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Abstract α-Fe 2 O 3 nanoparticles with different sizes were successfully synthesized by a simple SDS-assisted grinding reaction and subsequent heating treatment process. Effects of calcination temperatures on crystal structure, optical and photocatalytic properties of the products were investigated by TG-DSC, FTIR, XRD, TEM, HRTEM, and UV–Vis techniques. Results showed that growth of the α-Fe 2 O 3 nanoparticles was very slow, and the average crystallite size gradually increased with increasing calcination temperatures. Optical measure and calculation showed that there is an increasing trend for the band gap with increase of calcination temperature. The α-Fe 2 O 3 nanoparticles obtained at 500 °C revealed higher photocatalytic degradation efficiency for MB than the other samples, attributing to the optimal value between transiting electrons and recombination of electron-hole pairs. Radical scavengers experiments implied that ·OH and e− played important roles in the photocatalytic process. The photodegradation time was greatly shortened, and the photocatalytic efficiency was further enhanced and raised to over 90% after adding H 2 O 2 , which is due to generation of a large number of the highly oxidative ·OH by photo-Fenton reaction. Highlights • α-Fe 2 O 3 nanoparticles were successfully synthesized by decomposing precursor. • Precursor was obtained by a simple SDS-assisted grinding reaction. • High photocatalytic efficiency of 99.6% was obtained for α-Fe 2 O 3 within 40 min. • It is due to generation of a large number of the ·OH by Photo-Fenton reaction. [ABSTRACT FROM AUTHOR]

Cu 2 S thin films were successfully grown in situ on Cu foil by an easy hydrothermal method. The effects of surfactant and reaction time on the formation of the Cu 2 S films were studied by X-ray diffraction, field-emission scanning electron microscopy and ABIOS profilometry. Results showed that the thin films consisted of nanoparticles, and their crystallization and surface roughness depended on the structures of surfactants and reaction time. Photocatalytic studies indicated that the film obtained at 1 h by the EDTA-2Na surfactant exhibited a good methylene blue degradation rate of 83.7%, and higher values of 89.2% and 90% were obtained with increased reaction time to 3 and 4 h. Even the decomposition rate remained at high (82%) after reuse. This good catalytic performance can be attributed to the heterojunction formed between Cu and Cu 2 S, the special surface from the reaction between [Cu-EDTA] - ion and S 2− , and the further crystal orientation with prolonged reaction time. [ABSTRACT FROM AUTHOR]

A simple low-temperature solid-state reaction in the presence of the surfactant PEG400 was developed to obtain ZnO/CdS nanocomposites. The effects of synthesis temperature and reaction time on crystal structure and optical properties of the nanocomposites were investigated by several technologies. X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) characterizations showed that the products consisted of the nanoparticles, and the grain growth kinetics of the cubic CdS and the hexagonal ZnO phase in the nanocomposites was described. The mechanism analysis suggested that sufficient grinding and heating treatment was a key to form the ZnO/CdS nanocomposites, and the surfactant PEG400 was proved not to involve the reaction and prevent the nanoparticles from aggregating to larger in whole grinding and heat-treatment process. Ultraviolet–visible (UV–vis) spectra revealed that the band gaps of the nanocomposites could be tuned by the reaction temperature and reaction time. Photoluminescence (PL) spectra showed that the changing position and the intensity of the emission peaks resulted from the rate of electron transfer and recombination probability under the different conditions. [ABSTRACT FROM AUTHOR]

Abstract: A simple low-temperature solid-state synthetic method was employed to obtain ZnS–CdS and CdS–ZnS alloy nanoparticles. The effects of reaction sequence, reactant molar ratios, and synthesis temperature on the products were investigated. The crystal structure and morphology of the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and fourier transform infrared (FT-IR) spectroscopy. The results show that the products are alloy nanoparticles with a cubic phase structure. The formation mechanism of the alloy nanoparticles is briefly discussed. Sufficient grinding and crystalline water may be essential to form alloy nanoparticles. Ultraviolet–visible (UV–vis) spectra show that the edge absorptions of the CdS–ZnS and ZnS–CdS nanoparticles were located between those of ZnS and CdS bulks, and the absorbance at the peak maximum was practically dependent on reaction temperature, reaction sequence, and molar ratio. Extrinsic deep-level emission resulted in strong peaks in the photoluminescence (PL) spectra. The position and intensity of the emission peaks varied with the conditions during synthesis. [Copyright &y& Elsevier]

AgI nanoparticles decorated with ZnO flower-like composites were successfully synthesized via citric acid-induced hydrothermal reaction and subsequent chemical deposition in the presence of ammonium hydroxide. The effects of AgI-loading content and the piezoelectric effect of ZnO were investigated using different technologies. The crystal structures and optical and photocatalytic properties revealed that the AgI particles were successfully loaded on the flower-like ZnO through the directed diffusion process of charge-induced deposition. Results also showed that the band gap of the AgI/ZnO composite located between those of the ZnO and the AgI, which was consistent with the theoretic simulation. The degradation rate of RhB induced by the AgI/ZnO composites was three times larger than that of AgI, and the heterojunction exhibited high photocatalytic degradation efficiency for MO and TC. Besides, the photodegradation efficiency remained high after six times. Radical scavenger experiments implied that e− and h+ played important roles in the photocatalytic process. The photodegradation time was considerably shortened while maintaining increased degradation efficiency after adding ultrasonic vibration due to the rapid separation of carriers caused by the piezo-photocatalysis coupling effect. • AgI/ZnO heterostructures were synthesized by a simple chemical deposition. • High degradation efficiency and excellent reusing activity was obtained. • It is due to rapid separation of dominant e− and h+ from AgI/ZnO heterostructure. • Degradation time was greatly shortened under ultrasonic vibration. [ABSTRACT FROM AUTHOR]

Abstract: The microstructures and tensile properties of a Mg–6Zn–4Si alloy with calcium additions at ambient and elevated temperature were investigated by means of X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and standard high temperature tensile testing. The results indicate that the morphology of the primary Mg2Si in the alloys changes from large dendritic (>100μm) to fine polygon (<20μm). Meanwhile, the eutectic Mg2Si changes gradually from Chinese script shape to a fine fibre morphology with increasing Ca content. The grain size of the primary Mg2Si decreases initially and then slowly increases with increasing Ca content. Experimental analysis shows that the concentration distribution of Ca atoms on the growth front of the Mg2Si cause a “poisoning effect”. The coarse CaMgSi compound is formed due to an excessive Ca addition, which resulted in the over-modification. Therefore, it can be concluded that the appropriate level of Ca addition can both effectively modify and refine the primary Mg2Si, and also decrease the amount of the primary Mg2Si. Tensile testing results show that the addition of Ca improves the ultimate strength, yield strength and elongation of the Mg–6Zn–4Si alloys at both ambient temperature and 150°C. Optimal mechanical properties can be achieved with a Ca addition of 0.4%. [Copyright &y& Elsevier]

The design of a reasonable structure and component regulation are valid methods for enhancing the electrochemical properties of TiO 2 , which serves as prominent anode in sodium-ion batteries with exceptional structural stability. Herein, the carbon-coated anatase TiO 2 doped with S (S-TiO 2 @C) was synthesized via a facile metal-organic framework-assisted approach. The S atoms partially substitute oxygen atoms in the lattice, thereby enhancing the capacitive behavior, facilitating charge transfer kinetics, and augmenting the diffusion coefficient of Na+. With exceptionally high porosity and substantial carbon content, the caky S-TiO 2 @C electrode manifests superior rate capability of 167.7 mAh g−1 at 5.0 A g−1 and long-cycle life of 239.0 mAh g−1 at 2.0 A g−1 over 4000 cycles. It is foreseeable that the strategy of anionic doping and carbon coating on the metal oxide with porous structure to optimize the sodium storage capability of the electrode will be applied in the future. • Metal-organic framework derived S-doped TiO 2 with carbon coating was synthesized for the first time. • The high level of porosity facilitates electrolyte infiltration and offers more active sites for sodium storage. • The S atoms partially substitute oxygen atoms in the lattice, thereby enhancing the kinetics of sodium storage. • The S-TiO 2 @C electrode exhibits superior rate capability and long-term cycle stability over 4000 cycles. [ABSTRACT FROM AUTHOR]

In recent years, large and small industries have discharged a multitude of organic pollutants into the environment, causing environmental pollution. Titanium dioxide (TiO 2) materials is very important photocatalyst as a result of its outstanding applications to remove organic contaminants from the environment. Nonetheless, the low utilization rate of visible light of TiO 2 has limited its application. To begin with, Black TiO 2 is produced by the magnesium thermal reduction method to promote the absorption of visible light, Subsequently, The black TiO 2 /SnO 2 composites are synthesized by chemical synthesis method to form a hetero-junction to augment the photocatalytic activity. The morphology, chemical composition, phase structure and photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation were investigated. The morphological properties demonstrated that a Ti3+ self-doped disorder layer forms on the surface of TiO 2 nanophase, and black TiO 2 nanoparticles are well decorated with SnO 2 nanoparticles. After 90 min of visible light irradiation, RhB has a photocatalytic degradation efficiency of 96.62%, which is 1.597 times that of TiO 2 nanoparticles, and its cycle stability is well beyond our expectation. The ameliorated photocatalytic degradation performance of TiO 2 /SnO 2 composite is ascribed to the formation of a "type Ⅱ heterojunction", which not only reinforces the absorption of visible light of black TiO 2 /SnO 2 nanoparticles, but also heightens the separation and transfer efficiency of the photogenerated carriers. • The black TiO 2 /SnO 2 composite are prepared to improve the photocatalytic activity. • The black TiO 2 are well decorated with SnO 2 nanoparticles to form "type Ⅱ heterojunction". • The composite exhibits an excellent visible-light photocatalytic performance and cycle stability. • The composite improve absorption of visible light and separation of the photogenerated carriers. [ABSTRACT FROM AUTHOR]

An interrupted aging treatment, T6I6, was conducted on 2195 Al-Cu-Li alloy to improve the corrosion resistance. The microstructure evolution, intergranular corrosion (IGC), exfoliation corrosion (EXCO), and electrochemical corrosion behaviors of 2195 Al-Cu-Li alloy subjected to T6I6 and T6 aging treatment were systematically investigated. The results reveal that the number density of T 1 (Al 2 CuLi) phases in the grain interior and at the grain boundaries of T6I6 sample increases by suppressing the precipitation of θ' (Al 2 Cu) phases. The higher density of T 1 phases along the grain boundary can increase the potential difference between the grain boundary precipitates (GBPs) and Al matrix, resulting in decreased corrosion resistance. However, the GBPs coarsening and precipitate free zone (PFZ) narrowing induced by interrupted aging offset the harmful effects of T 1 phases, which are responsible for the improved corrosion resistance of T6I6 sample. Hence, the proposed T6I6 aging treatment more effectively improves the corrosion resistance for the studied alloy compared to T6 aging. • The T6I6 can significantly improve the IGC, EXCO, and electrochemical corrosion resistances of 2195 Al-Cu-Li alloy. • The precipitation kinetics of T 1 phases are promoted by interrupted aging, but those of θ' phases are inhibited. • The length, rather than the thicknesses of θ' and T 1 phases, is affected by interrupted aging. • The GBPs coarsening and PFZ narrowing induced by interrupted aging offset the harmful effects of T 1 phases. [ABSTRACT FROM AUTHOR]

As one of binary transition metal oxides, NiCo 2 O 4 (NCO) suffers from several problems like self–agglomeration and drastic volume change when used as an anode for lithium–ion batteries (LIBs). Herein, we propose a facile one–step hydrothermal method combined with heat treatment to prepare a hierarchical micro–nano hydrangea–like NiCo 2 O 4 /V 2 O 3 composite array (denoted as NCO/VO) on a nickel foam substrate as a free–standing anode for LIBs. The V 2 O 3 is introduced to form a composite structure with NCO, improving the electronic and ionic conductivity of the electrode. The synergistic effect of porosity, composite structure and micro–nano architecture offers the electrode excellent electrochemical performance. The specific capacity of the as–prepared electrode is 1155.6 mA h g−1 after 200 cycles under the current density of 100 mA g−1, with a retention ratio of 91.02 %. When the current density rises to 1000 mA g−1, it delivers a specific capacity of 750 mA h g−1, showing excellent rate performance. This work demonstrates that NCO/VO–NF is a promising candidate anode for next–generation LIBs. [Display omitted] • A first–time synthesis of NiCo 2 O 4 –V 2 O 3 composite arrays on nickel foam by a facile method. • The unique hierarchical micro–nano hydrangea–like morphology. • Improved electrochemical performances as an anode for LIBs by introducing V 2 O 3. [ABSTRACT FROM AUTHOR]

NiO–NiSe nanocomposite thin films are successfully fabricated by pulsed laser deposition (PLD) method and electrochemical properties of this composite are investigated by cyclic voltammetry and discharge/charge measurements. NiO–NiSe composite electrode delivers an initial discharge capacity of 577.7 mAh·g −1 and retains reversible capacity of 495 mAh·g −1 after 50 cycles, which exhibits significant improvement in cycling stability when compared with NiO thin film electrode. The electrochemical reaction mechanism of NiO–NiSe with lithium is examined by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) techniques. The decomposition reactions of NiO–NiSe with Li to form metal Ni, Li 2 O and possible small nanosized Li 2 Se during discharge process, and the reformation of NiO–NiSe nanocomposite after charge process are revealed. [ABSTRACT FROM AUTHOR]

Abstract: High-density Co3O4 nanowire arrays have been fabricated by a simple, solvent-free synthesis method inside the alumina pores. It has been found that the pore diameter played a key role in the formation of the Co3O4 nanowires. When the same reaction was performed in the narrow pores of the AAO template (<90nm), a mixture of nanoparticles and short nanorods were obtained. The nanorod consists of a lot of obvious grains, which form grain chains. However, continuous and uniform nanowires could be produced when the larger pores of AAO (>120nm) were applied. Selected-area electron diffraction (SAED) patterns revealed that the nanowires were single-crystalline. Electrochemical measurements by an electrochemical workstation indicate that the specific capacitance characteristics of the as-prepared Co3O4 nanowires are much higher than that of Co3O4 particles. [Copyright &y& Elsevier]

Abstract: Cuspate deltoid cobaltous oxide (CoO) crystallites with an average grain size of 3μm were obtained via developing the Co3O4 nanoplatelets under the KCl/NaCl flux atmosphere. The as-synthesized products were characterized by powder X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscope and selected area electron diffraction. The electrochemical properties of the products were investigated by an Electrochemical Workstation device at room temperature. It has been found that the final prepared cubic CoO crystallites are of uniform cuspate deltoid morphology. The results of electrochemical tests indicate that the CoO shows acceptable capacitive behavior with specific capacitance about 88F/g. [Copyright &y& Elsevier]

• 2D V 6 O 13 nanosheets were one-step synthesized using URH for the first time. • URH is a simple, low–energy consumption, time-saving, and efficient synthesis technology. • The as-synthesized material has a superior rate/cycle performance and enhanced reversible capacity. The ever-growing demands of Lithium-ion batteries (LIBs) for high-energy and long-life applications, such as smart grids and electrical vehicles, have drawn great research interest. Herein, 2D V 6 O 13 nanosheets with good crystallinity and robust configuration are in situ synthesized by applying an interesting one-step uniform rotate hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were carried out to characterize the crystal structure and micromorphology of the samples. In addition, the lithium storage performance of the sample was investigated through cyclic voltammetry, electrochemical impedance spectroscopy, and charge/discharge tests. Their capacity is up to 240 mAh g-1 at a current density of 100 mA g-1, corresponding to an initial Coulombic efficiency as high as 98.41%. Moreover, the capacity of 199 mAh g-1 can be delivered at a large current density of 500 mA g-1, and 87% of the capacity can be retained after 100 cycles. Even at a larger current density of 1000 mA g-1, they can still deliver a high capacity of 155.7 mAh g-1, and nearly 80% of the initial capacity can be kept after 300 cycles. This result is much higher than that of V 6 O 13 prepared by traditional hydrothermal method under the same test conditions. These results demonstrate that the as-synthesized 2D V 6 O 13 nanosheets by uniform rotate hydrothermal method have a promising future for high-rate and long-life cathode materials of next-generation LIBs. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) are considered promising energy storage devices owing to the abundant reserve and low-cost accessibility of Na resources. However, such batteries suffer from poor electrochemical performance due to the larger diameter of Na ions (0.106 nm). In this study, nitrogen-doped carbon-coating interlayer-expanded MoS 2 porous nanosheets (MoS 2 @N–C) were synthesized, and their structural, morphological, and electrochemical properties were characterized. The XPS and EDS indicated the successful introduction of carbon into the MoS 2 nanosheets. The interlayer spacing for (002) plane was increased from 0.62 nm to 0.78 nm corresponding to the shift toward lower angles shown in XRD. The MoS 2 @N–C exhibited an impressively high reversible capacity of 352 mAh/g at a current density of 100 mA/g after 200 cycles; this capacity is five times higher than that of bare MoS 2. Moreover, MoS 2 @N–C showed excellent rate performance due to the boosted diffusion of Na ions. The observed improvement in the electrochemical performance of MoS 2 @N–C demonstrates that the combination of suitable composite materials and interlayer expansion are effective strategies for battery technologies based on the storage of large ions. Image 1 • A high-temperature mixing method under hydrothermal conditions was utilized. • CTAB acts as intercalating reagent to perform interlayer engineering for MoS 2 @N–C. • The porous, flower-like few-layered MoS 2 @N–C nanosheets were obtained. • The interlayer spacing of (002) planes of MoS 2 @N–C increased from 0.62 nm to 0.78 nm. • The physical mechanisms for the enhanced electrochemical properties were addressed. [ABSTRACT FROM AUTHOR]