A novel nanostructure of perpendicular ultrathin MoSe2 nanosheets directly grown on graphene was produced by a facile hydrothermal method in the presence of CTAB. The vertically-oriented and ultrathin MoSe2 nanosheets distribute uniformly on the surface of graphene, and the nanosheets are typically 2–3 layers, which is confirmed by TEM and red shift of the A1g Raman peak. In comparison with pure MoSe2 and MoSe2 nanospheres on graphene, vertically oriented MoSe2 nanosheets on graphene show enhanced organic dye adsorption ability and photocatalytic performance in the degradation of MB, RhB and MO under dark conditions and visible light irradiation. The excellent photocatalytic activity may be contributed by the unique perpendicular MoSe2 nanosheets with fully exposed active edges and hybridized with graphene for reduced electron–hole pair recombination.

Application of ZrB2–SiC ceramic at temperatures above 2500 °C requires evaluation of the ablation behavior of the material. The ZrB2–SiC ceramics with SiC contents of 15% and 30% in volume were fabricated by SPS under a temperature of 1580 °C. The ceramics were then ablated by an oxy-acetylene flame with a temperature of 3000 °C. It was found that ZrB2–SiC consists of three distinct ablation layers (ZrO2, SiO2-rich, and SiC-depleted) after ablation. The ablation mechanism revealed that ZrB2–SiC forms a SiO2-rich layer, which slows down the diffusion of oxygen but accelerates the active oxidation of SiC.

A heterostructure of MoSe2 nanosheets decorated on C/TiO2 nanobelts was successfully fabricated through a facile hydrothermal process with the assistance of glucose. Ultrathin MoSe2 nanosheets fully covered on TiO2 nanobelts were coupled with carbon components as strong skeletons, which possess high contact surface area, efficient electronic transport frameworks and sufficient void spaces. As expected, the MoSe2@C/TiO2 heterostructures exhibit remarkable cycling stability (discharge capacity of 987.4 mA h g−1 after 100 cycles at a current density of 500 mA g−1) and rate capability (retained capacity of 860 mA h g−1 even at a current rate of 3000 mA g−1) as anode materials in lithium-ion batteries. The excellent electrochemical performance can be attributed to the structural advantages of MoSe2@C/TiO2 heterostructures, enabling great potential as anode materials in lithium-ion batteries.

•Novel TiO2@PANI nanobelts were synthesized for the first time.•TiO2@PANI nanobelts showed an enhanced photocatalytic activity under visible light.•The enhanced activity was mainly due to the synergic effect between PANI and TiO2.•The hole and superoxide radicals are the two main photoactive species.The TiO2@PANI nanobelts were successfully prepared via an in-situ chemical oxidative polymerization method. The structure characterization clearly indicated that PANI could be well wedged with TiO2 nanobelts. Furthermore, compared with P25, TiO2 nanobelts and PANI, the photocatalysis of TiO2@PANI nanobelts were dramatically improved. And recycling experiments confirmed that the TiO2@PANI photocatalysts had excellent stability and cycle performance. In addition, by careful investigation of influence factors, a possible mechanism was proposed.

Herein, a strong heterojunction, consisting of SnO2 nanoparticles grown on layered g-C3N4 nanosheets, was rationally designed and successfully synthesized via a facile hydrothermal method. The morphology, chemical structure, optical and electronic properties of the obtained SnO2/g-C3N4 hybrid nanocomposites were characterized. Furthermore, the photocatalytic activity of the novel photocatalysts was assessed. The results clearly indicate that the SnO2/g-CN-72.12% nanocomposite photocatalysts shows a stable cycle performance and exhibits significantly enhanced photocatalytic activity, which is 89 and 17 times higher than those of pure SnO2 and g-C3N4, respectively. The synergistic effect of the SnO2/g-C3N4 heterojunction can effectively accelerate the separation of photo-generated carriers and enhance the efficiency of interfacial charge transfer, which are proposed to be responsible for the enhancement of the photocatalytic activities. This study provides a low-cost and large-scale synthesis route for the production of visible light responsive photocatalysts that have potential in environmental purification applications.

Amorphous carbon framework stabilized SnO2 porous nanowires (SnO2@C nanocomposites) were successfully synthesized through a hydrothermal-calcining method. The in situ formed amorphous carbon framework not only enhances the electron conductivity but also accommodates the volume expansion during the electrochemical cycling process. Benefiting from the structure and amorphous carbon framework, SnO2@C nanocomposites show ultra-excellent cycling performance, rate capability and high coulombic efficiency. At a rate of 782 mA g−1, their reversible capacity is as high as 751 mA h g−1 with no capacity fading after 160 cycles. These experimental findings may provide some insights to further improve the cyclability and rate capability of anode materials, paving the way for the next-generation high performance Li-ion batteries.

•We synthesized the CrSTO/g-CN nanocomposites via a green and facile method.•CrSTO/g-CN nanocomposites showed an enhanced visible light photocatalytic activity than CrSTO and g-C3N4.•A possible Z-scheme charge transfer mechanism was proposed in our paper.Herein, a green and facile strategy to prepare graphite carbon nitride hybridized chromium doping strontium titanate spheres (CrSTO/g-CN) nanocomposites was reported in this study. The structure characterization clearly indicated that the CrSTO spheres were successfully loaded on the g-C3N4 nano-sheets forming the CrSTO/g-CN heterojunction. Furthermore, the measurement of photocatalytic activity revealed that the as-prepared CrSTO/g-CN hybrid nanocomposites exhibit the considerable stability and significantly enhanced photocatalytic activity for the degradation of rhodamine B under visible light irradiation. Especially the photocatalytic activity of CrSTO/g-CN-70% was almost 4.5 times higher than that of pure g-C3N4 and 3.5 times higher than that of pure Cr-doped SrTiO3 respectively. The enhanced photocatalytic activity of the CrSTO/g-CN hybrid nanocomposites was due to a synergistic effect following the Z-scheme charge transfer mechanism to enhanced charge-separation ability. Therefore, the CrSTO/g-CN hybrid nanocomposites could be of potential interest for water splitting, new fuels synthesis and environmental remediation under natural sunlight.

One-dimensional semiconductor heterostructures with unique properties are suited to application in the photocatalysis field. In this study, rationally designed SnO2@TiO2 porous nanowire–nanosheet heterostructures were realized by a facile hydrothermal method via loading TiO2 nanosheets onto SnO2 porous nanowires. One-dimensional porous heterostructures formed via the self-assembly process. Due to the improved photon absorption ability and more active sites, the special heterostructures showed enhanced photocatalytic properties under mixed light, nearly 2.5 times faster than that of SnO2 porous nanowires. Our results suggest that the SnO2@TiO2 porous nanowire–nanosheet heterostructures are promising as photocatalysts.

Nanocomposites of reduced graphene oxide (RGO) sheets decorated with amorphous ruthenium oxide nanoparticles are fabricated through a one-pot hydrothermal process without additional dispersants. During the hydrothermal reduction, unilamellar graphene sheets with curved and veil-like morphology are formed and multilamellar graphene sheets are further separated by amorphous RuO2·xH2O with a particle size of 3–8 nm. The nanocomposites exhibit evident pseudo capacitance behavior and the comprehensive electrochemical performance is improved markedly compared with that of the single components. When the precursor ratio of graphene oxide (GO) to RuCl3·xH2O is 2:10, the graphene–RuO2 (GR) nanocomposite electrode achieves the highest specific capacitance of 542.5 F g−1 and the minimum ESR value of 1.21 Ω at 0.1 A g−1, retaining 94% after 1000 cycles at 1 A g−1. Thus graphene sheets/ruthenium oxide nanocomposites bode well for a promising candidate in supercapacitor technology.

•Advanced method for configuration classification of layers-composite is presented.•Graphene corrugation modulates the stacking arrangement of graphene and MoS2.•The bandgaps of all types graphene and MoS2 nanocomposite are opened.•All types graphene and MoS2 nanocomposites display an enhanced light absorption.The properties of graphene absorption on graphene-like material can be modulated by the stacking arrangement. Here, we propose a “least squares” classification method for analyzing configuration types of graphene/molybdenum disulfide heterobilayers (G/MoS2 HBLs) while binding energy, electronic structure and optical absorption of G/MoS2 HBLs are investigated via first principles calculations. Owing to the lattice mismatch, no traditional AA and AB stacking exist but AA- and AB-stacking-like configurations have been found. Paradoxically, AB-stacking-like configuration, generally as the most stable stacking sequence, does not correspond to the relaxed structure. We interpret this paradox in terms of graphene corrugation. A detailed analysis of the electronic structure indicates that bandgaps of all configurations types (types of G/MoS2 HBLs) are opened and tunable under the different interlayer distance. Furthermore, compared with monolayer MoS2, G/MoS2 HBLs display an enhanced light response, a promising feature for photocatalytic applications.

Rationally designed SnO2@CdS nanowire-quantum dots (QDs) heterostructures were realized by a wet-chemical method via hydroxide cluster growth mechanism on high crystalline quality SnO2 nanowires, which were synthesized by a vapor transport method. The heterostructures showed enhanced photon harvesting capability and photodetection sensitivity at visible regime than that of wide band gap homogeneous SnO2 nanowires, as characterized by UV-Vis absorption and photoconductivity measurements. In addition, the SnO2@CdS nanowire-QDs heterostructures showed enhanced photocatalytic activity by more than 109% in a conceptual demonstration of photodegradation of methylene blue solution. Our results suggest that the SnO2@CdS nanowire-QDs heterostructures exhibit considerable promise for highly sensitive visible-light photodetectors and highly efficient photocatalysis.

•We prepared a carbon fiber reinforced PyC/C-TaC/PyC layered-structure ceramic matrix by chemical vapor infiltration.•The flexural strength, fracture toughness can be improved when compared with C/C composites.•The residual oxide products at 900–1500 °C are all of Ta2O5 phase but with different crystal structures and morphologies.•The formation mechanism of β-Ta2O5 phase had been analyzed.A new kind of carbon fiber reinforced PyC/C-TaC/PyC layered-structure ceramic matrix composites (Cf/C-TaC composites) was prepared by chemical vapor infiltration. The middle C-TaC ceramic layer was a co-deposited layer of PyC and TaC phases, in which its structure can also be divided into three different zones, from amorphous near the inner PyC interface to equi-axial and then needle-like structures. Nano-indentation tests show that the hardness and elastic moduli of the C-TaC co-deposited ceramic layer are higher than the values of PyC layer, with the results of a higher flexural strength, fracture toughness of the as-prepared composites when compared with C/C composites. Cf/C-TaC composites show a complex relationship of mass gain/loss with oxidation temperature. The mass loss increases at 900–1300 °C; and begins to loss at 1400 °C, when the temperature reaches to 1500 °C, the mass losses acutely. XRD results show that the residual oxide products on the surface of Cf/C-TaC composites at 900–1500 °C are all of Ta2O5 phase but with different crystal structures and morphologies, including hexagonal (δ) structure with an amorphous morphology at 900 °C, orthorhombic (β) structure with a hexagonal-block or oval-shaped crystallite morphology at 1000–1300 °C, tetragonal (α) structure with square rectangular shape morphology, monoclinic (α’) structure with triangular shape morphology and triclinic (α’’) structure with rhombic/long-strip-shape morphology at 1400–1500 °C, which may have great influence on the oxidation-resistance of Cf/C-TaC composites. The formation mechanism of β-Ta2O5 phase had been analyzed by TEM. The oxide contains an amorphous matrix, in which crystallized β-Ta2O5 phase was nucleated and grown. The nucleation and growth process of crystallized β-Ta2O5 are both controlled by the rearrangement of lattice at the crystallite/amorphous matrix interface.

Four flavonoids quercetin (QU), luteolin (LU), taxifolin (TA) and (+)-catechin (CA) with the same A- and B-rings but different C-ring substituents have been investigated for their binding to bovine serum albumin (BSA) in the absence and presence of Cu2+ by means of various spectroscopic methods such as fluorescence, UV–visible and circular dichroism (CD). The results indicated that hydroxyl group at 3-position increased the binding affinities between flavonoids and BSA. The values of the binding affinities were in the order: QU > CA > TA > LU. The presence of Cu2+ affected the interactions of flavonoids with BSA significantly. The binding affinities of QU and TA for BSA were decreased about 6.7% and 13.2%. However, the binding affinities of LU and CA for BSA were increased about 43.0% and 20.7%. The formation of Cu2+–flavonoid complex and steric hindrance together influenced the binding affinities of QU, LU and TA for BSA, while the conformational change of BSA may be the main reason for the increased binding affinity of CA for BSA. However, the quenching mechanism for QU, LU, TA and CA to BSA was based on static quenching combined with non-radiative energy transfer irrespective of the absence or presence of Cu2+. The UV–visible results showed the change in BSA conformation and the formation of flavonoid–Cu2+ complex. The CD results also explained the conformational changes of BSA on binding with flavonoids.The presence of Cu2+ affected the binding affinities of flavonoids with different C-ring substituents for BSA distinctively.

•Hf(Ta)C coating was synthesized on graphite by LPCVD using HfCl4-CH4-H2-Ar system.•The Hf(Ta)C coating has nanocrystalline structure with Hf1−xTaxC embedding in carbon.•The rapid nucleation of carbon inhibits the growth of Hf0.7Ta0.3C grains.Hf(Ta)C ceramic coating was synthesized on graphite by low pressure chemical vapor deposition with gaseous mixtures of hafnium halide, tantalum halide, methane, hydrogen and argon. The phase composition and microstructure of as-prepared coating were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). The growth behavior of coating was also discussed. Results show that the as-prepared coating is composed of nano-sized Hf0.7Ta0.3C solid solution and rare of carbon. The Hf(Ta)C coating exhibits a nanocomposite structure with Hf0.7Ta0.3C grains embedding in amorphous carbon, which can be contributed to the rapid nucleation of Hf1−xTaxC, as well as the inhibition of carbon in the growth of Hf1−xTaxC grains.