anlie Yu

Boron nitride nanosheets as improved and reusable substrates for gold nanoparticles enabled surface enhanced Raman spectroscopy

Atomically thin boron nitride (BN) nanosheets have been found to be excellent substrates for noble metal particles enabled surface enhanced Raman spectroscopy (SERS), thanks to their good adsorption of aromatic molecules, high thermal stability and weak Raman scattering. Faceted gold (Au) nanoparticles have been synthesized on BN nanosheets using a simple but controllable and reproducible sputtering and annealing method. The size and density of the Au particles can be controlled by sputtering time, current and annealing temperature etc. Under the same sputtering and annealing conditions, the Au particles on BN of different thicknesses show various sizes because the surface diffusion coefficients of Au depend on the thickness of BN. Intriguingly, decorated with similar morphology and distribution of Au particles, BN nanosheets exhibit better Raman enhancements than silicon substrates as well as bulk BN crystals. Additionally, BN nanosheets show no noticeable SERS signal and hence cause no interference to the Raman signal of the analyte. The Au/BN substrates can be reused by heating in air to remove the adsorbed analyte without loss of SERS enhancement.

Selective separation of oil and water with mesh membranes by capillarity

The separation of oil and water from wastewater generated in the oil-production industries, as well as in frequent oil spillage events, is important in mitigating severe environmental and ecological damage. Additionally, a wide arrange of industrial processes require oils or fats to be removed from aqueous systems. The immiscibility of oil and water allows for the wettability of solid surfaces to be engineered to achieve the separation of oil and water through capillarity. Mesh membranes with extreme, selective wettability can efficiently remove oil or water from oil/water mixtures through a simple filtration process using gravity. A wide range of different types of mesh membranes have been successfully rendered with extreme wettability and applied to oil/water separation in the laboratory. These mesh materials have typically shown good durability, stability as well as reusability, which makes them promising candidates for an ever widening range of practical applications.

Negative magnetodielectric effect in CaCu3Ti4O12

This work was supported by the National Natural Science Foundation of China (Grant No. 11004106) and the National 973 Project (Nos. 2011CB922101 and 2009CB623303).

A facile strategy for the functionalization of boron nitride nanotubes with Pd nanoparticles

A facile in situ fabrication of palladium nanoparticles decorated boron nitride nanotubes (Pd-BNNTs) is described. The decoration of BNNTs was carried out by the self-regulated reduction of palladium chloride (PdCl2) with the aid of sodium dodecyl sulfate (SDS). During the preparation process, the surfactant SDS plays a dual role: it aids the dispersibility of BNNTs and produces the reductant of CH3(CH2)10CH2OH. Then the CH3(CH2)10CH2OH can reduce Pd2+ to form Pd nanoparticles on the surface of BNNSs. The as-prepared Pd-BNNTs were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The results show that the Pd nanocrystalline particles can be deposited onto the BNNTs surface via this simple route. This approach constitutes a basis for the assembly and integration of nanoscale materials onto BNNTs and puts a light on the potential application of the BNNTs in electronic, catalysis, and hydrogen storage fields.