An integrated electrode based on nanoflakes of MoS2 on carbon cloth for enhanced lithium storage

Due to its high specific capacity (in theory), molybdenum disulfide (MoS₂) has been recognized as a plausible substitute in lithium-ion batteries (LIBs). However, it suffers from an inferior electric conductivity and a substantial volume change during Li⁺ insertion/extraction. By using a facile hydrothermal method, a flexible free-standing MoS₂ electrode has here been fabricated onto a carbon cloth substrate. The grafting of ultrathin MoS₂ nanoflakes onto the carbon cloth framework (forming CC@MoS₂), was shown to facilitate an improved electron transport, as well as an enhanced Li⁺ transport. As expected, the as-obtained CC@MoS₂ electrode was observed to exhibit an excellent lithium storage performance. It delivers a high discharge specific capacity of 2.42 mA h cm⁻² at 0.7 mA cm⁻² (even after 100 cycles), which is an impressive result.

Integrated carbon cloth@MoS₂ electrode is fabricated via a facile hydrothermal method as a binder-free anode for lithium-ion batteries.     

MoS2/carbon composites prepared by ball-milling and pyrolysis for the high-rate and stable anode of lithium ion capacitors

Lithium ion capacitors (LICs), bridging the advantages of batteries and electrochemical capacitors, are regarded as one of the most promising energy storage devices. Nevertheless, it is always limited by the anodes that accompany with low capacity and poor rate performance. Here, we develop a versatile and scalable method including ball-milling and pyrolysis to synthesize exfoliated MoS₂ supported by N-doped carbon matrix derived from chitosan, which is encapsulated by pitch-derived carbon shells (MoS₂/CP). Because the carbon matrix with high nitrogen content can improve the electron conductivity, the robust carbon shells can suppress the volume expansion during cycles, and the sufficient exfoliation of lamellar MoS₂ can reduce the ions transfer paths, the MoS₂/CP electrode delivers high specific capacity (530 mA h g⁻¹ at 100 mA g⁻¹), remarkable rate capability (230 mA h g⁻¹ at 10 A g⁻¹) and superior cycle performance (73% retention after 250 cycles). Thereby, the LICs, composed of MoS₂/CP as the anode and commercial activated carbon (21 KS) as the cathode, exhibit high power density of 35.81 kW kg⁻¹ at 19.86 W h kg⁻¹ and high energy density of 87.74 W h kg⁻¹ at 0.253 kW kg⁻¹.

MoS₂/carbon composites prepared by ball-milling and pyrolysis for the high-rate anode of lithium ion capacitors.     

Self-healing solid polymer electrolyte based on imine bonds for high safety and stable lithium metal batteries

Due to their low flammability, good dimensional stability and chemical stability, solid polymer electrolytes are currently attracting extensive interest for building lithium metal batteries. But severe safety issues such as cracks or breakage, resulting in short circuits will prevent their widespread application. Here, we report a new design of self-healing solid polymer electrolyte (ShSPE) based on imine bonds, fabricated from varying amounts of polyoxyethylenebis(amine) and terephthalaldehyde through a simple Schiff base reaction. Moreover, adding diglycidyl ether of bisphenol A improves the flexibility and high stretchability of the polymer electrolyte. The polymer networks exhibit good thermal stability and excellent self-healing characteristics. The ShSPE with the highest NH₂–PEG–NH₂ content (ShSPE-3) has an improved lithium ion transference number of 0.39, and exhibits an electrochemical stability up to 4.5 V vs. Li/Li⁺. ShSPE-3 shows the highest ionic conductivity of 1.67 × 10⁻⁴ S cm⁻¹ at 60 °C. Besides, the interfacial stability of ShSPE-3 is promoted and the electrolyte membrane exhibits good cycling performance with LiFePO₄, and the LiFePO₄/Li cell exhibits an initial discharge capacity of 141.3 mA h g ⁻¹. These results suggest that self-healing solid polymer electrolytes are promising candidates for high safety and stable lithium metal batteries.

A self-healing solid polymer electrolyte based on imine bonds is fabricated through a simple Schiff base reaction. The polymer electrolyte exhibit excellent self-healing characteristics and good electrochemical performance.     

Iron encapsulated in single-walled carbon nanotubes for obtaining the evidence of improved coulombic efficiency and improving the lithium battery performance of ZnO anodes

Cycling coulombic efficiency including the 1^st cycle is a crucial factor for nano-carbon based anodes. How to improve their coulombic efficiency and further prove whether the additional reversible capacity produced from the SEI film in the 1^st cycle is an obstacle for their possible commercial application in Li ion batteries (LIBs). For this aim, a novel composite of Fe-encapsulated single-walled carbon nanotubes (Fe@SWNTs) with special nano-structure was designed and used as an anode material for LIBs. The resulting Fe@SWNT anode can provide much larger coulombic efficiency of 53.1% in the 1^st cycle than 35.6% for pure SWNTs, implying the value increment reached ∼50%. The Fe@SWNTs can exhibit an reversible capacity of 420 mA h g⁻¹ after 300 cycles and excellent rate performance at room temperature, being obviously better than 275 mA h g⁻¹ for a SWNT anode. The origination of this extra improved reversible capacity can be confirmed to be derived from the reversible reaction of SEI film activated by the Fe catalyst. Meanwhile, the Fe@SWNT anodes exhibited superior low-temperature (at 5 and −15 °C) electrochemical performance, which should be associated with an improved effect of the highly conducting Fe at low temperature, and with the activation of catalyst Fe on the reversible capacity. In addition, when Fe@SWNTs were developed as carriers for attaching ZnO, the ZnO/Fe@SWNTs can deliver much better LIB performance than anodes of pure ZnO and ZnO/SWNTs. Thus, catalyst modification supplied a promising route to obtain improved coulombic efficiency and reversible capacity for LIB nano-carbon based anodes.

Fe filler enables catalytic activation for the anode to obtain improved lithium battery performance.     

MoS2-assisted Fe2+/peroxymonosulfate oxidation for the abatement of phenacetin: efficiency,mechanisms and toxicity evaluation

In this study, molybdenum disulfide (MoS₂) was chosen as a co-catalyst to enhance the removal efficiency of phenacetin (PNT) in water by a ferrous ion-activated peroxymonosulfate (Fe²⁺/PMS) process. Operating parameters, such as the initial solution pH and chemical dose on PNT degradation efficiency were investigated and optimized. Under an initial pH of 3, an Fe²⁺ dose of 25 μM, a PMS dose of 125 μM and a MoS₂ dose of 0.1 g L⁻¹, the degradation efficiency of PNT reached 94.3%, within 15 min. The presence of common water constituents including Cl⁻, HCO₃⁻, SO₄²⁻ and natural organic matter (NOM) will inhibit degradation of PNT in the MoS₂/Fe²⁺/PMS system. Radical quenching tests combined with electron paramagnetic resonance (EPR) results indicated that in addition to free radical species (˙OH, SO₄˙⁻ and O₂˙⁻), nonradical reactive species (¹O₂) were also crucial for PNT degradation. The variations in the composition and crystalline structure of the MoS₂ before and after the reaction were characterized by XPS and XRD. Further, the degradation pathways of PNT were proposed according to the combined results of LC/TOF/MS and DFT calculations, and primarily included hydroxylation of the aromatic ring, cleavage of the C–N bond of the acetyl-amino group, and cleavage of the C–O bond of the ethoxy group. Finally, toxicity assessment of PNT and its products was predicted using the ECOSAR program.

Performance, mechanisms and toxicity evaluation of PNT degradation by the MoS₂/Fe²⁺/PMS system were investigated.     

Design and synthesis of hierarchical NiO/Ni3V2O8 nanoplatelet arrays with enhanced lithium storage properties

Hierarchical NiO/Ni₃V₂O₈ nanoplatelet arrays (NPAs) grown on Ti foil were prepared as free-standing anodes for Li-ion batteries (LIBs) via a simple one-step hydrothermal approach followed by thermal treatment to enhance Li storage performance. Compared to the bare NiO, the fabricated NiO/Ni₃V₂O₈ NPAs exhibited significantly enhanced electrochemical performances with superior discharge capacity (1169.3 mA h g⁻¹ at 200 mA g⁻¹), excellent cycling stability (570.1 mA h g⁻¹ after 600 cycles at current density of 1000 mA g⁻¹) and remarkable rate capability (427.5 mA h g⁻¹ even at rate of 8000 mA g⁻¹). The excellent electrochemical performances of the NiO/Ni₃V₂O₈ NPAs were mainly attributed to their unique composition and hierarchical structural features, which not only could offer fast Li⁺ diffusion, high surface area and good electrolyte penetration, but also could withstand the volume change. The ex situ XRD analysis revealed that the charge/discharge mechanism of the NiO/Ni₃V₂O₈ NPAs included conversion and intercalation reaction. Such NiO/Ni₃V₂O₈ NPAs manifest great potential as anode materials for LIBs with the advantages of a facile, low-cost approach and outstanding electrochemical performances.

Hierarchical NiO/Ni₃V₂O₈ nanoplatelet arrays (NPAs) grown on Ti foil were prepared as free-standing anodes for Li-ion batteries (LIBs) via a simple one-step hydrothermal approach followed by thermal treatment to enhance Li storage performance.     

One-pot synthesis of CoFe2O4/rGO hybrid hydrogels with 3D networks for high capacity electrochemical energy storage devices

CoFe₂O₄/reduced graphene oxide (CoFe₂O₄/rGO) hydrogel was synthesized in situ via a facile one-pot solvothermal approach. The three-dimensional (3D) network structure consists of well-dispersed CoFe₂O₄ nanoparticles on the surfaces of graphene sheets. As a binder-free electrode material for supercapacitors, the electrochemical properties of the CoFe₂O₄/rGO hybrid hydrogel can be easily adjusted by changing the concentration of the graphene oxide (GO) precursor solution. The results indicate that the hybrid material made using 3.5 mg mL⁻¹ GO solution exhibits an outstanding specific capacitance of 356 F g⁻¹ at 0.5 A g⁻¹, 68% higher than the pure CoFe₂O₄ counterpart (111 F g⁻¹ at 0.5 A g⁻¹), owing to the large specific surface area and good electric conductivity. Additionally, an electrochemical energy storage device based on CoFe₂O₄/rGO and rGO was assembled, which exhibits a high energy density of 17.84 W h kg⁻¹ at a power density of 650 W kg⁻¹ and an excellent cycling stability with 87% capacitance retention at 5 A g⁻¹ after 4000 cycles. This work takes one step further towards the development of 3D hybrid hydrogel supercapacitors and highlights their potential application in energy storage devices.

CoFe₂O₄/reduced graphene oxide (CoFe₂O₄/rGO) hydrogel was synthesized in situ via a facile one-pot solvothermal approach.     

Tuning the photocatalytic/electrocatalytic properties of MoS2/MoSe2 heterostructures by varying the weight ratios for enhanced wastewater treatment and hydrogen production

Two-dimensional (2D) heterojunctions with layered structures give high flexibility in varying their photocatalytic/electrocatalytic properties. Herein, 2D/2D heterostructures of MoS₂/MoSe₂ with different weight-ratios (1 : 1, 1 : 3, and 3 : 1) have been prepared by a simple one-step microwave-assisted technique. The characterization studies confirm formation of crystalline MoS₂/MoSe₂ nanoparticles with a high surface area (60 m² g⁻¹) and porous structure. The high synergistic-effect (1.73) and narrow bandgap (∼1.89 eV) of the composites result in enhanced photo-degradation efficiency towards methylene blue dye (94%) and fipronil pesticide (80%) with high rate constants (0.33 min⁻¹ and 0.016 min⁻¹ respectively) under visible light. The effect of pH, catalyst dose, and illumination area on photodegradation has been optimized. Photodegradation of real-industrial wastewater shows 65% COD and 51.5% TOC removal. Trapping experiments confirm that holes are mainly responsible for degradation. The composites were highly reusable showing 75% degradation after 5-cycles. MoS₂/MoSe₂ composites show excellent electrochemical water-splitting efficacy through hydrogen-evolution-reaction (HER) exhibiting a stable high current density of −19.4 mA cm⁻² after 2500 cyclic-voltammetry (CV) cycles. The CV-plots reveal high capacitance activity (C_dl value ∼607 μF cm⁻²) with a great % capacitance retention (>90%). The as-prepared 2D/2D-catalysts are highly active in sunlight and beneficial for long-time physico-chemical wastewater treatment. Moreover, the electrochemical studies confirm that these composites are potential materials for HER activity and energy-storage applications.

The 2D/2D-MoS₂/MoSe₂ catalysts with good photocatalytic/electrocatalytic properties can be potential materials for wastewater treatment and hydrogen production.     

Construction of magnetic MgFe2O4/CdS/MoS2 ternary nanocomposite supported on NaY zeolite and highly efficient sonocatalytic degradation of organic pollutants

In this work, the novel magnetically separable NaY zeolite/MgFe₂O₄/CdS nanorods/MoS₂ nanoflowers nanocomposite was successfully synthesized through the ultrasonic-assisted solvothermal approach. FESEM, EDAX, XRD, FTIR, TEM, AFM, VSM, N₂-BET, UV-vis DRS and PL were utilized to identify the as-synthesized nanocomposite. Subsequently, the sonocatalytic activity of this nanocomposite was assessed in the degradation of organic dyes, including methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) from water solutions for the first time. Several analytical parameters like irradiation time, process type, initial MB concentration, H₂O₂ concentration, catalyst dosage, organic dye type, and US power have been systematically investigated to attain the maximum sonocatalytic yield. Regarding the acquired data, the NaY/MgFe₂O₄/CdS NRs/MoS₂ NFs sonocatalyst was incredibly able to completely eliminate the MB via engaging the US/H₂O₂ system. The kinetic evaluates demonstrated the sonodegradation reactions of the MB followed a first-order model. The apparent rate constant (k_app) and half-life time (t_1/2) acquired for the sonodegradation process of MB utilizing the US/H₂O₂/NaY/MgFe₂O₄/CdS NRs/MoS₂ NFs system were measured to be 1.162 min and 0.596 min⁻¹, respectively. The free ˙OH radicals were also recognized as the main reactive oxygen species in the MB sonodegradation process under US irradiation. In addition, the outcomes of the recyclability study of the NaY/MgFe₂O₄/CdS NRs/MoS₂ NFs sonocatalytic clearly displayed a less than 6% drop of the catalytic activity in up to four sequential runs. Lastly, a plausible mechanism for the sonodegradation reaction of organic dyes was suggested and discussed.

A magnetically separable NaY zeolite/MgFe₂O₄/CdS NRs/MoS₂ NFs nanocomposite was successfully manufactured and utilized as a new sonocatalyst for the effective degradation of toxic organic dyes.     

A comparative study on the photocatalytic degradation of organic dyes using hybridized 1T/2H, 1T/3R and 2H MoS2 nano-sheets

MoS₂ is a very attractive material and has been well studied for potential applications in various areas. However, due to the wide variety of factors affecting the molecular and electronic structure of MoS₂, several contradictory reports about the adsorptive and photocatalytic properties of such materials have been published. In most of these reports, the effect of the actual phase of the materials on the properties was neglected. Here, different phases of MoS₂ nanosheets (1T/2H, 1T/3R and 2H) have been obtained using the hydrothermal method with different Mo : S molar ratios and different autoclave filling ratios. The obtained materials have been thoroughly characterized using Raman, UV-vis, powder XRD, SEM, TEM and XPS measurements in order to accurately identify the existing phases in each material. A comparative study of the photocatalytic organic dye degradation efficiency under white light irradiation has been conducted using methyl orange to correlate the different activity of each material to the respective phase composition. The results indicate a much higher performance of the 1T/2H phase compared to the 2H and 3R phases. Detailed computational studies of the different phases revealed the emergence of mid-gap states upon introducing 1T sites into the 2H lattice. This leads to the improvement of the photocatalytic activity of 1T/2H compared to the other prepared materials.

MoS₂ is a very attractive material and has been well studied for potential applications in various areas.     

Single-walled carbon nanotubes/lithium borohydride composites for hydrogen storage: role of in situ formed LiB(OH)4, Li2CO3 and LiBO2 by oxidation and nitrogen annealing

Lithium Borohydride (LiBH₄), from the family of complex hydrides has received much attention as a potential hydrogen storage material due to its high hydrogen energy densities in terms of weight (18.5 wt%) and volume (121 kg H₂ per mol). However, utilization of LiBH₄ as a hydrogen carrier in off- or on-board applications is hindered by its unfavorable thermodynamics and low stability in air. In this study, we have synthesized an air stable SWCNT@LiBH₄ composite using a facile ultrasonication assisted impregnation method followed by oxidation at 300 °C under ambient conditions (SWLiB-A). Further, part of the oxidized sample is treated at 500 °C under nitrogen atmosphere (SWLiB-N). Upon oxidation in air, the in situ formation of lithium borate hydroxide (LiB(OH)₄) and lithium carbonate (Li₂CO₃) on the surface of the composite (SWLiB@LiBH₄) is observed. But in the case of SWLiB-N, the surface hydroxyl groups [OH₄]⁻ completely vanished leaving porous LiBH₄ with SWCNT, LiBO₂ and Li₂CO₃ phases. Hydrogen adsorption/desorption experiments carried out at 100 °C under 5 bar H₂ pressure showed the highest hydrogen adsorption capacity of 4.0 wt% for SWLiB-A and 4.3 wt% for SWLiB-N composites in the desorption temperature range of 153–368 °C and 108–433 °C respectively. The observed storage capacity of SWLiB-A is due to the H⁺ and H⁻ coupling between in situ formed Li⁺[B(OH)₄]⁻, Li²⁺[CO₃]⁻ and Li⁺[BH₄]⁻. Whereas in SWLiB-N, the presence of positively charged Li and B atoms and LiBO₂ acts as a catalyst which resulted in reduced de-hydrogenation temperature (108 °C) as compared to bulk LiBH₄. Moreover, it is inferred that the formation of intermediate phases such as Li⁺[B(OH)₄]⁻, Li²⁺[CO₃]⁻ (SWLiB-A) and Li⁺[BO₂]⁻ (SWLiB-N) on the surface of the composites not only stabilizes the composite under ambient conditions but also resulted in enhanced de- and re-hydrogenation kinetics through catalytic effects. Further, these intermediates also act as a barrier for the loss of boron and lithium through diborane release from the composites upon dehydrogenation. Furthermore, the role of in situ formed intermediates such as LiB(OH)₄, Li₂CO₃ and LiBO₂ on the stability of the composite under ambient conditions and the hydrogen storage properties of the SWCNT@LiBH₄ composite are reported for the first time.

In situ formed Li⁺[B(OH)₄]⁻, Li²⁺[CO₃]⁻ & Li⁺[BO₂]⁻ on the surface of SWCNT@LiBH₄ not only stabilizes the composites in ambient conditions but also enhanced the de- and re-hydrogenation kinetics of the composites through catalytic effect.     

Effect of Fe,Co and Ni promoters on MoS2 based catalysts for chemoselective hydrogenation of nitroarenes

The effect of Fe, Co and Ni promoters on supported MoS₂ catalysts for hydrogenation of nitroarenes were systematically investigated via experiment, characterization and DFT calculation. It was found that the addition of promoters remarkably improved the reaction activity in a sequence of Ni > Co > Fe > Mo. Meanwhile Ni promoted catalyst with the best performance showed good recyclability and chemoselectivity for a wide substrate scope. The characterization results revealed that the addition of promoters decreased the interaction between Mo and support and facilitated the reductive sulfidation of Mo species to produce more coordinated unsaturated sites (CUS). DFT calculations showed that the addition of promoters increased the formation of CUS, and enhanced the adsorption of hydrogen. The influence degree of promoters followed the sequence Ni > Co > Fe > Mo, which was consistent with those of the activities. Nitrobenzene hydrogenation and hydrogen activation occurred at the S and Mo edge, respectively. The adsorbed hydrogen diffused from the Mo edge to the S edge to participate in the hydrogenation reaction. Mechanism investigation showed that the main reason for increased activity by the addition of promoters was the increase of amounts of CUS and the secondary reason was the augmentation of intrinsic activity of CUS. The present studies give a new understanding for promoter modified MoS₂ catalysts applied for hydrogenation of nitroarenes.

The addition of promoters remarkably improved the activity for hydrogenation of nitroarenes in a sequence of Ni > Co > Fe > Mo and the amount of CUS active center was supposed to be the main reason to influence the reaction activity.     

A simple electrochemical sensor based on rGO/MoS2/CS modified GCE for highly sensitive detection of Pb(ii) in tobacco leaves

High-performance electrode modification materials play a crucial role in improving the sensitivity of sensor detection in electrochemical determination of heavy metals. In this study, a rGO/MoS₂/CS nanocomposite modified glassy carbon electrode (GCE) was used to construct a sensitive sensor for detecting lead ions in tobacco leaves. The reduced graphene oxide (rGO) was used to increase the conductivity of the sensor, and the nano-flowered MoS₂ could provide a large reaction specific surface area and a certain active site for heavy metal reaction. Chitosan (CS) was used to improve the enrichment ability of heavy metals and increase the electrocatalytic activity of electrode. Thus, an electrochemical sensor with excellent performance in reproducibility, stability and anti-interference ability was established. The stripping behavior of Pb(ii) and the application conditions of the sensor were studied by square wave anodic stripping voltammetry (SWASV). The investigation indicated that the sensor exhibited high detection sensitivity in the range of 0.005–0.05–2.0 μM, and the limit of detection (LOD) was 0.0016 μM. This work can provide a fast and effective method for determination of Pb(ii) in samples with low content, such as tobacco leaves.

High-performance electrode modification materials play a crucial role in improving the sensitivity of sensor detection in electrochemical determination of heavy metals.     

综合性肺康复治疗对稳定期慢性阻塞性肺疾病患者运动能力与生存质量影响

目的:探讨稳定期慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者门诊肺康复综合治疗的临床价值,分析肺康复综合治疗对稳定期COPD患者运动耐力及生存质量等方面的影响。方法:选取2012年11月—2013年10月医院收治的200例稳定期COPD患者为研究对象,随机分为对照组与观察组,对照组给予常规门诊康复训练:呼吸功能训练(缩唇呼吸、腹式呼吸)结合氧疗,观察组给予门诊综合康复训练(运动、呼吸肌、长期家庭氧疗、营养支持、健康教育、心理与行为干预),训练前测定COPD生存质量评分、6min步行距离、Borg评分及St George呼吸问卷(SGRQ)评分,1秒用力呼气容积(FEV1)与最大肺活量(FVC),计算FEV1/FVC,分别与训练2周、1个月、3个月、6个月、1年、2年复测上述指标,并进行比较。结果:观察组患者训练6个月、1年、2年后生存质量评分、SGRQ明显优于训练前(P0.05),观察组优于对照组(P0.05);观察组患者训练3个月、6个月、1年、2年后6min步行距离、Borg评分明显优于训练前(P0.05),观察组明显优于对照组(P0.05),两组训练6个月、1年、2年患者FEV1/FVC与训练前比较显著升高(P0.05)。结论:稳定期COPD患者行门诊综合康复治疗可显著改善运动能力,提高生存质量,呈现一定时间累积效应,长期训练效果更好。     

In situ synthesis of MoS2/graphene nanosheets as free-standing and flexible electrode paper for high-efficiency hydrogen evolution reaction

In this article, an exquisite flexible hybrid MoS₂/graphene free-standing electrocatalyst paper was fabricated by a one-step in situ solvothermal process. The assembled MoS₂/graphene catalysts exhibit significantly enhanced electrocatalytic activity and cycling stability towards the splitting of water in acidic solution. Furthermore, a strategic balance of abundant active sites at the edge of the S–Mo–S layers with efficient electron transfer in the MoS₂/graphene hybrid catalyst plays a key role in controlling the electrochemical performance of the MoS₂ nanosheets. Most importantly, the hybrid MoS₂/graphene nanosheet paper shows excellent flexibility and high electrocatalytic performance under the various bending states. This work demonstrates an opportunity for the development of flexible electrocatalysts, which have potential applications in renewable energy conversion and energy storage systems.

An improved flexible hybrid MoS₂/graphene free-standing electrocatalyst paper was fabricated by a one-step in situ solvothermal process for hydrogen evolution reaction applications.     

Effect of Different Proportions of Phenolics on Antioxidant Potential: Pointers for Bioactive Synergy/Antagonism in Foods and Nutraceuticals

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Phenolic compounds include a broad variety of antioxidant plant substances such as flavonoids that have in...     

Effect of porous structural properties on lithium-ion and sodium-ion storage: illustrated by the example of a micro-mesoporous graphene1−x(MoS2)x anode

In this work, we synthesized micro-mesoporous graphene_1−x(MoS₂)_x with different compositional ratios via co-reduction of graphite oxide and exfoliated MoS₂ platelets. We systematically studied the performance of the micro-mesoporous graphene_1−x(MoS₂)_x as anodes in lithium-ion batteries and sodium-ion batteries. The results show that the specific surface areas of the composites decrease with introducing MoS₂. The irreversible capacitance, which is related to the formation of solid electrolyte interphases, also decreases. Besides specific surface area, we found that micropores can benefit the lithiation and sodiation. We demonstrated that a specific charge capacity of 1319.02 mA h g⁻¹ can be achieved at the 50th cycle for the graphene_½(MoS₂)_½ anode in lithium-ion batteries. Possible relationships between such a high specific capacity and the micro-mesoporous structure of the graphene_1−x(MoS₂)_x anode are discussed. This work may shed light on a general strategy for the structural design of electrode materials in lithium-ion batteries and sodium-ion batteries.

In this work, we systematically studied the effect of porous structural properties on performance of the micro-mesoporous graphene_1−x (MoS₂)_x as anodes in lithium-ion and sodium-ion batteries.     

Electrochemical sensor based on a three dimensional nanostructured MoS2 nanosphere-PANI/reduced graphene oxide composite for simultaneous detection of ascorbic acid,dopamine, and uric acid

A three dimensional (3D) nanostructured composite based on the self-assembly of MoS₂ nanospheres and polyaniline (PANI) loaded on reduced graphene oxide (denoted by 3D MoS₂-PANI/rGO) was prepared via a feasible one-pot hydrothermal process. The 3D MoS₂-PANI/rGO nanocomposite not only exhibits good functionality and bioaffinity but also displays high electrochemical catalytic activity. As such, the developed 3D MoS₂-PANI/rGO nanocomposite can be employed as the sensing platform for simultaneously detecting small biomolecules, i.e., ascorbic acid (AA), dopamine (DA), and uric acid (UA). The peak currents obtained from the differential pulse voltammetry (DPV) measurements depended linearly on the concentrations in the wide range from 50 μM to 8.0 mM, 5.0 to 500 μM, and 1.0 to 500 μM, giving low detection limits of 22.20, 0.70, and 0.36 μM for AA, DA, and UA, respectively. Furthermore, the 3D MoS₂-PANI/rGO-based electrochemical sensor also exhibited high selectivity, good reproducibility and stability toward small molecule detection. The present sensing strategy based on 3D MoS₂-PANI/rGO suggests a good reliability in the trace determination of electroactive biomolecules.

A three dimensional (3D) nanostructured composite based on the self-assembly of MoS₂ nanospheres and polyaniline (PANI) loaded on reduced graphene oxide (denoted by 3D MoS₂-PANI/rGO) was prepared via a feasible one-pot hydrothermal process.     

Preparation and study of characteristics of LiCoO2/Fe3O4/Li2B2O4 nanocomposites as ideal active materials for electrochemical hydrogen storage

The nanocomposites of LiCoO₂/Fe₃O₄/Li₂B₂O₄ were designed by the Pechini route using different fuels for the optimization of their morphology and structure. Compared to other fuels, citric acid can act as both an ideal fuel and a capping agent. The ratio of the EG : H₂O mixture is another parameter, which was studied in terms of its effects on the structural characterization. The optimized sample with a rod shape was selected to compare with the bulk sample through electrochemical hydrogen storage capacity. The discharge capacity for rod-shaped nanocomposites measured was 1284 mA h g⁻¹. However, the discharge capacity for the bulk morphology was calculated to be about 694 mA h g⁻¹. The magnetic, electrochemical and structural analyses were performed to investigate the properties of LiCoO₂/Fe₃O₄/Li₂B₂O₄ nanocomposites.

To the best of our knowledge, for the first time, the effects of LiCoO₂/Fe₃O₄/Li₂B₂O₄ nanocomposites as a favorable hydrogen capacitor were investigated to enhance hydrogen storage performance.     

A nickel nanoparticle engineered CoFe2O4/SiO2–NH2@carboxamide composite as a novel scaffold for the oxidation of sulfides and oxidative coupling of thiols

The purpose of this work was to prepare a new Ni–carboxamide complex supported on CoFe₂O₄ nanoparticles (CoFe₂O₄/SiO₂–NH₂@carboxamide–Ni). The carboxamide host material unit generated cavities that stabilized the nickel nanoparticles effectively and prevented the aggregation and separation of these particles on the surface. This compound was appropriately characterized using FT-IR spectroscopy, FE-SEM, ICP-OES, EDX, XRD, TGA analysis, VSM, and X-ray atomic mapping. The catalytic oxidation of sulfides and oxidative coupling of thiols in the presence of the designed catalyst was explored as a highly selective catalyst using hydrogen peroxide (H₂O₂) as a green oxidant. The easy separation, simple workup, excellent stability of the nanocatalyst, short reaction times, non-explosive materials as well as appropriate yields of the products are some outstanding advantages of this protocol.

The preparation of a Ni–carboxamide complex supported on CoFe₂O₄ for the oxidation of sulfides and oxidative coupling of thiols.