Deliang Cui

Controlled fabrication of ultrathin-shell BN hollow spheres with excellent performance in hydrogen storage and wastewater treatment

We developed a facile template-free solid state synthesis route, by which BN hollow spheres (BNHSs) with ultrathin shells (1–3 nm) were successfully prepared. Furthermore, the shell thickness of the BNHSs could be effectively adjusted by varying the reaction temperature. The as-prepared BNHSs with ultrathin shells possess high specific surface area, large pore volume and high density structural defects. These characteristics result in the excellent performance of BNHSs in hydrogen storage and adsorption of organic pollutants from wastewater. The hydrogen uptake capacity is up to 4.07 wt.% at 298 K and 10 MPa. The maximum adsorption capacities for basic yellow 1 and methylene blue are 191.7 and 116.5 mg g−1, respectively. Besides, the BNHSs preferentially adsorb organic aromatic compounds from mixed solutions of aromatic dyes and heavy metal ions, so they can be used to separate and recover some valuable organic compounds from wastewater.

Preparation and Photocatalytic Properties of g-C3N4/TiO2 Hybrid Composite

g-C 3 N 4 /TiO 2 composite were prepared by hydrolysis of Ti(OC 4 H n 9 )4 and the precursors of g-C 3 N 4 at room temperature and annealing in nitrogen atmosphere. X-ray diffraction results revealed that all the products were anatase structure. The chemical nature of O, N of the g-C 3 N 4 /TiO 2 were identified by X-ray photoelectron spectroscopy, presenting N-Ti-O and N-Ti-N doping status of the composite. The g-C 3 N 4 /TiO 2 composite showed better photocatalytic activity for the UV and visible-light degradation of Rhodamine B.

Boron nitride nanocarpets: controllable synthesis and their adsorption performance to organic pollutants

Boron nitride (BN) nanocarpets were synthesized at 260 °C and 150 MPa by a hot-press benzene-thermal method, using NaN3 and NH4BF4 as the reactants. The as-prepared BN nanocarpets are constructed of thin BN nano-sheets and a large amount of twisted nanorods rooted onto these nano-sheets. Besides the high density structural defects, BN nanocarpets also have a rather large specific surface area of 117.2 m2 g−1. Due to these characteristics, BN nanocarpets exhibit a very quick adsorption rate for methylene blue (MB) and the capacity is as high as ∼272.4 mg g−1. Furthermore, these BN nanocarpets can also selectively adsorb methylene blue from a mixed solution of MB and CuSO4. It is reasonable to believe that BN nanocarpets may find wide applications in wastewater treatment and the recovery of valuable organic compounds from wastewater.

Facile synthesis of 3D boron nitride nanoflowers composed of vertically aligned nanoflakes and fabrication of graphene-like BN by exfoliation

Here, we present a facile solid phase method for preparing unique, 3D hexagonal boron nitride (hBN) nanoflowers, which are composed of vertically aligned BN nanoflakes. The growth process of BN nanoflowers is well-controlled by appropriately changing the reaction times and can be explained by a delayed-release mechanism. These BN nanoflowers present good thermal stability and high specific surface area. In addition, the nanoflakes composing the nanoflowers can be easily exfoliated into few-layered graphene-like BN, which is readily dispersible in strong polar organic solvents. By FTIR spectra and theoretical calculation, it is believed that the interaction of BN nanosheet and solvent predominately induces the exfoliation of graphene-like BN. Furthermore, the graphene-like BN film displays superhydrophobicity with a contact angle of 140°.

Preparation of InN nanocrystals by solvo-thermal method

Abstract Indium nitride (InN) nanocrystals were successfully prepared by the reaction of InCl 3 and Li 3 N at 250°C with xylene as the solvent. X-ray powder diffraction and TEM observation showed that the two phases of cubic InN and hexagonal InN coexist in the nanocrystals prepared by the solvo-thermal method.

Deep-blue electroluminescence from nondoped and doped organic light-emitting diodes (OLEDs) based on a new monoaza[6]helicene

A new organic electroluminescent material, monoaza[6]helicene (1), was successfully prepared via an effective photochemical reaction in about 10 minutes with high productivity. The thermal, photophysical, electrochemical properties, quantum chemical and X-ray structural studies as well as characteristics of organic light-emitting diodes were fully investigated. 1 exhibited excellent solubility and high thermal stability. The first singlet excitation energy of 1 was measured to be around 2.92 eV with a HOMO level of −5.19 eV and a LUMO level of −2.27 eV. Helical molecular geometry of 1 effectively blocked the π-conjugation and decreased the close-packing of molecules. Both the nondoped and doped OLEDs emitted deep-blue light at 444 and 462 nm with CIE coordinates of (0.15, 0.09) and (0.15, 0.10). The doped OLED based on 1 was the first example of helicenes as light emitters that exhibited a brightness of more than 3000 cd m−2 with high color purity and excellent efficiency stability.

Boron Nitride Ultrathin Fibrous Nanonets: One-Step Synthesis and Applications for Ultrafast Adsorption for Water Treatment and Selective Filtration of Nanoparticles

Novel boron nitride (BN) ultrathin fibrous networks are firstly synthesized via an one-step solvothermal process. The average diameter of BN nanofibers is only ~8 nm. This nanonets exhibit excellent performance for water treatment. The maximum adsorption capacity for methyl blue is 327.8 mg g(-1). Especially, they present the property of ultrafast adsorption for dye removal. Only ~1 min is enough to almost achieve the adsorption equilibrium. In addition, the BN fibrous nanonets could be applied for the size-selective separation of nanoparticles via a filtration process.

The effect of temperature on the synthesis of BN nanocrystals

Abstract Boron nitride (BN) nanocrystals have been synthesized by the reaction of Li3N and BBr3 in organic solvent. The experimental results indicated that, at low temperature, hexagonal BN (hBN) is the dominant phase in the sample. The content of cubic BN (cBN) increased with temperature, and it reached a maximum at 480°C. As the temperature increased further, the content of cBN decreased, and hBN became the dominant phase again. This phenomenon was discussed briefly in this paper.

Ultrathin BN nanosheets with zigzag edge: one-step chemical synthesis, applications in wastewater treatment and preparation of highly thermal-conductive BN–polymer composites

Ultrathin BN nanosheets (BNNSs) were prepared at 300 °C by a new variable-pressure one-step chemical synthesis route. It was found that the thickness of BNNSs decreased from 8 nm to 3 nm with the pressure increasing from 10 MPa to 90 MPa, and all the BNNSs are triangular in shape with a zigzag edge. These BNNSs have high specific surface area, and thus exhibit high adsorption capacities for the organic dye methylene blue (MB). The maximum specific surface area and adsorption capacity of BNNSs are 182 m2 g−1 and 436 mg g−1, respectively. Besides, the BNNSs can also be used as excellent thermal-conducting additives in BN–polymer (Nylon66 and polyvinyl alcohol (PVA)) composites. Especially, the thermal conductivity of BN–PVA film can be improved up to 3.44 times with only 3 wt% of BNNSs.

Growth of Large-Size SnS Thin Crystals Driven by Oriented Attachment and Applications to Gas Sensors and Photodetectors.

Freestanding large-size SnS thin crystals are synthesized via two-dimensional oriented attachment (OA) growth of colloidal quantum dots (CQDs) in a novel high-pressure solvothermal reaction. The SnS thin crystals present a uniform rectangular shape with a lateral size of 20-30 um and thickness of <10 nm. The evolution process demonstrates that a synergetic effect of pressure, aging time and organic ligands results in polycrystal-to-monocrystal formation and defect annihilation. Furthermore, gas sensor and photodetector devices, based on SnS thin single crystals, are also prepared. The sensing devices present high sensitivity, superior selectivity, low detection limit (≪100 ppb) and reversibility to NO2 at room temperature. The fabricated photodetector devices exhibit a high responsivity of 2.04 × 10(3) A W(1-) and high external quantum efficiency of ∼4.75 × 10(5) % at 532 nm, which are much higher than most of the photodetector devices.