(Phen)2.5HPW/WO3复合空心微球的制备及光催化性能

通过磷钨酸H3PW12O40(HPW)和邻菲啰啉C12H8N2(Phen)的溶液反应,合成了杂多化合物(C12H8N2)2.5H3PW12O40((Phen)2.5HPW),以WO3空心微球为载体,负载杂多化合物(Phen)2.5HPW,制备了(Phen)2.5HPW/WO3复合空心微球.用等离子体原子发射光谱(ICP-AES)、元素分析(EA)、热重-差热分析(TG-DTA)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、紫外-可见漫反射吸收光谱(UV-vis DRS)对样品进行了表征.在高压汞灯照射下,研究了杂多化合物(Phen)2.5HPW、WO3空心微球和(Phen)2.5HPW/WO3复合空心微球对甲基橙水溶液的光催化降解活性,结果表明,(Phen)2.5HPW/WO3复合空心微球的光催化活性高于单独的杂多化合物(Phen)2.5HPW和WO3空心微球,催化剂易于回收,光催化性能稳定.     

磷钨酸和邻菲哕啉杂多化合物的合成及光催化性能

通过磷钨酸(H3 PW12O40·xH2O)和邻菲罗啉(C12H8N2·H2O)的溶液反应合成了Keggin结构杂多化合物(C12H8N2)2.5·H3PW12O40,用电感耦合等离子体原子发射光谱(ICP-AES)、元素分析(EA)、热重-差热分析(TG-DTA)、傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD...     

磷钨酸钾模板法制备高活性二氧化钛空心微球（英文）

TiO2空心微球因具有低密度、高活性、易分离而有利于多次重复使用的优点而广受关注.本文介绍一种无氟制备TiO2空心微球的简单方法——磷钨酸钾(K3PW12O40)模板法.首先,将H3PW12O40和KCl溶液混匀,得到白色牛奶状的K3PW12O40模板(式(1)),然后在磁力搅拌下加入一定量的Ti(SO4)2粉末,加热至大约125 oC开始回流.回流8 h后,过滤洗涤.滤饼分散在强NaO H溶液中,原位除去K3PW12O40模板(式(2)).最后,将催化剂洗涤到滤液为中性,干燥后即得到TiO2空心微球.3KCl+H3PW12O40=K3PW12O40↓+3HCl(1)K3PW12O40+24Na OH=12Na2WO4+K3PO4+12 H2O(2)Ti(SO4)2+2H2O=Ti O2+2H2SO4(3)我们将所制备的Ti O2空心微球,采用X射线衍射、透射电子显微镜、扫描电子显微镜、傅立叶红外光谱、固体粉末漫反射和X射线光电子能谱等进行了表征.采用紫外光催化降解阴离子染料(活性嫣红X3B)来评价催化剂的性能.实验结果显示:(1)所制Ti O2空心微球直径在0.5–1.0μm;(2)磷钨酸钾模板剂充当晶核,有利于空心微球的晶化;(3)加入的高浓度硫酸钛,水解产生大量的硫酸,抑制硫酸钛水解,不利于Ti O2空心微球的晶化(式(3));(4)催化剂的活性随着硫酸钛量的增加而先增后降.4 mmol硫酸钛用量的Ti O2空心微球具有最高的光催化活性,是Ti O2颗粒样品(无磷钨酸钾模板法制备)的2.1倍.用该方法制备的Ti O2空心微球活性高可归因于以下主要原因:(1)Ti O2空心微球独特的孔结构;(2)良好的晶化程度(TiO2样品晶化度越高,越有利于光生载流子的分离,抑制复合);(3)样品残余磷钨酸钾模板和Ti O2之间存在光生电子转移,有利于空心微球Ti O2活性的提高.该法具有操作简单、重复性好、易于批量制备的等优点,有望广泛应用于(光)催化、电化学、分离与纯化以及药物缓释等领域.     

磷钨酸钾模板法制备高活性二氧化钛空心微球

TiO2空心微球因具有低密度、高活性、易分离而有利于多次重复使用的优点而广受关注.本文介绍一种无氟制备TiO2空心微球的简单方法——磷钨酸钾(K3PW12O40)模板法.首先,将H3PW12O40和KCl溶液混匀,得到白色牛奶状的K3PW12O40模板(式(1)),然后在磁力搅拌下加入一定量的Ti(SO4)2粉末,加热至大约125oC开始回流.回流8 h后,过滤洗涤.滤饼分散在强NaOH溶液中,原位除去K3PW12O40模板(式(2)).最后,将催化剂洗涤到滤液为中性,干燥后即得到TiO2空心微球.3KCl + H3PW12O40= K3PW12O40ˉ+3HCl (1) K3PW12O40+24NaOH =12Na2WO4+ K3PO4+12 H2O (2) Ti(SO4)2+2H2O = TiO2+2H2SO4(3)我们将所制备的TiO2空心微球,采用X射线衍射、透射电子显微镜、扫描电子显微镜、傅立叶红外光谱、固体粉末漫反射和X射线光电子能谱等进行了表征.采用紫外光催化降解阴离子染料(活性嫣红X3B)来评价催化剂的性能.实验结果显示：(1)所制TiO2空心微球直径在0.5–1.0μm;(2)磷钨酸钾模板剂充当晶核,有利于空心微球的晶化;(3)加入的高浓度硫酸钛,水解产生大量的硫酸,抑制硫酸钛水解,不利于TiO2空心微球的晶化(式(3));(4)催化剂的活性随着硫酸钛量的增加而先增后降.4 mmol硫酸钛用量的TiO2空心微球具有最高的光催化活性,是TiO2颗粒样品(无磷钨酸钾模板法制备)的2.1倍.用该方法制备的TiO2空心微球活性高可归因于以下主要原因：(1)TiO2空心微球独特的孔结构;(2)良好的晶化程度(TiO2样品晶化度越高,越有利于光生载流子的分离,抑制复合);(3)样品残余磷钨酸钾模板和TiO2之间存在光生电子转移,有利于空心微球TiO2活性的提高.该法具有操作简单、重复性好、易于批量制备的等优点,有望广泛应用于(光)催化、电化学、分离与纯化以及药物缓释等领域.     

基于Keggin阴离子链镍化合物的结构和质子导电性

由H+(H2O)2.5阳离子,[Ni(H2O)8]2+阳离子,[PW12O40]3-阴离子和异烟酸氮氧化物(HINO)自组装成一个具有质子导电性的化合物{[Ni(H2O)8][H(H2O)2.5](HINO)4(PW12O40)}n。293 K的单晶X-射线衍射分析表明标题化合物形成1个带有一维通道的三维氢键网络结构。[PW12O40]3-阴离子填充在一维通道内并且自组装成多阴离子链。热重分析表明在20~100℃范围内化合物没有失重,表明化合物结构单元内所有的水分子在100℃以下不易失去。标题化合物在85~100℃范围内表现出好的离子导电性(1×10-3~2×10-3S.cm-1)。     

第四周期过渡金属钨磷杂多酸盐的合成及表征(C)

合成了Keggin型缺位取代杂多酸盐(Na5PW11Z(H2O)O39,Z=Mn、Fe、Co、Ni、Cu、Zn,以下简称PW11Z)催化剂.通过ICP、IR、UV等表征手段对催化剂进行了表征.元素分析结果表明,各缺位取代杂多酸盐的计量式为Na5PW11Z(H2O)O39.IR光谱表明,取代型杂多化合物仍保持Keggin型骨架结构.而且,除了Na5PW11Ni(H2O)O39以外,其余化合物的P-O键吸收峰发生劈裂,其劈裂强度为PW11Cu>PW11Zn>PW11Mn>PW11Fe>PW11Co.Mo=O键的振动向低波数位移.UV表征结果表明,由于过渡金属的引入,相对于Keggin型杂多酸H3PW12O40,取代产物的紫外可见吸收峰向紫外方向位移,但位移强度不大,基本有与H3PW12O40中Mo=O键的ππ*跃迁大致相同的吸收.还利用以上催化剂对正己醇氧化生成正己醛的反应活性进行了考察.     

（4，4＇-bipyH）3[PW12O40]（4，4＇-bipy）·7H2O的水热合成、晶体结构与热性质

用中温水热技术合成了(4,4'-bipyH)3[PW12O40](4,4'-bipy)·7H2O,用元素分析、X射线单晶衍射、IR、UV-vis和TG-DTA 对其进行了表征.结果表明,化合物的晶体属单斜晶系,P2(1)/c空间群.标题化合物是由3个质子化的4,4'-bipy分子、一个Keggin结构的钨磷杂多阴离子[PW12O40]3-和一个4,4'-bipy分子及7个结晶水分子所组成.钨磷杂多阴离子与质子化的联吡啶及结晶水分子之间通过氢键作用,连接成无限二维层状结构,形成超分子化合物.     

基于1,10-邻菲罗啉-5,6-二酮和Keggin型多金属氧化物的化合物的水热合成及性质(英文)

在水热条件下,用1,10-邻菲罗啉-5,6-二酮(Do)作为中性配体合成了3个基于Keggin型多金属氧化物的化合物(HDo)6(PW12O40)2·H2O(1),[Cu(Do)2(H2O)]2[Cu(Do)2(PW12O40)(H2O)](PW12O40)(2)和[Pb(Do)2(PW12O40)](HDo)(3),并对其进行了元素分析、红外光谱、电感耦合等离子体分析、X射线光电子能谱、热重分析以及荧光光谱等表征。单晶X射线衍射分析表明化合物1和2为零维结构,化合物3是一维链状结构。     

(4,4′-bipy H)_3[PW_12O_(40)](4,4′-bipy)·7H_2O的水热合成、晶体结构与热性质

用中温水热技术合成了(4,4′-bipyH)3[PW12O40](4,4′-bipy).7 H2O,用元素分析、X射线单晶衍射、IR、UV-vis和TG-DTA对其进行了表征.结果表明,化合物的晶体属单斜晶系,P2(1)/c空间群.标题化合物是由3个质子化的4,4′-bipy分子、一个Keggin结构的钨磷杂多阴离子[PW12O40]3-和一个4,4′-bipy分子及7个结晶水分子所组成.钨磷杂多阴离子与质子化的联吡啶及结晶水分子之间通过氢键作用,连接成无限二维层状结构,形成超分子化合物.     

[Nd(ONO2)6][Cu(Im)(Phen)2]2(OH)·4H2O的合成、晶体结构及磁性质

用Nd(NO3)3·6H2O、Im(C3H4N2)、Phen(C12H8N2)和Cu(NO3)2·3H2O为原料,两步反应合成了标题化合物.该化合物晶体属P1空间群,晶胞参数a=1.012 6(2) nm,b=1.179 2(2)nm,c=1.398 5 nm,α=111.32(3)°,β=93.17(3)°,γ=90.33(3)°,Z=1,R=0.043.测定了化合物的UV-Vis-NIR及IR光谱和变温磁化率,发现标题化合物在低温下具有反铁磁性质.     

A templated method to Bi2WO6 hollow microspheres and their conversion to double-shell Bi2O3/Bi2WO6 hollow microspheres with improved photocatalytic performance

Bi(2)WO(6) hollow microspheres with dimension of ca. 1.5 μm were synthesized via a hydrothermal method using polystyrene particles as the template. The as-prepared Bi(2)WO(6) hollow microspheres can be further transformed to double-shell Bi(2)O(3)/Bi(2)WO(6) hollow microspheres. The samples were fully characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, N(2)-sorption Brunauer-Emmett-Teller surface area, UV-vis diffuse-reflectance spectroscopy, and X-ray photoelectron spectroscopy. The as-formed double-shell Bi(2)O(3)/Bi(2)WO(6) hollow microspheres exhibit enhanced photocatalytic activity due to the hollow nature and formation of the p-n junction between p-type Bi(2)O(3) and n-type Bi(2)WO(6). The study provides a general and effective method in the fabrication of composition and dimension-tunable composite hollow microspheres with sound heterojunctions that may show a variety of applications.     

Enhanced oxygen reduction at Pd catalytic nanoparticles dispersed onto heteropolytungstate-assembled poly(diallyldimethylammonium)-functionalized carbon nanotubes

Both Keggin-type phosphotungstic acid (HPW) and Pd are not prominent catalysts towards the oxygen reduction (ORR), but their composite Pd-HPW catalyst produces a significantly higher electrochemical activity for the ORR in acidic media. The novel composite catalyst was synthesized by self-assembly of HPW on multi-walled carbon nanotubes (MWCNTs) via the electrostatic attraction between negatively charged HPW and positively charged poly(diallyldimethylammonium (PDDA)-wrapped MWCNTs, followed by dispersion of Pd nanoparticles onto the HPW-PDDA-MWCNT assembly. The as-prepared catalyst was characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). TEM images show that Pd nanoparticles were uniformly dispersed on the surface of MWCNTs even when the Pd loading was increased to 60 wt%. Electrochemical activity of the catalysts for the ORR was evaluated by steady state polarization measurements using a rotating disk electrode. Compared with the acid treated MWCNTs, Pd nanoparticles supported on the HPW-assembled MWCNTs show a much higher ORR activity that is comparable to conventional Pt/C catalysts. The high electrocatalytic activities could be related to high dispersion of Pd nanoparticles as well as synergistic effects originating from the high proton conductivity of HPW. The Pd/HPW-PDDA-MWCNTs system as the cathode catalyst in proton exchange membrane fuel cells is demonstrated.     

Sulfonated poly(ether ether ketone) composite membranes based on amino-modified halloysite nanotubes that effectively immobilize phosphotungstic acid

In this work, we prepared amino-modified halloysite nanotubes (PEI-DHNTs) via the co-deposition of self-polymerized dopamine and polyethylenimine (PEI) on the surface of nanotubes, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). A series of composite proton exchange membranes (PEMs) were prepared by incorporating PEI-DHNTs and phosphotungstic acid (HPW) into sulfonated poly(ether ether ketone) (SPEEK). It was found that both PEI-DHNTs and HPW were well dispersed in the polymer matrix, exhibiting excellent filler-matrix compatibility. The composite membranes demonstrated enhanced proton conductivity, reaching as high as 0.078 S cm⁻¹ with 33.3 wt.% HPW loading, which was ~90% higher than that of SPEEK control membrane. Such improvement was mainly attributed to the strong acid–base pairs formed by PEI-DHNT with both SPEEK and HPW, which shortened proton hopping distance and created more continuous proton conduction pathways. Furthermore, the membrane conductivity remained almost constant after 1 year's immersion in liquid water, indicating the successful immobilization of HPW in the composite membranes.     

固体酸催化合成蓖麻基癸二酸二辛酯的研究

以蠕虫(Worm-like)状介孔材料为载体,采用浸渍的方法将磷钨酸负载到介孔载体上制备不同磷钨酸负载量的固体酸催化剂.通过X射线衍射(XRD)、红外光谱(FT-IR)和N2吸附-脱附等表征手段对其物理化学性质进行分析,结果表明磷钨酸成功地负载于Wormlike介孔材料上.将一系列负载型磷钨酸催化剂用于癸二酸二辛酯的合成反应中,考察其酸催化活性,并对磷钨酸负载量、癸二酸和异辛醇物质的量比、反应温度以及反应时间等因素对酯化率的影响进行了研究.实验结果表明:当反应控制温度在120℃、癸二酸与异辛醇物质的量比为1∶3、反应时间为3h、磷钨酸负载量为50%时,反应酯化率可达98.2%.     

A novel ternary GO@SiO2‐HPW nanocomposite as an efficient heterogeneous catalyst for the synthesis of benzazoles in aqueous media

A new solid acid catalyst, consisting of 12‐phosphotungstic heteropoly acid (HPW) supported on graphene oxide/silica nanocomposite (GO@SiO₂), has been developed via immobilizing HPW onto an amine‐functionalized GO/SiO₂ surface through coordination interaction (GO@SiO₂‐HPW). The GO@SiO₂‐HPW nanocomposite was characterized by Fourier transform infrared (FT‐IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and powder X‐ray diffraction (XRD). The prepared nanocomposite could be dispersed homogeneously in water and further used as a heterogeneous, reusable, and efficient catalyst for the synthesis of benzimidazoles and benzothiazoles by the reaction of 1,2‐phenelynediamine or 2‐aminothiophenol with different aldehydes.     

Photocatalytic Degradation of Imidacloprid by Phosphotungstic Acid Supported on a Mesoporous Sieve MCM‐41

Solid catalysts consisting of polyoxometalates (POM) namely phosphotungstic acid H₃PW₁₂O₄₀ (HPW) supported on a mesoporous sieve MCM‐41 have been prepared and characterized by FT‐IR, X‐ray diffraction, nitrogen adsorption and high resolution transmission electron microscope (HRTEM). The HPW/MCM‐41 with different HPW loadings from 10 to 60 wt% possess large specific surface area and rather uniform mesopores. Keggin structure of HPW retains on the prepared composite catalysts. The photocatalytic performance of HPW/MCM‐41 was examined by degradation of a durable pesticide imidacloprid. It is found that the prepared photocatalysts exhibit high activity under irradiation of 365 nm monochromatic light. For 50 mL of imidacloprid (10 mg/L), conversion of imidacloprid using 20 mg of HPW/MCM‐41 with 50 wt% loading level and calcined at 300°C reaches 58.0% after 5 h irradiation.     

Silicon dioxide hollow microspheres with porous composite structure: synthesis and characterization

In this paper, a strategy for hollow porous silica microspheres with ideally flower structure is presented. SiO(2)/PAM hybrid composite microspheres with porous were synthesized by the reaction that the porous polyacrylamide (PAM) micro-gels immersed in tetraethoxysilane (TEOS) anhydrous alcohol solution and water in a moist atmosphere, with ammonium hydroxide as a catalyst. The SiO(2) hollow microspheres with porous were obtained after calcination of the composite microspheres at 550 °C for 4 h. The morphology, composition, and crystalline structure of the microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FI-IR), and X-ray diffraction (XRD), N(2) absorption analysis, respectively. The results indicated that the obtained hollow porous SiO(2) microspheres were a perfect flower structure.     

Chelating ligand-mediated synthesis of hollow ZnS microspheres and its optical properties

Monodispersed hollow ZnS microspheres have been successfully synthesized by a facile ethylenediamine tetraacetic acid (EDTA) mediated hydrothermal route. The sizes of the hollow spheres vary from 1.5 to 3.5 microm when the reaction temperature varied from 130 to 230 degrees C. The formation of these hollow spheres is attributed to the oriented aggregation of ZnS nanocrystals around the gas-liquid interface between H(2)S and water. EDTA plays important role as chelating ligand and capping reagent, which regulates the release of Zn(2+) ions for the formation of ZnS hollow spheres. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy, photoluminescence, and Raman spectroscopy. The obtained ZnS hollow spheres show a sharp and photostable UV emission approximately 370 nm, which is attributed to the recombination process associated with interstitial sulfur vacancy.     

Controlled synthesis of olive-shaped Bi2S3/BiVO4 microspheres through a limited chemical conversion route and enhanced visible-light-responding photocatalytic activity

Well-defined olive-shaped Bi(2)S(3)/BiVO(4) microspheres were synthesized through a limited chemical conversion route (LCCR), where olive-shaped BiVO(4) microspheres and thioacetamide (TAA) were used as precursors and sulfur source, respectively. The as-synthesized products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission microscope (HRTEM), X-ray photoelectron spectra (XPS), UV-visible diffuse-reflectance spectroscopy (UV-vis DRS), and photoluminescence (PL) spectra in detail. Compared with pure BiVO(4) microspheres and Bi(2)S(3) nanorods, the Bi(2)S(3)/BiVO(4) products showed obviously enhanced photocatalytic activity for the degradation of rhodamine B (Rh B) in aqueous solution under visible-light irradiation (λ > 400 nm). In addition, the Bi(2)S(3)/BiVO(4) composite microspheres showed good visible-light-driven photocatalytic activity for the degradation of refractory oxytetracycline (OTC) as well. On the basis of UV-vis DRS, the calculated energy band positions, and PL spectra, the mechanism of enhanced photocatalytic activity of Bi(2)S(3)/BiVO(4) was proposed. The present study provides a new strategy to design composite materials with enhanced photocatalytic performance.