Hexagonal boron nitride (h-BN) nanosheets are prepared by a novel and effective method, in which sodium hydroxide and potassium hydroxide molten salts are used to exfoliate h-BN to obtain nanosheets. BN nanoscrolls are also obtained. The as-prepared products can be readily dispersed in a wide range of solvents, including water and ethanol, and form stable dispersions.

Owning many peculiar properties, hexagonal boron nitride nanosheets (BNNSs) have lots of potential applications, such as electronic devices and deep ultraviolet emitters. In this article, a chemical exfoliation method to prepare few-layer and large size BNNSs is reported. Through related instrument characterizations, we demonstrated that this preparation method can allow the exfoliation of BNNSs from bulk BN powder successfully. From CL spectra, the as-prepared BNNSs were proved to show stronger CL emission ability than BN powder. Based on the experiment results analysis, we proposed an exfoliation mechanism and verified it through in situ SEM detection.

A novel, simple, and efficient method for the preparation of the fluorinated hexagonal boron nitride nanosheets (F-BNNSs) and the corresponding magnetic properties is presented. A one-step route is used to exfoliate and fluorinate the BNNSs by ammonium fluoride (NH4F) from hexagonal boron nitride (h-BN) powder. Through related instrument characterizations and theoretical calculations, we confirm that large-area and few-layer F-BNNSs were successfully produced by this method, which can be attributed to a fluorination-assisted exfoliation mechanism from the bulk h-BN in NH4F. More intriguingly, we initially verified that the as-prepared F-BNNSs exhibit ferromagnetic characteristics, which would have good potential applications in spintronic devices.

Various lead-free (K x Na 1Àx ) 0.98 Li 0.02 (Nb 0.82Ày Ta 0.18 Sb y )O 3 ceramics with x 5 0.50, y 5 0.00-0.07 or x 5 0.40-0.60, y 5 0.05 were prepared by the conventional solid-state reaction method. Systematic investigation on the microstructures, crystalline structures, and dielectric and piezoelectric properties was carried out. Remarkably strong piezoelectricity has been achieved in (K 0.45 Na 0.55 ) 0.98 Li 0.02 (Nb 0.77 Ta 0.18 Sb 0.05 )O 3 ceramic, which shows the excellent piezoelectric properties of d 33 5 413 pC/N, d 31 5 À153 pC/N, k p 5 0.50, and k 33 5 0.62. It is considered that the observed strong piezoelectricity should be ascribed to several combined decisive factors, such as the phase coexistence due to an orthorhombic-tetragonal polymorphic phase transition near room temperature, the high electronegativity of Sb 51 ions as compared with those of Nb 51 ions and Ta 51 ions, and the relatively ideal microstructure with high density, large average grain size and narrow grain-size distribution.

Two-dimensional atomically thick materials, reduced graphene oxide (RGO), and layered molybdenum disulfide (MoS ) have been investigated as potential novel energy storage materials because of their distinct physicochemical properties. These materials suffer, however, from rapid capacity decay and low rate capability. This study describes a facile, binder-free approach to fabricate large-scale, 3D network structured MoS @carbon nanotube (CNT)/RGO composites for application in flexible supercapacitor devices. The as-obtained composites possess a hierarchical porosity, and an interconnected framework. The electrochemical supercapacitive measurements of the MoS @CNT/RGO electrode show a high specific capacitance of 129 mF cm at 0.1 mA cm . The symmetric supercapacitor devices based on the as-obtained composites exhibit a long lifetime (94.7 % capacitance retention after 10 000 cycles), and a high electrochemical performance (29.7 mF cm ). The present experimental findings will lead to scalable, binder-free synthesis of MoS @CNT/RGO hybrid electrodes, with enhanced, flexible, supercapacitive performance, in portable and wearable energy storage devices.

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Combining 2D MoS2 with other transition metal sulfide is a promising strategy to elevate its electrochemical performances. Herein, heterostructures constructed using MnS nanoparticles embedded in MoS2 nanosheets (denoted as MnS‐MoS2) are designed and synthesized as anode materials for lithium/sodium‐ion batteries via a facile one‐step hydrothermal method. Phase transition and built‐in electric field brought by the heterostructure enhance the Li/Na ion intercalation kinetics, elevate the charge transport, and accommodate the volume expansion. The sequential phase transitions from 2H to 3R of MoS2 and α to γ of MnS are revealed for the first time. As a result, the MnS‐MoS2 electrode delivers outstanding specific capacity (1246.2 mAh g−1 at 1 A g−1), excellent rate, and stable long‐term cycling stability (397.2 mAh g−1 maintained after 3000 cycles at 20 A g−1) in Li‐ion half‐cells. Superior cycling and rate performance are also presented in sodium half‐cells and Li/Na full cells, demonstrating a promising practical application of the MnS‐MoS2 electrode. This work is anticipated to afford an in‐depth comprehension of the heterostructure contribution in energy storage and illuminate a new perspective to construct binary transition metal sulfide anodes.

High-quality graphene sheets with lateral size over 20 μm have been obtained by bath sonicating after subjecting the wormlike graphite marginally to mixed oxidizer. To date, to our knowledge, they are the largest graphene sheets prepared by exfoliation in the liquid phase. A saturable absorber mirror was fabricated based on these sheets. We exploited it to realize mode-locking operation in a diode-pumped Nd:GdVO(4) laser. A pulse duration of 16 ps was produced with an average power of 360 mW and a highest pulse energy of 8.4 nJ for a graphene mode-locked laser.