Abstract. A simple and effective strategy is proposed to tune the number of graphene layers by selecting suitable starting graphite, using a chemical exfoliation method. It is found that both the lateral size and the crystallinity of the starting graphite play important roles in the number of graphene layers obtained. Using artificial graphite, flake graphite powder, Kish graphite, and natural…
Abstract. The current–voltage characteristics of individual cup-stacked carbon nanotubes (CSCNTs) were investigated in situ inside the transmission electron microscope. Different from other quasi-1D carbon structures such as multi-walled carbon nanotubes, carbon nanofibers or graphitic fibers that normally behave as a metallic conductor of electrons, individual CSCNTs were found to exhib…
Abstract. Nitrogen doped mesoporous TiO2 was prepared via a modified two-step hydrothermal route. In contrast to undoped mesoporous TiO2, nitrogen doped mesoporous TiO2 has superior photocatalytic activity under both UV and visible light irradiation. Photoluminescence spectra reveal that nitrogen doped mesoporous TiO2 possesses abundant surface states, which can play a vital role in trappin…
Abstract. Two series of nitrogen doped TiO2 samples with different ratios of anatase to rutile phases were prepared by milling the mixture of P25 TiO2 and C6H12N4 in air and gaseous NH3 atmosphere, respectively. Compared to air, NH3 atmosphere plays an important role in delaying the crystallite transformation from anatase to rutile in the mechanochemical reaction of TiO2 and C6H12N4. In con…
Extraordinary and stable long wavelength emission centered at 685 nm from the yard-glass shaped boron nitride nanotubes YG-BNNTs was observed in their cathodoluminescence and photoluminescence spectroscopy. The mechanism for this near-red light emission at 685 nm is attributed to the periodical nature of the BNNT units with regular lattice defects. The visible-light emission from YG-B…