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Although it is a promising sodium storage material due to its excellent electrochemical activity, small bandgap, and large interlayer spacing, layered molybdenum disulfide (MoS2 ) suffers from poor rate capability and degraded cycling life, resulting from its serious aggregation upon preparation, sluggish reaction kinetics, and structure expansion during cycling. To address these issues, a polyethyleneimine (PEI)-assisted fabrication approach was developed for the rational synthesis of an interconnected framework with nitrogen-doped carbon-confined MoS2 nanosheets/Ti3 C2 Tx MXene (MoS2 /Ti3 C2 Tx @NC), where the PEI could guide the uniform growth of MoS2 on Ti3 C2 Tx and the self-generated NC simultaneously enhanced its synergistic coupling with MoS2 /Ti3 C2 Tx , thus contributing to the improvement of charge transfer, diffusion kinetics, and structural integrity of the hybrid electrode. Consequently, the desired MoS2 /Ti3 C2 Tx @NC delivered impressive sodium storage performance, demonstrating high reversible capacities of 397.3 and 206.8 mAh g-1 at 0.1 A g-1 after 100 cycles and 0.5 A g-1 after 500 cycles, respectively. Moreover, electrochemical kinetics analysis and charge storage mechanism manifested that high capacitive contribution, facilitated Na+ transport pathways, and synergistic electronic coupling between MoS2 /Ti3 C2 Tx and NC contributed to the superior sodium storage performance.

Organic electrode materials with abundant resources, environmental friendliness and recyclability play a crucial role in rechargeable lithium-ion batteries (LIBs). However, the inferior electrical conductivity and unsatisfactory long-term cycling performance seriously impede their large-scale application in LIBs. Herein, a novel salen-based porous framework polymer (SPP) with a large conjugated skeleton was constructed and utilized as anode for LIBs. Owing to its unique architecture with a large conjugated skeleton facilitating the electron transport, rich pores accelerating the organic electrolyte infiltration, and stable skeleton structure improving the long-term cycling performance, SPP delivered a high specific capacity of 337 mA h g-1 at 0.1 C (1 C=250 mA g-1 ) after 100 cycles, and robust rate capacity of 95.5 mA h g-1 at 32 C. Importantly, an impressive long-term cycling performance with a storage capacity of 155.7 mA h g-1 at 8 C after 4000 cycles was obtained, showing a durable cyclic stability of SPP. Furthermore, the lithium storage mechanism of SPP was evaluated by ex-situ X-ray photoelectron spectroscopy, manifesting that the multiple active sites of C=N, -OH, and benzene ring were responsible for the superior lithium storage performance. The novel SPP presented in this work should be a promising organic electrode for energy storage applications.

As one of the low‐cost energy storage systems, Na‐ion batteries (NIBs) have received tremendous attention. However, the performance of current anode materials still cannot meet the requirements of NIBs. In our work, we obtain sulfur‐doped interconnected carbon microspheres (S‐CSs) via a simple hydrothermal method and subsequent sulfurizing treatment. Our S‐CSs exhibit an ultrahigh reversible capacity of 520 mAh g–1 at 100 mA g–1 after 50 cycles and an excellent rate capability of 257 mAh g–1, even at a high current density of 2 A g–1. The density functional theory calculations demonstrate that sulfur doping in carbon favors the adsorption of Na atom during the sodiation process, which is accountable for the performance enhancement. Furthermore, we also utilize operando Raman spectroscopy to analyze the electrochemical reaction of our S‐CSs, which further highlights the sulfur doping in improving Na‐ion storage performance.

One of the most challenging issues in developing capacitive deionization (CDI) technologies is the rational design and synthesis of active electrode materials with favorable morphologies and high surface areas. Here, for the first time, shuttle-like porous carbon rods (sPCRs) were prepared through a high temperature pyrolysis step and a subsequent etching step by using rod-like metal–organic frameworks, MIL-88 (Fe), as the precursor. The correlation between the carbonization temperature of sPCRs and their electrosorption performance was investigated, and it was found that, owing to their unique shuttle-like rod structure and high specific surface area, sPCRs obtained at 900 °C exhibit a superior electrosorption capacity of 16.2 mg g−1 with excellent cycling stability, showing that sPCRs could be a promising electrode material for highly efficient CDI.

Highly conductive, crystalline, polymer electrolytes, β-cyclodextrin (β-CD)-polyethylene oxide (PEO)/LiAsF6 and β-CD-PEO/NaAsF6 , were prepared through supramolecular self-assembly of PEO, β-CD, and LiAsF6 /NaAsF6 . The assembled β-CDs form nanochannels in which the PEO/X(+) (X=Li, Na) complexes are confined. The nanochannels provide a pathway for directional motion of the alkali metal ions and, at the same time, separate the cations and the anions by size exclusion.

A reduced graphene (RG)-Au nanoparticle composite film is successfully fabricated by electrophoretic deposition and used as counter electrode for quantum dot-sensitized solar cells. The RG-Au composite is prepared by one-step microwave-assisted reduction of chloroaurate in alkaline solution with graphite oxide dispersion. Under one sun illumination (AM 1.5 G, 100 mW cm(-2)), the cell with a RG-Au counter electrode shows an energy conversion efficiency of 1.36 %, which is higher than those of cells employing conventional Pt or Au counter electrodes, due to the superior combination of highly catalytic Au nanoparticles and the conductive graphene network structure.

Graphene was synthesized by the modified Hummers method and a hydrazine reduction process. The obtained graphene was characterized by various diagnostic techniques, such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). A layer of transparency crumpled film was obtained with an interlayer spacing of 0.37 nm. The two typical peaks of 3415 and 1091 cm−1 correlated to OH and CO were observed from the FTIR spectrum. The samples showed an enhanced thermal stability promoting the way for the research and the applications of graphene.

This paper presents a comparative study on electrosorptive behavior of activated carbon fiber (ACF), carbon nanotube (CNT) and carbon nanotube-carbon nanofiber (CNT-CNF) composite in NaCl solution. The result shows that CNT-CNF exhibits a higher NaCl removal ratio with a faster electrosorption rate than ACF and CNT due to its more hydrophilic surface, higher specific capacitance and more suitable mesoporous structure (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Dispersed and spherical Y2O3:Eu3+ red phosphor particles were prepared by the urea homogeneous precipitation method. In2O3 nanoparticles were successfully coated on the surface of the phosphor. Phase compositions, morphologies, photoluminescence (PL) spectra, and cathodoluminescence (CL) properties of Y2O3:Eu3+ phosphors before and after In2O3 coating were examined. It was found that CL properties such as luminous efficiency, lifetime, and stability of In2O3-coated phosphor screen were improved significantly, even though its PL intensity decreased compared with that of the uncoated sample. The reason is attributed to the increase of the electrical conductivity and the decrease of the charge accumulating effect. The present results prove that Y2O3:Eu3+ phosphor coated with an appropriate amount of In2O3 is more suitable to the requirement for low-voltage field-emission displays.

Consistent insight is presented into the atomistic origin and temperature (T) dependence of the redshift of Raman optical modes in nanostructures from the perspective of surface bond unsaturation and the bond-order-length-strength (BOLS) correlation [Sun et al., Phys Rev B 72, 134301 (2005)]. It turns out that: (1) the size-induced redshift of Raman optical modes results from the effect of bond order deficiency of atoms on the surface and its consequences on the force constants of bonds between the under-coordinated surface atoms; (2) the temperature-induced redshift arises from thermally induced bond expansion and bond weakening and (3) the magnitude of vibration of atoms in the surface or surrounding defects is always greater than the fully coordinated bulk atoms, while the frequency of such under-coordinated atoms are relatively lower. It is demonstrated that a combination of the freedoms of solid size and temperature of testing with Raman spectroscopy could lead to information about the vibrational frequency of a monatomic chain and single-bond energy, which is beyond the scope of the traditional size- and temperature-independent approaches. Copyright  2007 John Wiley & Sons, Ltd.

Highly conductive, crystalline, polymer electrolytes, β-cyclodextrin (β-CD)-polyethylene oxide (PEO)/LiAsF6 and β-CD-PEO/NaAsF6 , were prepared through supramolecular self-assembly of PEO, β-CD, and LiAsF6 /NaAsF6 . The assembled β-CDs form nanochannels in which the PEO/X(+) (X=Li, Na) complexes are confined. The nanochannels provide a pathway for directional motion of the alkali metal ions and, at the same time, separate the cations and the anions by size exclusion.

A facile and pollution-free method was applied to prepare graphene nanosheets by reducing graphene oxide in acidic aqueous solution without any toxic chemicals via microwave heating. The surface morphology, structure, and composition characterizations were carried out using atomic force microscopy, field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy, respectively. The results showed that high-quality and large-area reduced graphene nanosheets were obtained.

Nanostructured photocatalysts have attracted considerable interest due to their wide range of applications in processes such as organic pollutant degradation, heavy metal reduction, air and water purification, hydrogen production, etc. Pursuing high catalytic efficiency is the foremost goal in the field. One of the current key issues is to search for suitable photocatalysts to enhance light harvesting in the UV or visible light region. In this treatise, the microwave-assisted solution-phase synthesis of various nanomaterials including semiconductor oxides and sulfides, Bi-based oxides, as well as nanocomposites including carbon nanotube-based and graphene-based composites is systematically presented with demonstrations of the advantages of the microwave-assisted process over traditional synthesis methods including solid state or vapor reactions and hydrothermal or solvothermal processes. Application of these nanomaterials as photocatalysts for the degradation of pollutants in water or air, removal of Cr(VI) as well as hydrogen evolution is also demonstrated, showing the improved photocatalytic activities compared with the ones synthesized via traditional methods.

Understanding the blue shift in the photoluminescence (PL) of the nanosolid near the lower end of the size limit (D < 5 nm) seems difficult with the currently available models. This challenges are ...