La2O3/ZnO/TiO2光催化降解活性艳红K-2BP的研究

采用溶胶-凝胶法制备了La2O3/ZnO/TiO2复合光催化剂,以紫外灯为光源,活性艳红K-2BP为模型降解物,研究了La2O3/ZnO/TiO2的光催化性能.结果表明:当锌和镧的掺杂量w(zno)=20%,w(La2O3)=0.5%,煅烧温度为500℃时,La2O3/ZnO/TiO2复合光催化剂的光催化活件最高;当催化荆投加量4 g/L,通气量800 mL/min,初始pH值3.12时,La2O3/ZnO/TiO2对活性艳红K-2BP的降解效果最好.实验证明.La2O3/ZnO/TiO2对活性艳红K-2BP的降解遵从Lang-muir-Hinshelwood动力学模型,测得其反应速率常数k=11.5 mg/(L·min);吸附常数K=2.88×10-2L/mg.     

纳米氧化锌、硫酸锌和AM真菌对玉米生长的影响

纳米氧化锌(Zn O)是应用最为广泛但具有一定生物毒性的金属型纳米颗粒(nanoparticles,NPs)之一,而丛枝菌根(arbuscular mycorrhizal,AM)真菌能改善宿主植物矿质营养和增强宿主植物抗逆性,但纳米Zn O和其他锌污染物之间的关系以及AM真菌对其生物效应的影响目前尚不清楚.通过温室盆栽试验,研究了单一或复合施加纳米Zn O、ZnSO_4(500mg·kg~(-1))时接种AM真菌Funneliformis mosseae BEG 167对玉米生长的影响.结果表明,纳米Zn O对AM真菌侵染和玉米植株生长有一定抑制作用,表现出植物毒性,且与同浓度(500 mg·kg~(-1))下的ZnSO_4作用类似.与非菌根对照相比,接种AM真菌降低了玉米植株的Zn含量或Zn吸收量,且在复合处理中对玉米生长表现出较好的促生作用.结果首次表明,纳米ZnO与ZnSO_4在生物毒性上存在复杂的交互作用,而接种AM真菌在二者复合污染时对玉米具有一定的保护作用.     

Eu掺杂ZnO光催化剂降解垃圾渗滤液实验研究

以醋酸锌(Zn(CH3COO)2)、六水合硝酸铕(Eu(NO3)3·6H2O)、氢氧化钠(Na OH)、聚乙二醇(PEG2000)、柠檬酸为主要原料,采用水热法制备Eu掺杂Zn O复合纳米棒光催化材料粉体。用制备的粉体对城市垃圾渗滤液进行光催化降解实验,研究了反应温度、反应时间、光照条件、掺杂比对其光催化氧化效果的影响,用XRD、TEM、EDS等测试手段对粉体进行了表征。研究结果表明,水热反应温度160℃,时间为6 h,制备的3%Eu掺杂Zn O复合纳米棒的光催化效果较好,在365 nm紫外灯照射下,150 min后垃圾渗滤液的脱色率达40%,COD降解率达62%。     

Physiological and antioxidative response of Brassica nigra (L.) to ZnO nanoparticles grown in culture media and soil

Abstract

To investigate metal nanoparticle-induced phytotoxicity, Brassica nigra seeds were exposed to 50–1000?mg L^?1 ZnO nanoparticles in culture media and 100–1000?mg kg^?1 in soil. Plant length and weight were adversely affected in culture conditions, but with soil the effect was not significant. Determination of the radical-scavenging potential revealed that soil grown plants were less stressed than plants grown on culture medium. The total antioxidant and reducing power potential of soil grown plants were less variable compared to plants grown on culture medium. Total phenolic and flavonoid concentrations varied in plants, which changed with the nanoparticle’s concentrations in medium and soil. High performance liquid chromatography analysis showed that rutin was the major antioxidative molecule that significantly increased in nanoparticles-stressed B. nigra plants.     

Highly efficient reduction of aqueous Cr(VI) with novel ZnO/SnS nanocomposites through the piezoelectric effect

In this work, novel ZnO/SnS nanocomposites were successfully synthesized via a hydrothermal approach, which is developed for piezoelectric catalytic reduction of hexavalent chromium (Cr(VI)) in an aqueous solution. The constructed ZnO/SnS nanocomposites exhibited higher catalytic efficiency for Cr(VI) reduction under a mechanical force (e.g., ultrasonic vibration) compared to pristine ZnO and SnS. In particular, the ZnO/SnS (with 30 wt.% of SnS) heterojunctions revealed an optimal degradation activity among all the prepared samples, which completely removed the Cr(VI) (20 mg/L) solution within 35 min. Moreover, the piezoelectric catalytic activity of ZnO/SnS remained stable after four consecutive cycling experiments. The results of the morphology observations indicated that the SnS nanoparticles adhere to the surface of the ZnO nanorods. The improved piezoelectric catalytic performance of the ZnO/SnS heterojunctions can be attributed to the formation of an intimate interfacial between ZnO and SnS, which effectively inhibits the electron-hole recombination and speeds up the rate of charge transfer. The study reveals a new design of ZnO/SnS heterojunctions as a high-performance and eco-friendly piezoelectric catalyst and provides a promising strategy for addressing environmental problems and energy crises.     

One-step preparation of MoOx/ZnS/ZnO composite and its excellent performance in piezocatalytic degradation of Rhodamine B under ultrasonic vibration

This paper synthesized a new type of ternary piezoelectric catalyst MoO_x/ZnS/ZnO (MZZ)by a one-step method.The catalytic degradation of Rhodamine B (RhB) solution (10μg/g,pH=7.0) shows that the composite catalyst has excellent piezoelectric catalytic activity under ultrasonic vibration (40 k Hz).The piezoelectric degradation rate of the optimal sample reached 0.054 min^-1,which was about 2.5 times that of pure ZnO.X-ray diffraction(XRD),X-ray photoelectron spectroscopy (XPS)...     

微生物菌粉与菌液矿化固结Zn~(2+)的研究与对比

利用碳酸盐矿化菌在底物诱导下的酶化作用,分解产生碳酸根离子,矿化固结环境(土壤水体)当中的游离重金属离子,减少其危险。文章以Zn2+溶液模拟重金属离子污染体系,研究过程中发现,生产的矿化产物主要是ZnO.5(OH)62(CO)3。分别用菌粉和菌液进行微生物矿化试验,对矿化产物进行底物分解率,SEM,XRD,矿化粒径的对比研究。从对比研究结果看,菌粉复活后,可以达到与菌液基本相同的矿化效果。而菌粉相对于菌液而言,其主要优势在于能长时间储存,产品体积小,运输起来更方便,因此,菌粉具有更广泛的应用性。     

Hydrothermal fabrication of selectively doped organic assisted advanced ZnO nanomaterial for solar driven photocatalysis

Hydrothermal fabrication of selectively doped (Ag⁺ + Pd^3 +) advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions (autogeneous; 150°C). Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–Vis spectroscopy and scanning electron microscopy (SEM). The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye, Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.     

全氟辛烷基磺酸钾(PFOS)和纳米氧化锌(Nano-ZnO)复合暴露对斑马鱼下丘脑-垂体-甲状腺轴功能的影响

全氟辛烷基磺酸钾(PFOS)和纳米氧化锌(Nano-Zn O)广泛存在于环境中,但是它们复合暴露对水生生物的潜在毒性机制尚未明确。本文探讨PFOS和Nano-Zn O复合暴露对斑马鱼下丘脑-垂体-甲状腺轴(HPT轴)毒性的影响。将斑马鱼胚胎从孵化开始暴露于PFOS(0.2、0.4、0.8 mg·L~(-1))、Nano-Zn O(6.75、12.5、25 mg·L~(-1))、PFOS+Nano-Zn O(0.2+6.75、0.4+12.5、0.8+25 mg·L~(-1))溶液中15 d后,分析幼鱼的发育毒性,体内的甲状腺激素(甲状腺素(T4)和三碘甲状腺氨酸(T3)含量和与甲状腺有关基因(CRF、TSH、NIS、TG和TPO)的表达情况。结果发现复合暴露组与单独暴露组相比,前者显著诱导了幼鱼的畸形率,降低了幼鱼的存活率,并抑制了幼鱼的体长。复合暴露组显著增加了幼鱼体内T3含量,同时抑制体内T4的含量。与单独暴露组相比,复合暴露组显著诱导了CRF和NIS基因的表达,同时抑制了TSHβ和TG基因的表达。而TPO基因的表达水平在单独和复合暴露组中没有显著差异。本研究首次证明了PFOS和Nano-Zn O复合暴露对斑马鱼幼鱼甲状腺轴的干扰效果并对其进行了机制探讨。     

Cu/盘状ZnO模型催化剂催化CO2加氢反应中生成CO的活性位研究

通过水热法合成盘状ZnO,并在其表面负载Cu得到Cu/盘状ZnO模型催化剂,将不同气氛下(5%CO/Ar、2.5%H_2/2.5%CO/Ar、5%H_2/Ar,分别记为CZ-5CO、CZ-2.5H_2-2.5CO、CZ-5H_2)还原的模型催化剂用于逆水煤气变换反应.对催化剂进行热重分析(TGA)、X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、原位紫外拉曼光谱(in situ UV-Raman)表征.结果表明,不同的还原气氛可得到不同尺寸的Cu颗粒及不同缺陷浓度的Cu-ZnO界面.CO_2程序升温脱附(CO_2-TPD)结果表明,不同的Cu-ZnO界面具有不同的CO_2活化能力.其中CZ-5H_2形成的Cu-ZnO界面对CO_2活化能力最强,表现出最佳的逆水煤气变换反应活性;CZ-5CO具有更多的表面缺陷可能是由于存在Cu_3Zn合金,但Cu-ZnO界面上CO_2的吸附容量降低,导致逆水煤气变换反应活性低;CZ-2.5H_2-2.5CO的活性介于CZ-5H_2与CZ-5CO之间,界面对CO_2的活化量也介于两者之间.