Extended light absorption and dynamic charge separation are vital factors that determine the effectiveness of photocatalysts. In this study, a nonmetallic plasmonic S-scheme photocatalyst was fabricated by loading 1D plasmonic W 18 O 49 nanowires onto 2D g-C 3 N 4 nanosheets . W 18 O 49 nanowires play the dual role of a light absorption antenna—that extends light adsorption—and a hot electron donor—that assists the water reduction reaction in a wider light spectrum range. Moreover, S-scheme charge transfer resulting from the matching bandgaps of W 18 O 49 and g-C 3 N 4 can lead to strong redox capability and high migration speed of the photoinduced charges. Consequently, in this study, W 18 O 49 /g-C 3 N 4 hybrids exhibited higher photocatalytic H 2 generation than that of pristine g-C 3 N 4 under light irradiation of 420–550 nm. Furthermore, the H 2 production rate of the best-performing W 18 O 49 /g-C 3 N 4 hybrid was 41.5 μmol·g −1 ·h −1 upon exposure to monochromatic light at 550 nm, whereas pure g-C 3 N 4 showed negligible activity. This study promotes novel and environmentally friendly hot-electron-assisted S-scheme photocatalysts for the broad-spectrum utilization of solar light.
Yan Wei,Xuehui Zhang,Yu Song,Bing Han,Xiaoyang Hu,Xinzhi Wang,Yuanhua Lin,Xuliang Deng
In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. The aim of this study is to develop magnetic biodegradable fibrous materials with potential use in bone regeneration. Magnetic biodegradable Fe3O4/chitosan (CS)/poly vinyl alcohol (PVA) nanofibrous membranes were achieved by electrospinning with average fiber diameters ranging from 230 to 380 nm and porosity of 83.9–85.1%. The influences of polymer concentration, applied voltage and Fe3O4 nanoparticles loading on the fabrication of nanofibers were investigated. The polymer concentration of 4.5 wt%, applied voltage of 20 kV and Fe3O4 nanoparticles loading of lower than 5 wt% could produce homogeneous, smooth and continuous Fe3O4/CS/PVA nanofibrous membranes. X-ray diffraction (XRD) data confirmed that the crystalline structure of the Fe3O4, CS and PVA were maintained during electrospinning process. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the Fe3O4 loading up to 5 wt% did not change the functional groups of CS/PVA greatly. Transmission electron microscopy (TEM) showed islets of Fe3O4 nanoparticles evenly distributed in the fibers. Weak ferrimagnetic behaviors of membranes were revealed by vibrating sample magnetometer (VSM) test. Tensile test exhibited Young's modulus of membranes that were gradually enhanced with the increase of Fe3O4 nanoparticles loading, while ultimate tensile stress and ultimate strain were slightly reduced by Fe3O4 nanoparticles loading of 5%. Additionally, MG63 human osteoblast-like cells were seeded on the magnetic nanofibrous membranes to evaluate their bone biocompatibility. Cell growth dynamics according to MTT assay and scanning electron microscopy (SEM) observation exhibited good cell adhesion and proliferation, suggesting that this magnetic biodegradable Fe3O4/CS/PVA nanofibrous membranes can be one of promising biomaterials for facilitation of osteogenesis.
Wei-Zhen WU,Meng-Xia HUANG,Qing-Da HUANG,Cai-Hua LYU,Jia-Ping LAI,Hui SUN
Methylanthranilate (MA) is a kind of spice that is illegally added in the wine in China. The determination of MA in wine is an important part of quality control for wine production. Therefore, it is of great significance to develop a rapid method for detection of prohibited spice in wine. In this work, an inverse opal structural molecularly imprinted photonic hydrogels (MIPHs) membrane was fabricated by merging the advantages of photonic crystal and molecular imprinting techniques. The MIPHs membrane was prepared by using MA as template molecule, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker, followed by a thermal polymerization at 60 °C. Then the inverse opal structural MIPHs membrane was obtained after removing photonic crystal template and imprinted molecules. The MIPHs membrane exhibited a good selectivity property to MA, and it responded to MA within 6 min. The Bragg diffraction peak shift increased with the increase of MA concentration. A linear relationship was found between the Δ λ and the concentration of MA in the range of 0.1–10.0 mM. And the limit of detection in the present work is about 31 μM. Furthermore, a color change of the MIPHs membrane could be observed by naked eyes. Therefore, the smart MIPHs membrane showed great potential in rapid and visual detection of MA in wine.
A visible-light-driven Ag 3 PO 4 catalyst was successfully synthesized by a facile ion-exchange route. The as-synthesized Ag 3 PO 4 was characterized by X-Ray diffraction (XRD), field-emission scanning electron microscopy, N 2 adsorption-desorption, UV-Vis diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy . Under visible light irradiation , the Ag 3 PO 4 catalyst showed excellent photocatalytic activity for rhodamine (RhB) degradation, but was poor at degrading methyl orange (MO) because of lower adsorption of MO molecules onto the surface of the Ag 3 PO 4 . The photodegradation of RhB and MO was achieved by holes and O 2 •− radical attack in the Ag 3 PO 4 suspension. The photodegradation of MO over the Ag 3 PO 4 catalyst was greatly enhanced in the presence of RhB owing to greater production of O 2 •− radicals.
Yi-ming Zou,Chang-chun Sun,Shao-wen Li,Miao Bai,Yu-xuan Du,Min Zhang,Fei Xu,Yue Ma
A coaxial anode with a carbon fiber core encapsulated in nanocrystalline FeNiMnO 4 with a nitrogen-doped carbon sheath was prepared using carbon fiber cloth as the core, FeNiMnO 4 nanocrystallite arrays as the first coating layer and nitrogen-doped carbon derived from F127 (a kind of triblock copolymer)-resorcinol-melamine gel as the outer layer. After annealing at 600 °C it was used as the anode material of an all solid flexible lithium ion battery using LiFePO 4 as the cathode material and boron nitride modified polyethylene oxide as the electrolyte. The battery had a large areal capacity of ∼1.40 mAh cm −2 and satisfactory cycling stability under different bending and strain states. Annealing below 600 °C leads to incomplete carbonization of the nitrogen-doped carbon and thus a low electrical conductivity while above 600 °C aggregation of FeNiMnO 4 nanocrystallites and their detachment during cycling are observed under bending and strain.
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