzyme activity recovery rate of 80 % after purification. Then, based on its thermal stability, further purification of the interest protein at 60 °C revealed a purification fold of up to 24 folds, and the purification effect was similar to that of hSOD1-6xHis purified by nickel column affinity chromatography. The stability of hSOD1-LR showed that the recombinant protein hSOD1-LR has better stability than hSOD-6xHis. hSOD1-LR can maintain 76.57 % activity even after 150 min of reaction at 70 °C. At same time, hSOD1-LR had activity close to 80 % at pH < 5, indicating good acid resistance. In addition, after 28 days of storage at 4 °C and 40 °C, hSOD1-LR retained 92 % and 87 % activity, respectively. Therefore, the method of purifying hSOD1-LR through salt precipitation may have positive implications for the study of SOD purification.

Examining the impact of nano‐sized Litharge, Tenorite, and Hematite on the thermal decomposition of ammonium perchlorate‐based cross‐linked composite modified double base propellant

AbstractThis study aims to compare the catalytic effects of three nano‐metal oxides (nMOs); Litharge (α‐PbO), Tenorite (CuO), and Hematite (α‐Fe2O3) on the thermal decomposition of an ammonium perchlorate based cross‐linked composite modified double base propellant (AP‐XLCMDBP). The three nMOs are synthesized via a chemical precipitation method and then characterized using XRD, FTIR, and SEM. Their effect on the thermal decomposition of AP‐XLCMDBP is studied using thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). The results indicate that Litharge has no significant effect on the thermal decomposition of AP‐XLCMDBP. However, both Tenorite and Hematite nanocatalysts accelerate the thermolysis process and enhance the total heat released from AP‐XLCMDBP. Moreover, compared to Tenorite, Hematite nanoparticles are found to be a more efficient catalyst, where their presence in AP‐XLCMDBP leads to a significant decrease in activation energies of the first and the second decomposition stages by 13.67 kJ/mol and 17.57 kJ/mol, respectively. An increase of the total decomposition heat by 153.73 J/g is also attained in the presence of Hematite, displaying its high catalytic action on the thermal decomposition of AP‐XLCMDBP.

Investigations on structure and optical properties of neutron irradiated nanocrystalline La2Zr2O7 pyrochlores

This research work investigates the response of nanocrystalline lanthanum zirconium oxide (LZO) under neutron irradiation, emphasizing grain size-dependent structural stability. LZO samples were synthesized with the chemical precipitation method and the LZO pellets were annealed at two different temperatures (1200 °C and 1400 °C) to obtain two different grain size samples, namely LZO-1200 and LZO-1400. The samples were exposed to neutrons at different doses (ranging from 1.63 × 1012 n/cm2 to 5.68 × 1014 n/cm2) and the effects were studied with X-ray diffraction, scanning electron microscopy, Raman scattering and optical characterization. The structural characterization results reveal that, the grain size and strain are significantly modified in LZO-1400 samples, and such changes are absent inLZO-1200 samples. The band gap and photoluminescence intensity are reduced significantly in LZO-1400 samples, however, this effect is not observed in LZO-1200 samples. The experimental results reveal that in LZO-1200 samples, the grain boundaries act as a sink for irradiation-induced defects and there is no significant change in the grain size, strain and band gap. However, in the case of the LZO-1400 sample, the grain size is larger than the cascades induced by primary knock-on atoms (PKAs) and it results in disorder-driven fast grain growth and changes in band gap and PL intensity. The LZO-1200 samples with small grain sizes are radiation resistant.

Synthesis of Mesoporous Silica from Palm Oil Boiler Ash (MS-POBA) with Addition of Methyl Ester Sulfonate as a Template for Free Fatty Acid Adsorption from Crude Palm Oil (CPO)

The synthesis of mesoporous material by utilizing palm oil boiler ash (POBA) waste as the silica source and methyl ester sulfonate (MES) surfactant as the template for a high-porosity was investigated for free fatty acids (FFA) adsorption. The research was initiated with silica extraction from POBA by sodium hydroxide addition through the sol-gel precipitation method. Silica modification was carried out with MES surfactant and 3-aminopropyltrimethoxysilane (APTMS) as the co-structure-directing agent (CSDA) in different calcination temperatures. Mesoporous silica-POBA (MS-POBA) free template had a surface area, pore diameter, and pore volume (41.033 m2/g, 4.180 nm, and 0.250 cm3/g) lower than MS-POBA with the template (71.0147 m2/g, 7.923 nm, and 0.524 cm3/g). The ability of MS-POBA to adsorb FFA reached its optimum conditions with an adsorption time of 20 min and an adsorbent dosage of 0.24 g. The FFA removal by MS-POBA with the template was found to have higher adsorption ability, which was 35.54%, compared to the MS-POBA free template of 26.68%. The high porosity of MS-POBA with a template makes the FFA adsorption capacity of this material higher than MS-POBA free template.

Comprehensive recovery of valuable elements from vanadium precipitation liquor using selective impurity removal-reduction precipitation process

The vanadium precipitation liquor produced by the vanadium slag extraction process contains various valuable elements, which are not utilized at high value. In this paper, chromium is recovered through aluminum salt impurity removal - chemical reduction precipitation method. Moreover, the ammonia nitrogen and sodium sulfur in the vanadium precipitation liquor are recovered by stripping and crystallization, thereby achieving comprehensive resource recovery and utilization. The aluminum salt slag removal reduction chemical precipitation method is used to separate Cr from Si, Ca and V impurities. As a result, the obtained Cr2O3 product has a purity of 98.20%, the chromium recovery efficiency is 97.58%, and the silicon removal efficiency reaches 99.66%. The ammonia nitrogen was recovered by stripping, which would be reused to the vanadium precipitation process, with an ammonia nitrogen stripping efficiency of 98%. The purity of NH4Cl is 99.13% and meets the 99-level national standard. The Na2SO4 was recovered by evaporation concentration - crystallization method, which would be reused to the vanadium slag roasting process, with a Na2SO4 recovery efficiency of 88.38%. And the purity of Na2SO4 is 98.85%, which meets the industrial standard for Class II Na2SO4 products. The final solution after comprehensive recovery of valuable elements would be reused to the leaching process, thereby achieving water circulation. This process realizes the high-value utilization of chromium, ammonia, nitrogen, sodium and sulfur, and has no wastewater discharge and is an environment-friendly route.

An efficient approach for preparation of battery-grade Li2CO3 from intermediate product Li2SiO3

The continuous development of lithium-ion batteries (LIBs) manufacturing industry calls for the mass production of Li2CO3, which serves as a pivotal raw material for LIBs. In our previous study, Li was successfully precipitated as intermediate product Li2SiO3 from an alkaline solution containing Si by the hydrothermal precipitation method, realizing the preliminary separation of Li and impurities. In this research, H2SO4 digestion-water leaching-Na2CO3 precipitation process was proposed to manufacture Li2CO3 from the intermediate product Li2SiO3. Firstly, the reaction feasibility of H2SO4 digestion-water leaching and direct H2SO4 leaching for Li2SiO3 were comparatively evaluated through thermodynamic calculation and experimental research. Compared to direct H2SO4 leaching, H2SO4 digestion-water leaching process is preferred in view of its excellent filtration properties. Subsequently, systematic digestion and leaching experiments showed that up to 97.1 % of Li was extracted under the optimized conditions, and the concentration of Li in the leach liquor is as high as 29.33 g/L. After pH adjustment and Al removal, Na2CO3 precipitation were adopted for Li2CO3 production. The equilibrium relationship in Li2SO4-Na2CO3-H2O system was analyzed to predict the precipitation behavior of Li and select appropriate operation window for Li2CO3 preparation. Finally, with an additional carbonation-decomposition process, a Li2CO3 product with a purity of 99.51 % is produced. This process realizes efficient synthesis of battery-grade Li2CO3 from the intermediate product Li2SiO3.

Effects of Helianthus annuus seeds on antioxidants, lipid profile and serum urea and creatinine in obesity induced rats using high fat diet

High-fat diets have been strongly associated with common metabolic diseases. Clinical practices often link these diseases, such as hyperlipidemia and oxidative stress resulting from the accumulation of reactive oxygen species, to severe conditions like cancer, diabetes, atherosclerosis, and cardiovascular diseases. Managing these conditions is often financially demanding. Helianthus annuus seeds, known to be non-toxic even at doses greater than 5000mg/kg in rats, with an LD50 greater than 5000mg/kg, has demonstrated efficacy in reducing elevated blood sugar levels and BMI in both animal and human studies. Therefore, further research is needed to explore the potential effects of sunflower seeds on antioxidants, lipid profiles, and serum urea and creatinine levels in rats induced with obesity using a high-fat diet. In this study, overnight fasting blood samples were collected to conduct lipid profile tests (HDL, LDL, VLDL, and triglycerides). These tests utilized a photometric system with procedures derived from the Diasys-G Emmany kit and the measurement and precipitation method. The modified Jaffe technique for in-vitro measurement of creatinine in serum was employed to measure urea and creatinine levels. The experiment involved 27 Wistar rats weighing between 350 and 400 grams, randomly divided into 9 groups, with 3 rats in each group. Group 1 served as the control, while groups 2 to 9 were subjected to various conditions: high-fat diets alone for 6 weeks (group 2), high-fat diets with high (5000mg/kg body weight), medium (3000 mg/kg body weight), or low (2000 mg / kg body weight) doses of Helianthus annuus seeds powder for 6 weeks (groups 3, 4, and 5, respectively). Additionally, there were variations in duration and doses in groups 6 to 9, where rats were fed high-fat diets 20 g/ kg / day /rats for 5 weeks and then supplemented with Helianthus annuus seeds powder (5000 mg / kg, 3000 mg / kg and 2000 mg / kg per rat for group 6,7,8 or Metformin 70 mg / kg per rat for group 9) for 1 week. The results revealed a significant (P &lt; 0.05) increase in serum cholesterol, triglyceride, and low-density lipoprotein (LDL) levels in rats across all groups compared to the control. However, all groups supplemented with Helianthus annuus seeds alongside high-fat diets displayed a significantly increased HDL level (P &lt; 0.05) compared to rats fed only high-fat diet alone. Creatinine levels were significantly increased in all Helianthus annuus seeds -supplemented groups compared to the high-fat diet alone, while urea levels showed no significant differences among the groups. Furthermore, rats in all Helianthus annuus seeds -supplemented groups alongside high-fat diets demonstrated a significantly increased glutathione reductase activity (P &lt; 0.05) compared to the control and high-fat diet alone. The study indicated that sunflower seeds significantly bolster antioxidant protection, elevate HDL levels, and increase creatinine levels in rats fed high-fat diets, suggesting potential beneficial effects in mitigating the adverse impacts of high-fat diets on health parameters.

Effect of Citrate on Morphological and Structural Properties of Hydroxyapatite Nanoparticles Synthesized by Wet Chemical Precipitation Method

Effect of Citrate on Morphological and Structural Properties of Hydroxyapatite Nanoparticles Synthesized by Wet Chemical Precipitation Method

Synthesis and Characterization of Copper(II) Oxide (CuO-NP) Nanoparticles using Chemical Precipitation Method

Synthesis and Characterization of Copper(II) Oxide (CuO-NP) Nanoparticles using Chemical Precipitation Method

Sustainable multi-functional additives: Zinc soaps from vegetable oil and fatty acids in natural rubber compounds

Zinc soaps derived from various vegetable oils and fatty acids were synthesized, and the product with the highest yield was chosen for compounding with silica-filled natural rubber (NR). Specifically, zinc soaps of coconut oil and palm oil, with yields of 72% and 73%, respectively, were prepared through precipitation and metathesis methods. Additionally, zinc soaps from palm fatty acid distillate (PFAD) and stearic acid, both with a yield of 70%, were synthesized using modified fusion and precipitation methods, respectively. Subsequently, these zinc soaps were incorporated into silica-filled NR compounds and compared with the commercial dispersing aid, Ultra flow 700 s. The results indicated that the zinc soaps played a significant role in plasticizing and lubricating the rubber compounds, as evidenced by reductions in Mooney viscosity, Mooney relaxation rate, and minimum torque (ML). Furthermore, the zinc soaps influenced curing properties by accelerating the cure process, as reflected in decreased cure time (tc90) and increased cure rate and torque difference compared to compounds without processing aid. Moreover, NR compounded with zinc soap exhibited superior mechanical properties, including higher tensile strength, elongation at break, tear strength, and hardness.

Green production of functionalized few-layer borophene decorated with cerium-doped iron oxide nanoparticles for repeatable hydrogen peroxide detection

Functionalized few-layer borophene (FFB) was prepared using gallnut extract and coffee waste extract as natural exfoliating and stabilizing agents in an environmentally friendly ultrasonic and high shear exfoliation. Here, a facile precipitation method was employed to grow iron oxide nanoparticles doped with cerium (Ce-FeONPs) onto the surface of FFB. This intriguing combination of materials yielded Ce-FeONPs nanoparticles that exhibited exceptional peroxidase-like activity, efficiently catalyzing the conversion of 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue oxidized TMB (oxTMB) in the presence of hydrogen peroxide (H2O2). Additionally, the introduction of FFB contributes a reducibility effect to the catalytic oxidation of TMB, facilitating the restoration of the oxTMB to TMB. Thus, FFB-Ce-FeONPs showcase intriguing properties encompassing both oxidative and reductive characteristics, suggesting their potential as a reagent for repeated detection of H2O2. Moreover, a colorimetric sensing system enabled the liner detection of H2O2 spanning a concentration range from 0.08 to 1 mM, with a detection limit of 0.03 mM. Noteworthily, FFB-Ce-FeONPs demonstrated sustained efficacy over ten successive recycling cycles, as indicated by consistent slopes and observable color changes. In summary, this work reports the first application of nanoenzymes in repetitive H2O2 detection. Even after ten multiple cycles, the detection limit remains virtually unaltered, underscoring the robustness and enduring effectiveness of the engineered nanomaterial. The proposed simultaneous oxidation and reduction strategies for detecting H2O2 showed a commendable capability in ten cycles of H2O2 detection, thus providing a promising approach in the field of H2O2 detection.

MnO2 nanosheets based catechol oxidase mimics for robust electrochemical sensor: Synthesis, mechanism and its application for ultrasensitive and selective detection of dopamine

Nanozymes have favorable activity and good stability, which are potential alternatives to natural enzymes and widely applied in biosensing. However, nanozymes based electrochemical sensors are fewer, because many nanozymes are not easy to form efficient electrocatalytic interface and experience interference from the possible oxidizable species. Herein, ultrathin MnO2 nanosheets (MnO2 NSs) were synthesized by reduction of KMnO4 in acidic environment by chemical precipitation method. The MnO2 NSs show excellent catechol oxidase mimicking activity. The steady-state kinetics of MnO2 NSs shows a higher Vmax of 3.441 µM s−1. Additionally, the catalytic mechanism is that in the presence of oxygen, catechol or its analogues are oxidized to quinone or quinoids, while oxygen is reduced to H2O. Afterwards, the possible mechanism of dopamine (DA) at MnO2 NSs-modified electrode is investigated. DA is first catalytically oxidized to dopamine quinone (DQ) by MnO2 NSs based catechol oxidase, which further undergoes irreversible electrochemical reduction to DA involving two protons and two electrons transfer during the process. On the basis of this, a selective and ultrasensitive amperometric detection of DA at 0.0 V (vs. SCE) was explored, which have two linear parts, 0.01–20 μM and 20–100 μM DA with the LOD of 4.1 nM (S/N = 3). Most importantly, the presence of oxidizable species including ascorbic acid, uric acid and cysteine may coexist with DA in biological systems do not exhibit any appreciable interference. The as-proposed method was applicable to detect DA in human serum samples with good satisfactory accuracy and recovery. This research casts prospect to apply nanozymes for electrochemical sensor with excellent analytical performance.

Synthesis of flower-like ZnO nanoparticles for label-free point of care detection of carcinoembryonic antigen

In this work, flower-like ZnO nanoparticles (ZnONPs) were synthesized using zinc nitrate (Zn(NO3)2 6H2O) as a precursor with KOH. The morphology of the ZnONPs was controlled by varying the synthesis temperature at 50, 75 and 95 °C. The morphology and structure of ZnONPs were characterized using Scanning Electron Microscopy, and X-Ray Diffraction and Brunauer-Emmett Teller analysis. ZnONPs were successfully synthesized by a simple chemical precipitation method. A synthesis temperature of 75 °C produced the most suitable flower-like ZnONPs, which were combined with graphene nanoplatelets to develop a label-free electrochemical immunosensor for the detection of the colon cancer biomarker carcinoembryonic antigen in human serum. Under optimum conditions, the developed immunosensor showed a linear range of 0.5–10.0 ng mL−1 with a limit of detection of 0.44 ng mL−1. The label-free electrochemical immunosensor exhibited good selectivity, reproducibility, and repeatability, and recoveries were excellent. The immunosensor is used with a Near-Field Communication potentiostat connected to a smartphone to facilitate point-of-care cancer detection in low-resource locations.

Photocatalytic assisted chemical mechanical polishing for silicon carbide using developed ceria coated diamond core-shell abrasives

The practical application of current photocatalytic-assisted chemical mechanical polishing (PCMP) technology still faces some challenges and difficulties, such as complex preparation process of abrasives, chemical failure, and the use of toxic chemicals. Herein, novel CeO2-coated diamond core/shell structure abrasives were successfully synthesized using a chemical precipitation method and applied in SiC-PCMP. After coating CeO2 on the surface of the diamond, the materials removal rate (MRR) was 56 % higher than that of the diamond abrasives. With ultraviolet (UV) irradiation, the MRR of CeO2/diamond abrasives (11.5 nm/min) increased by about 195 % compared with CeO2/diamond composite abrasives without UV. High surface quality (Ra: 0.4 nm) of the SiC substrate was obtained under UV light irradiation. The materials removal mechanism of SiC-PCMP was proposed.

Core-Double-Shell TiO2@Fe3O4@C Microspheres with Enhanced Cycling Performance as Anode Materials for Lithium-Ion Batteries.

Due to the volume expansion effect during charge and discharge processes, the application of transition metal oxide anode materials in lithium-ion batteries is limited. Composite materials and carbon coating are often considered feasible improvement methods. In this study, three types of TiO2@Fe3O4@C microspheres with a core-double-shell structure, namely TFCS (TiO2@Fe3O4@C with 0.0119 g PVP), TFCM (TiO2@Fe3O4@C with 0.0238 g PVP), and TFCL (TiO2@Fe3O4@C with 0.0476 g PVP), were prepared using PVP (polyvinylpyrrolidone) as the carbon source through homogeneous precipitation and high-temperature carbonization methods. After 500 cycles at a current density of 2 C, the specific capacities of these three microspheres are all higher than that of TiO2@Fe2O3 with significantly improved cycling stability. Among them, TFCM exhibits the highest specific capacity of 328.3 mAh·g-1, which was attributed to the amorphous carbon layer effectively mitigating the capacity decay caused by the volume expansion of iron oxide during charge and discharge processes. Additionally, the carbon coating layer enhances the electrical conductivity of the TiO2@Fe3O4@C materials, thereby improving their rate performance. Within the range of 100 to 1600 mA·g-1, the capacity retention rates for TiO2@Fe2O3, TFCS, TFCM, and TFCL are 27.2%, 35.2%, 35.9%, and 36.9%, respectively. This study provides insights into the development of new lithium-ion battery anode materials based on Ti and Fe oxides with the abundance and environmental friendliness of iron, titanium, and carbon resources in TiO2@Fe3O4@C microsphere anode materials, making this strategy potentially applicable.

Fe-doping induced textural and morphological evolution of MnO2 and its enhanced performance for o-xylene complete oxidation

Fe-MnO2 nanocomposite was prepared via a redox–precipitation method combined with a subsequent aging treatment at low-temperature. Various characterizations showed that Fe was incorporated into MnO2 lattice that changed the relative intensity of MnO2 crystal planes. Thus, the structural defect was formed and the anisotropic growth of the MnO2 crystallite phase was suppressed. As a result, the morphology of MnO2 was transformed from nanowires to nanoparticles. In addition, the catalytic property of Fe-MnO2 was significantly enhanced than that of pristine MnO2 for the complete oxidation of o-xylene. This work provides a simple and effective strategy for regulating MnO2 texture and activity.

Glass-sulfur composite cathodes: A new strategy for improving the performance of lithium-sulfur batteries

In this study, we investigated the potential of glass-sulfur composites to improve lithium–sulfur battery (LSB) performance. Glass-sulfur composites were prepared by the precipitation method, and the effect of varying carbon black content was studied. The results showed that glass addition improved the battery performance due to the high ion-conductivity of its structural motif. The 75 % glass variant demonstrated the best results, in both the low carbon and high carbon cases. The cyclic voltammetry (CV) and electrical impedance spectroscopy (EIS) measurements showed that glass-sulfur composites had lower resistivity than pure sulfur, which was beneficial for battery performance. The XANES analysis revealed that the incorporated glass interacted with and modified the properties of sulfur, leading to a higher proportion of sulfur in the -1 oxidation state (S−1). This suggests that the high proportion of S−1 phase benefitted battery capacity. Overall, glass-sulfur composites prepared using the precipitation method and incorporating a high content of carbon show promise as a novel and improved cathode material for LSBs.