共查询到20条相似文献,搜索用时 171 毫秒
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以硝酸锌、氢氧化钠、硝酸铈为原料,采用沉淀法制备了一系列Ce掺杂的Ce/ZnO分级结构微球。采用X射线衍射仪、场发射扫描电子显微镜、能量色散谱仪和紫外-可见漫反射光谱仪等对样品进行表征。以甲基橙的光催化降解为模拟反应,考察了Ce掺杂量对Ce/ZnO分级结构微球光催化性能的影响。结果表明:Ce/ZnO分级结构微球由ZnO微纳米片相互交错构建而成,Ce的掺杂提高了Ce/ZnO分级结构微球的光催化活性,其中Ce摩尔分数为1.5%的Ce/ZnO对甲基橙的光催化降解效果最好,紫外光照射60min甲基橙降解率为98.3%,循环使用4次,其催化活性未明显下降。 相似文献
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采用溶胶-凝胶法制备了Fe掺杂ZnO/TiO2纳米催化剂粉体,利用多种技术手段对样品的组成、形貌、表面化学态、光学性能等进行表征分析,同时通过降解甲基橙溶液来评价样品的光催化性能.研究结果表明,掺杂Fe能稳定ZnO/TiO2的锐钛矿相,细化催化剂颗粒,并且促进光的吸收带隙红移.Fe-ZnO/TiO2的光催化活性相比Ti... 相似文献
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将水热法制备的ZnS纳米球500℃下保温2h制备出由ZnS、ZnO纳米片组装的多孔微球。利用扫描电子显微镜、X射线衍射仪、透射电子显微镜、紫外-可见近红外分光光度计和紫外-可见分光光度计等对样品的形貌、结构和光学性能进行了表征。以甲基橙(MO)的光催化降解为目标反应,评价其光催化活性。ZnS/ZnO异质结材料的带隙明显窄于ZnO,光催化活性得到提高;经60 min紫外光照射后,ZnS/ZnO异质结催化剂对MO的降解率为76%。最后分析和探讨了异质结催化剂的光催化机理。 相似文献
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纳米ZnO因其优良的特性而在光催化、橡胶、医药和化妆品行业等方面有广泛的应用。采用水热法、直接沉淀法、固相法和溶胶-凝胶法等4种方法制备了纳米ZnO。利用X射线衍射仪对试样进行物相分析,使用jade软件进行数据分析,并计算分析样品的平均粒径,结果显示样品的粒径均小于50nm。使用甲基蓝和甲基橙作为光催化对象进行纳米ZnO的光催化实验,检测不同制备方法对所制纳米ZnO在阳光照射下光催化能力大小的影响,并通过紫外-可见分光光度计测试实验前后试剂的吸光度。结果表明纳米ZnO能催化甲基蓝和甲基橙褪色,且对甲基蓝的脱色效果更为显著。 相似文献
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采用溶胶–凝胶法在常压下经不同温度热处理制备了TiO2/SiO2复合气凝胶光催化剂,利用XRD、TGA和BET等手段对其微观结构进行表征,以甲基橙溶液光催化降解实验评价其光催化性能,研究了热处理温度对TiO2/SiO2复合气凝胶的微观结构及光催化性能影响规律.结果表明:随着热处理温度升高,TiO2/SiO2复合气凝胶中锐钛矿结晶度升高,晶粒尺寸增大,比表面积减小,使TiO2/SiO2复合气凝胶对甲基橙溶液的光催化降解活性呈现先升后降的变化趋势.当热处理温度为700℃左右,紫外光照20 min TiO2/SiO2复合气凝胶对甲基橙溶液的降解率达到95.4%. 相似文献
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将溶胶-凝胶法与水热法相结合制备活性碳纤维(ACF)-Ag-TiO2纳米纤维复合材料,利用扫描电镜、透射电镜、能量色散型X射线光谱仪对ACF-Ag-TiO2纳米纤维复合物的表面形貌及晶型进行表征,并以甲基橙的脱色降解为模式反应,考察样品的光催化性能。结果表明,ACF-Ag-TiO2纳米纤维长度为48μm,直径约为58μm,直径约为550 nm;制备的材料中Ag元素的质量分数为0.5%时,ACF-Ag-TiO2的催化效果最优,光照30 min后对甲基橙的降解率为95%。 相似文献
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采用高分子网络凝胶工艺制备了Fe掺杂的Ag-ZnO系列纳米粉体。通过XRD、SEM、XPS、PL和UV-vis对所制备样品的微结构和光学性质进行了表征,随后以甲基橙和亚甲基蓝为模拟污染物,分别在模拟紫外光和模拟太阳光下对所制备的样品进行光催化测试。结果表明,Fe掺杂后,ZnO晶粒尺寸有所减小,且纳米Ag颗粒的分散性得到改善。样品中的Fe以Fe~(2+)和Fe~(3+)形式共存,随着Fe掺杂浓度的增加,ZnO晶格中的铁离子由+2价向+3价转变,导致PL光谱中蓝光发射峰强度降低。光催化测试结果表明样品Zn_(0.96)Fe_(0.01)Ag_(0.03)O具有最好的光催化活性,结合样品的微结构和光学性质对其光催化机理进行了讨论。 相似文献
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In this present study, Ag-hybridized ZnO was prepared through a powder-sol method first, then Ag/ZnO-AC (activated carbon) composite was synthesized by a adsorption method using Ag/ZnO and AC as precursors. The structure and morphology of as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), Raman spectra, and diffuse reflectance absorption spectra, respectively. The photocatalytic performances of the prepared catalysts were investigated by photocatalystic degradation of methyl orange. The influences of initial pH value, initial dye concentration and the calcination temperature on the photocatalytic activity of the catalysts were investigated and the results were discussed. Comparing with pure ZnO and ZnO-AC, Ag/ZnO-AC composite showed greatly enhanced photocatalytic activity. The results demonstrate that the hybridization of silver, activated carbon and ZnO can significantly improve the photocatalytic activity of ZnO. This work could provide new insights into the fabrication of noble metal/ZnO-carbon based composites and facilitate their application in environmental protection issues. 相似文献
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Preparation of Ag nanoparticles coated tetrapod-like ZnO whisker photocatalysts using photoreduction
Ag/tetrapod-like ZnO whisker (T-ZnOw) photocatalysts with different Ag loadings were synthesized by photoreduction of Ag+ on the surface of T-ZnOw. The chemical composition, morphology and photocatalytic properties of Ag/T-ZnOw photocatalysts were characterized and studied in detail. It is found that metal Ag can exist either as nanoparticles or as agglomerates through varying the Ag/ZnO molar ratio (MR). In photodegradation of methyl orange, enhanced degradation rates are achieved by all Ag/T-ZnOw photocatalysts due to increased separation efficiency of photogenerated electron and hole pairs. Specifically, the photocatalytic activities of Ag/T-ZnOw photocatalysts increase with increasing Ag/ZnO MR from 2.4 to 12%. However, further increasing the Ag/ZnO MR to 14.4% induces the formation of more agglomerates, which can act as recombination centers of photogenerated electron and hole pairs, leading to decreased photocatalytic activity of the photocatalyst. 相似文献
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采用配位均匀共沉淀法制备出ZnO/Ag/CdCO3纳米复合光催化剂,用TEM、XRD、FT-IR、ICP等对产物的形貌、微观结构及组成进行了表征,着重研究了反应物配比及Cd(NO3)2浓度对ZnO/Ag/CdCO3纳米复合光催化剂催化降解甲基橙光催化活性的影响规律,结果表明,n(Zn2+):n(Ag+):n(Cd2+)=21:1.76:1.75,Cd(NO3)2浓度为0.168mol·dm-3时制得的纳米复合光催化剂对甲基橙(MO)的降解率较ZnO/Ag提高51%,ZnO/Ag/CdCO3对MO的光催化降解符合一级反应动力学方程,表观速率常数为1.4551h-1,是ZnO/Ag的7倍。 相似文献
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Chengcheng Liu Zhifeng Liu Yabin Li Zhichao Liu Yun Wang Lei E Jing Ya Nicola Gargiulo Domenico Caputo 《Materials Science and Engineering: B》2012,177(8):570-574
CdS and PbS nanoparticles sensitized ZnO nanorods were synthesized by successive ionic layer adsorption and reaction method. The photocatalytic activity of different structures was evaluated by photocatalytic degeneration yield of methyl orange. Co-sensitization of CdS and PbS nanoparticles on ZnO nanorods showed enhanced photocatalytic activity due to its response at visible light area and the stepwise band gap constructed in ZnO/CdS/PbS nanostructures. 相似文献
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S. Kumaresan K. Vallalperuman S. Sathishkumar 《Journal of Materials Science: Materials in Electronics》2017,28(8):5872-5879
In this report, pure and silver (Ag) doped zinc oxide (ZnO) nanoparticles with various concentrations of silver (5 and 10 wt%) was successfully synthesized by a novel and one step microwave irradiation method. Powder X-ray diffraction results indicates that all of the as-synthesized samples including the highest Ag (10 wt%) doping have a hexagonal wurtzite type structure and average crystalline size was found to be 28, 21 and 16 nm for pure and Ag doped ZnO respectively. Spherical shaped morphology with an average diameter of around 32–13 nm was observed by Transmission electron microscope analysis. UV–Vis spectra revealed that, Ag doped samples exhibits a red shift in the absorption band edge with increasing Ag dopant concentration. The photocatalytic degradation of methyl violet (MV), phenol and rhodamine B (RHB) was investigated by using Ag-ZnO catalyst under UV light irradiation. The result showed that the photocatalytic property was significantly improved by Ag doping. The improved photocatalytic mechanism by Ag doping was also discussed. The samples were further characterized by photoluminescence spectra and Fourier Transform Infrared Spectra (FTIR) analysis. 相似文献
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以六水合硝酸锌、九水合硝酸铁和CO(NH2)2为原料,采用均匀沉淀法并且改变实验条件制备了纯纳米ZnO和纳米Fe/ZnO光催化剂。通过X射线衍射(XRD)和扫描电子显微镜(SEM)对所有样品进行表征,并对部分样品进行了X射线能谱分析仪(EDS)测试。结果显示所有样品均为六方纤锌矿结构。此外,所有样品均由小颗粒聚集在一起而形成了形状、大小各不相同的团聚物或颗粒膜。而且随煅烧温度和Fe掺杂浓度的改变,Fe/ZnO样品的晶粒尺寸和表面形貌也随之变化。以甲基橙溶液作为污染物,在高压汞灯的照射下进行了光降解实验,实验结果表明:Fe掺杂Fe/ZnO样品的光催化性能相较纯纳米ZnO样品得到了改善。当Fe掺杂量为1.5%时Fe/ZnO样品的光催化性能最好;另外,适当煅烧温度也使Fe/ZnO样品的光催化活性得到了提升,其中最适煅烧温度为500℃。无论是Fe的掺杂浓度还是煅烧温度,适当的Fe的掺杂浓度和煅烧温度都有利于改善Fe/ZnO样品光催化剂的性能。 相似文献
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采用水热合成法制备ZnO纳米棒及RGO/ZnO纳米棒复合材料。研究不同含量的RGO对RGO/ZnO纳米棒复合材料光催化活性的影响。采用X射线衍射仪(XRD)、场发射电子显微镜(FESEM)、光电子能谱仪(XPS)及漫反射紫外-可见吸收光谱(UV-Vis)检测手段对RGO/ZnO进行表征。结果显示:RGO与ZnO纳米棒成功复合。加入GO的含量不同,获得的RGO/ZnO样品在可见光区域的吸光度值不同。以甲基橙作为模拟污染物的光催化结果表明,RGO/ZnO复合材料具有高的紫外-可见光光降解效率,加入GO与ZnO的质量比为3%时,样品紫外-可见光光催化性能最佳,120min内甲基橙基本可以完全降解;且在波长大于400nm可见光照射下,RGO/ZnO具有一定的可见光活性,180min内其降解甲基橙效率最大可达26.2%。同时,RGO/ZnO具有较好的光稳定性。 相似文献
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Zhenfei Zhang Yong Li Kefeng Li Kai Chen Yongzhen Yang Xuguang Liu Husheng Jia Bingshe Xu 《Journal of Materials Science》2014,49(5):2347-2354
Flower-like Ag/ZnO heterostructure composites were prepared through a solvothermal method without surfactants or templates. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence (PL) spectroscopy. Results demonstrate that flower-like Ag/ZnO heterostructure composites were composed of wurtzite ZnO flowers coated by face-center-cubic Ag nanoparticles. The growth process of flower-like ZnO crystals was investigated, and a possible growth mechanism was proposed. The photocatalytic activity of the as-prepared flower-like Ag/ZnO samples, pure ZnO samples, and commercial TiO2 (Degussa, P-25) was tested with the photocatalytic degradation of methylene blue. Results show that the Ag/ZnO heterostructures were superior in photocatalytic activity to the pure ZnO samples and the commercial TiO2 (Degussa, P-25), but the mixture of Ag (0.1 wt%) particles and ZnO flowers did not, which implies that the heterostructure promoted the separation of photogenerated electron–hole pairs, enhancing the photocatalytic activity. That was primarily verified by the PL results. 相似文献
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利用无水醋酸锌原位水解生成的纳米ZnO作晶种,通过溶液法制备ZnO纳米阵列,研究反应过程中各因素对ZnO纳米阵列形貌的影响,并对制得的ZnO纳米阵列的光催化活性进行研究。结果表明:采用浸涂方式制备晶种,生长得到的ZnO纳米阵列在衬底表面均匀密集分布;采用喷涂方式制备晶种,生长得到的ZnO纳米阵列存在着较大的空白区域。在晶种前驱体溶液中添加二乙醇胺或甲酰胺,会引起纳米ZnO成核的聚集,不利于制得分布均匀的ZnO纳米阵列。反应溶液pH=6.7时,可得到均匀、密集且取向性良好的ZnO纳米阵列结构。以不锈钢金属网为基底制备的ZnO纳米阵列应用于15mg/L甲基橙的光催化降解,3h即降解完全,且进行连续三次反应后仍表现出良好的光催化活性。 相似文献