The N-doped bismuth tungstate （BizWOt） photocatalysts with high visible light activity were prepared by the hydrothermal method using urea as a nitrogen source. The as-prepared N-doped Bi2WO6 samoles were characterized by X-ray diffraction, scanning electron microscopy, specific surface area, photocurrent analysis, and UV-Vis diffuse re- flectrance spectroscopy. The photocatalytic activity was evaluated by photocatalytic degradation of rhodamine B （RhB） solution under visible light irradiation. The photocatalytic mechanisms were analyzed by active species trapping experi- ments which revealed that the holes were the main active species of N-doped BizWO6 products in aqueous solution under visible light irradiation, rather than .OH and O-. With the assistance of H202, the photocatalytic activity for degradation of RhB could be further improved because H202 reacted with conduction band electrons to generate more hydroxyl radicals. KEY WORDS：
Bolin TangGuohua JiangZhen WeiXia LiXiaohong WangTengteng JiangWenxing ChenJunmin Wan
Mesoporous materials have attracted increasing attention due to their wide application. In this paper, the Na4Ge9020 microspheres were firstly prepared by solvothermal method. Then, the as-prepared Na4Ge9020 microspheres were dispersed into Bi（NO3）3 solution, and the Bi4（GeO4）3 microspheres with mesoporous structure were formed due to the solid-state reaction between bismuth nitrate and Na4Ge9020. The morphology, structure and optical properties were characterized by SEM, EDS, XRD, FITR, BET and UV-Vis diffuse reflectance analysis. The as-prepared products exhibited excellent photocatalytic performance for degradation of reactive brilliant red X-3B under the UV light irradi- ation. A possible photocatalytic mechanism was discussed as well.
分别采用传统静电纺丝装置和自行搭建的离心-静电纺丝装置制备出聚丙烯腈(PAN)纳米初生纤维,并在热空气浴中和一定外力作用下进行牵伸,牵伸后使其伸长至原长的1倍到3倍.通过广角X射线衍射(WAXD)、扫描电子显微镜(SEM)等方法对2种纺丝方法制备的PAN纳米初生纤维及经过热空气浴牵伸后的PAN纳米纤维的晶态结构、取向及形貌等进行了表征.研究表明:(1)离心-静电纺丝效率远高于静电纺丝,可达静电纺丝的120倍(离心-静电纺丝纺丝液流速为2 m L/min,静电纺丝纺丝液流速1 m L/h);(2)无论是离心纺丝还是静电纺丝制得的纳米初生纤维结晶度均很低(离心纺丝为25%,静电纺丝为10.1%),但离心纺丝制得的纳米初生纤维有一定的取向(60.5%),而静电纺丝基本没有;(3)经过热空气浴牵伸后,2种纺丝方式制得的纳米纤维结晶度均有所提高(分别为45.8%和36.2%),取向度也有所提高(分别为72.5%和59.8%),随着牵伸温度的提高和牵伸应力的增大,纤维的平均直径不断减小(离心纺丝由675 nm降至510 nm,静电纺丝由460 nm降至355 nm).纳米纤维在制备过程晶态结构及取向的效果有限,但通过热空气浴牵伸可以使晶态结构及取向得到进一步完善.
A zinc tetraaminophthalocyanine derivative, zinc tetra(methacryloyl moiety)aminophthalocyanine (MeZnAPc) (with a double bond) was synthesized by the reaction between zinc tetraaminophthalocyanine (ZnTAPc) and methacryloyl chloride. Atom transfer radical polymerization (ATRP) was employed as the polymerization technique to obtain a novel pH-responsive poly- meric photosensitizer (PEGIlo-b-P(DPA,rco-MeZnAPcm)) by copolymerizing of methoxypolyethylene glycols (MPEG) (as reducing agent), 2-(isopropylamino)ethyl methacrylate (DPA) and MeZnAPc. This photosensitizer was characterized by UV-vis spectroscopy, FTIR, ~H NMR, etc. The results indicated that the photosensitizer presented the well pH-responsive be- havior around the pH range 6.0-6.5 and the high photoactivity to 1,3-diphenylisobenzofuran (DPBF). The result of photoca- talysis oxidation of L-tryptophan (L-Try) suggested that zinc phthalocyanine could present high photoactivity due to its disper- sivity at pH 5.5 without formation of micelles, and its photoactivity decreased dramatically at pH 7.4 due to wrapping ZnTAPc into the micelles. Therefore, the novel pH-responsive polymeric photosensitizer has better application prospects in the field of photodynamic therapy.
