共查询到20条相似文献,搜索用时 15 毫秒
1.
《Journal of the European Ceramic Society》2019,39(10):3070-3076
Doped ZnO based ceramics were fabricated by using a solid state reaction of ZnO co-doped by TiO2, Al2O3 and MgO and sintered in different atmospheres (Air, N2, N2 + CO). The crystalline structures consist in wurtzite ZnO and a minor spinel phase Zn2TiO4. The electrical conductivity is modulated by the sintering conditions with the highest value (˜105 S m−1) obtained in the reducing atmosphere (N2 + CO). The role of defects and vacancies on the electrical behavior was exhaustively investigated by Raman, electron paramagnetic resonance (EPR) and solid state NMR methods. The paramagnetic centres inferred from EPR studies show a Pauli-like spin susceptibility. Their origin was assigned to shallow donors from interstitial defects (Zni) favored by substitutional Al ions (AlZn). The NMR spectral features with a characteristic 185 ppm line which correlates with the electrical conductivity are presumed to be caused by the Knight shift effect from the conduction electrons and the involved paramagnetic centres. 相似文献
2.
Haijie Sun Yiru Fan Xiangrong Sun Zhihao Chen Huiji Li Zhikun Peng Zhongyi Liu 《International journal of molecular sciences》2021,22(14)
Nano Ru-based catalysts, including monometallic Ru and Ru-Zn nanoparticles, were synthesized via a precipitation method. The prepared catalysts were evaluated on partial hydrogenation of benzene towards cyclohexene generation, during which the effect of reaction modifiers, i.e., ZnSO4, MnSO4, and FeSO4, was investigated. The fresh and the spent catalysts were thoroughly characterized by XRD, TEM, SEM, XPS, XRF, and DFT studies. It was found that Zn2+ or Fe2+ could be adsorbed on the surface of a monometallic Ru catalyst, where a stabilized complex could be formed between the cations and the cyclohexene. This led to an enhancement of catalytic selectivity towards cyclohexene. Furthermore, electron transfer was observed from Zn2+ or Fe2+ to Ru, hindering the catalytic activity towards benzene hydrogenation. In comparison, very few Mn2+ cations were adsorbed on the Ru surface, for which no cyclohexene could be detected. On the other hand, for Ru-Zn catalyst, Zn existed as rodlike ZnO. The added ZnSO4 and FeSO4 could react with ZnO to generate (Zn(OH)2)5(ZnSO4)(H2O) and basic Fe sulfate, respectively. This further benefited the adsorption of Zn2+ or Fe2+, leading to the decrease of catalytic activity towards benzene conversion and the increase of selectivity towards cyclohexene synthesis. When 0.57 mol·L−1 of ZnSO4 was applied, the highest cyclohexene yield of 62.6% was achieved. When MnSO4 was used as a reaction modifier, H2SO4 could be generated in the slurry via its hydrolysis, which reacted with ZnO to form ZnSO4. The selectivity towards cyclohexene formation was then improved by the adsorbed Zn2+. 相似文献
3.
By correlating the results of the NH3-TPD characteristic study and the catalyst activity assay of the W/HZSM-5-based catalysts, we confirmed that the intensity and concentration of the surface B-acid sites have pronounced effects on the catalyst performance for dehydro-aromatization of methane (DHAM). It was found experimentally that, by addition of a proper amount of Mg2+, the strong B-acid sites at the catalyst surface could be effectively eliminated, whereas the addition of a proper amount of Zn2+ or Li+ resulted not only in eliminating most of the strong surface B-acid sites but also in generating a kind of new medium-strong acid sites, mostly B-acid sites, simultaneously. The latter could serve as the catalytically active sites for dehydro-aromatization of methane; on such medium-strong surface B-acid sites, the formation of coke would be also alleviated to a greater extent. By simultaneous addition of Mg2+ and Zn2+, optimized adjustment in surface acidity of the catalyst could be realized. On the other hand, the doping of the Zn2+ or Li+ component to the tungsten oxide matrix would facilitate inhibiting aggregation of the W-containing active species and improving dispersion of the W component at the surface of the catalyst, thus leading to a pronounced decrease in the reduction temperature for the hard-to-be-reduced W6+ species and an increase in quantity of the reducible W6+ species at the reaction temperature for DHAM, as has been evidenced by the results of a H2-TPR study on the reducibility of the Zn2+ (or La3+, Li+, Mn2+)-promoted W/HZSM-5 system. The above two roles that Zn2+ and Li+ as promoters played both contributed to the persistence of high methane conversion and benzene selectivity, and the alleviation of coke deposition, as well as the prolongation of the catalyst lifetime. 相似文献
4.
Ibrahim Morad Xiaofeng Liu Jianrong Qiu 《Journal of the American Ceramic Society》2019,102(10):5843-5852
Monolithic luminescent glass-ceramic is highly desirable for solid-state lighting as it is stable and robust, while in practical light-emitting devices only a thin luminescent layer is used for more efficient excitation and light extraction. In this paper, Mn2+-doped glass and glass-ceramic with the composition of 60SiO2-8Na2O–20ZnO–12Ga2O3 were fabricated by the conventional melt-quenching technique. We observe that the crystallization of α-Zn2SiO4 nanocrystals takes place on the glass surface with controllable thickness after heat treatment. The glass samples show typical red emission peaking at λ = 620 nm that can be ascribed to the spin-forbidden 4T1g(G) → 6A1g(S) transition of Mn2+ (d5) located in the octahedral coordination site of the glass host. After surface crystallization this red emission is retained and a new green emission at 528 nm is observed through the control of the crystallization temperature and duration, thus offering tunable emission characteristics promising for the lighting application. This change in the visible emission is interpreted in terms of the change of coordination state of Mn2+ from octahedral in a glass matrix to tetrahedral in the surface precipitated α-Zn2SiO4 crystals. 相似文献
5.
Phase equilibria of the ZnO–SiO2, Al2O3–SiO2 and ZnO–Al2O3–SiO2 systems at liquidus were characterized at 1340–1740 °C in air. The ZnO–Al2O3 subsolidus phase equilibria were derived from the experiments with the SiO2- and CaO + SiO2-containing slags. High-temperature equilibration on silica or platinum substrates, followed by quenching and direct measurement of Zn, Al, Si and Ca concentrations in the phases with the electron probe X-ray microanalysis (EPMA) was used to accurately characterize the system. Special attention was given to zincite phase that was shown to consist of two separate ranges of compositions: round-shaped low-Al zincite (<2 mol.% AlO1.5) and platy high-Al zincite (4–11 mol.% AlO1.5). A technique was developed for more accurate measurement of the ZnO solubility in the low-ZnO phases (corundum, mullite, tridymite and cristobalite) surrounded by the ZnO-containing slag, using l-line for Zn instead of K-line, avoiding the interference of secondary X-ray fluorescence. Solubility of ZnO was found to be below 0.03 mol.% in corundum and cristobalite, and below 0.3 mol.% in mullite. Present experimental data were used to obtain a self-consistent set of parameters of the thermodynamic models for all phases in this system using FactSage computer package. The modified quasichemical model with two sublattices (Zn2+, Al3+, Si4+) (O2?) was used for the liquid slag phase; the compound energy formalism was used for the spinel (Zn2+,Al3+)[Zn2+,Al3+,Va]2O2-4 and mullite Al3+2(Al3+,Si4+) (O2?,Va)5 phases; the Bragg-Williams formalism was used for the zincite (ZnO, Al2O3); other solid phases (tridymite and cristobalite SiO2, corundum Al2O3, and willemite Zn2SiO4) were described as stoichiometric. Present study is a part of the research program on the characterization of the multicomponent Pb–Zn–Cu–Fe–Ca–Si–O–S–Al–Mg–Cr–As–Sn–Sb–Bi–Ag–Au–Ni system. 相似文献
6.
F. Tzompantzi A. Mantilla F. Bañuelos J. L. Fernández R. Gómez 《Topics in Catalysis》2011,54(1-4):257-263
ZnAl layered double hydroxides (LDHs) with different MII/MIII molar ratio (0.89–3.81) were synthesized by the co-precipitation method and calcinated at 723 K. High specific surface areas (228–155 m2/g) and semiconductor properties (band gap values from 3.32 to 3.07 eV) were obtained. The mixed oxides were reconstructed to the crystalline LDHs (memory effect) after being put in contact with aqueous solutions containing phenol and p-cresol. Using UV light, a maximum in photoactivity as a function of the Zn2+/Al3+ molar ratio was observed. The sample with a Zn2+/Al3+molar ratio of 1.48 photodegrades up to 95% of phenol and p-cresol after 4 and 6 h of irradiation, respectively. These values are lower than that obtained with ZnO and commercial P-25 TiO2 photocatalysts. The results show the applicability of alternative photocatalysts for the degradation of organic pollutant compounds rather than others such as TiO2. 相似文献
7.
Optical and Structural Properties of ZnO and ZnO:Cd Particles Grown by the Hydrothermal Method
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Diego A. Guzmán‐Embús Maria F. Vargas‐Charry Carlos Vargas‐Hernández 《Journal of the American Ceramic Society》2015,98(5):1498-1505
Here, we examine the structural, vibrational, optical, and morphological properties of ZnO particles synthesized by the hydrothermal method, incorporating cadmium at different concentrations through the molar ratio Rm = Cd+2/Zn+2 and a thermal treatment at 500°C. The X‐ray diffraction results demonstrated the high crystallinity of the ZnO compound with a wurtzite‐type hexagonal structure. The Raman scattering spectra demonstrated that the ZnO vibrational modes occur in the region between 200 and 1300 cm?1, which is associated with different vibrational configurations characteristic of the ZnO molecule: E2(Low), E2(M), A1(TO) E1(TO), 2B1(High), E2(High), and TA + LO. The modes that were most affected by the incorporation of Cd2+ were those assigned to 2E2(Low), E2(M), and 2B1(High), and this effect was associated with a greater displacement of Zn2+ ions. The optical study showed a reduction in the band gap and a decrease in the crystalline quality due to the substitution of Cd2+ in the ZnO lattice. Cadmium incorporation affected the morphology of the ZnO:Cd particles, changing the lengths and diameters of the ZnO rods; when the Cd concentration was increased, the ZnO rods shortened, forming coin‐type hexagonal structures. 相似文献
8.
《Ceramics International》2020,46(13):20932-20942
Herein, silica carrier was used as underlying structure to prepare composite material loaded with rare earth element Er and Zn. Rare earth elements can improve antimicrobial effects of ZnO due to their specific electronic structure. Er–ZnO/SiO2 hybrid antibacterial material was prepared through sol-gel method and its structure and morphology were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma emission spectroscopy and Brunauer-Emmett-Teller measurements. E. coli and S. aureus were selected as model bacteria to assess antibacterial activity of prepared hybrid material by plate coating method. Er–ZnO/SiO2 exhibited good antibacterial activity towards E. coli and S. aureus. Increase in Er3+ concentration from 0.12% to 1.10% led to increase in antibacterial performance followed by subsequent decrease. Improving effect of Er relied on the molar ratio of Er doped in ZnO/SiO2 hybrid material. The optimal sample was found to be 0.60%Er–ZnO/SiO2, with antibacterial rates of 93.71% and 70.46% against E. coli and S. aureus, respectively. Antibacterial mechanism was assessed by fluorescence detection of reactive oxygen species. In addition, flame atomic absorption spectrometry was used to measure the amount of released Zn2+. Results also showed that 0.60%Er–ZnO/SiO2 hybrid material generated more reactive oxygen species, released more Zn2+ ions, and had the largest surface area, which improved its antibacterial rate. Thus, Er enhanced antibacterial properties of ZnO/SiO2, providing these composite materials with great potential as antibacterial products. 相似文献
9.
Sion F Olive-Méndez Carlos R Santillán-Rodríguez Ricardo A González-Valenzuela Francisco Espinosa-Maga?a José A Matutes-Aquino 《Nanoscale research letters》2014,9(1):169
In this work, we present the role of vanadium ions (V+5 and V+3), oxygen vacancies (VO), and interstitial zinc (Zni) to the contribution of specific magnetization for a mixture of ZnO-V2O5 nanoparticles (NPs). Samples were obtained by mechanical milling of dry powders and ethanol-assisted milling for 1 h with a fixed atomic ratio V/Zn?=?5% at. For comparison, pure ZnO samples were also prepared. All samples exhibit a room temperature magnetization ranging from 1.18?×?10−3 to 3.5?×?10−3 emu/gr. Pure ZnO powders (1.34?×?10−3 emu/gr) milled with ethanol exhibit slight increase in magnetization attributed to formation of Zni, while dry milled ZnO powders exhibit a decrease of magnetization due to a reduction of VO concentration. For the ZnO-V2O5 system, dry milled and thermally treated samples under reducing atmosphere exhibit a large paramagnetic component associated to the formation of V2O3 and secondary phases containing V+3 ions; at the same time, an increase of VO is observed with an abrupt fall of magnetization to σ?~?0.7?×?10−3 emu/gr due to segregation of V oxides and formation of secondary phases. As mechanical milling is an aggressive synthesis method, high disorder is induced at the surface of the ZnO NPs, including VO and Zni depending on the chemical environment. Thermal treatment restores partially structural order at the surface of the NPs, thus reducing the amount of Zni at the same time that V2O5 NPs segregate reducing the direct contact with the surface of ZnO NPs. Additional samples were milled for longer time up to 24 h to study the effect of milling on the magnetization; 1-h milled samples have the highest magnetizations. Structural characterization was carried out using X-ray diffraction and transmission electron microscopy. Identification of VO and Zni was carried out with Raman spectra, and energy-dispersive X-ray spectroscopy was used to verify that V did not diffuse into ZnO NPs as well to quantify O/Zn ratios. 相似文献
10.
Tengfa Long Shu Yin Kouta Takabatake Peilin Zhnag Tsugio Sato 《Nanoscale research letters》2009,4(3):247-253
ZnO nanorods and nanodisks were synthesized by solution process using zinc chloride as starting material. The morphology of
ZnO crystal changed greatly depending on the concentrations of Zn2+ ion and ethylene glycohol (EG) additive in the solution. The effect of thermal treatment on the morphology was investigated.
Photocatalytic activities of plate-like Zn5(OH)8Cl2 · H2O and rod-like ZnO were characterized. About 18% of 1 ppm NO could be continuously removed by ZnO particles under UV light
irradiation. 相似文献
11.
《Ceramics International》2020,46(1):1-7
Zn1-xFexO nanoparticles with Fe doping content from 0 % to 6 % were fabricated by a facile auto combustion method. SEM, XRD, PL and XPS were carried out to characterize the morphologies, structures, optical properties and surface chemical states of the samples. The photocatalytic properties were also investigated toward Methyl Orange (MO) degradation. It was found that the maximum photocatalytic activity was obtained by 4 % Fe-doped ZnO nanoparticles, which was ascribed to the highest ratio of Fe2+/Fe3+. The experimental results and DFT calculations indicated that Fe could effectively affect the photocatalytic activity of ZnO nanoparticles, dependent on Fe2+/Fe3+ ratio and doping contents. Furthermore, a conceivable mechanism of band gap structure and carrier transfer of Fe2+/Fe3+ co-existed Zn1-xFexO was proposed according to experimental analyses and theory calculations. 相似文献
12.
Co-doping effects of (Al,Ti, Mg) on the microstructure and electrical behavior of ZnO-based ceramics
Qianying Sun Guorong Li Tian Tian Jiangtao Zeng Kunyu Zhao Liaoying Zheng Maud Barré Jens Dittmer Francois Gouttenoire Anthony Rousseau Abdel Hadi Kassiba 《Journal of the American Ceramic Society》2020,103(5):3194-3204
Co-doped ZnO-based ceramics using Al, Ti, and Mg ions in different ratios were synthesized with the objective to investigate the doping effects on the crystalline features, microstructure and the electrical behavior. For Al and Ti doping, a coexistence of crystalline phases was shown with a major wurtzite ZnO structure and secondary spinel phases (ZnAl2O4, Zn2TiO4, or ZnaTibAlcOd), while Mg doping did not alter significantly the structural features of the wurtzite ZnO phase. The electrical behavior induced by Al, Ti, and Mg co-doping in different ratios was investigated using Raman, electron paramagnetic resonance (EPR) and 27Al and 67Zn solid-state nuclear magnetic resonance (NMR). Al doping induces a high electrical conductivity compared to other doping elements. In particular, shallow donors from Zni-AlZn defect structures are inferred from the characteristic NMR signal at about 185 ppm; that is, quite far from the usual oxygen coordinated Al. The Knight shift effect emanating from a highly conducting Al-doped ZnO ceramics was considered as the origin of this observation. Oppositely, as Ti doping leads to the formation of secondary spinel phases, EPR analysis shows a high concentration of Ti3+ ions which limit the electrical conductivity. The correlation between the structural features at the local order, the involved defects and the electrical behavior as function of the doping process are discussed. 相似文献
13.
Adsorption of Mercury(II), Lead(II), Cadmium(II) and Zinc(II) from Aqueous Solutions using Mercapto‐Modified Silica Particles
下载免费PDF全文
![点击此处可从《International Journal of Applied Ceramic Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Aljoša Košak Aleksandra Lobnik Maja Bauman 《International Journal of Applied Ceramic Technology》2015,12(2):461-472
This article presents a novel systematic approach to the fabrication of highly functionalized, silica (SiO2) nanoparticles used for the adsorption of heavy‐metal ions (Hg2+, Pb2+, Cd2+, Zn2+). Almost monodispersed silica (SiO2) nanoparticles with narrow particle size distributions of around 85 ± 5 nm were formed using the Stöber process. The prepared SiO2 nanoparticles were successfully surface‐treated during a one‐step procedure by the covalent attachment of mercaptopropyl groups onto the surfaces of the SiO2 nanoparticles. A FTIR spectra analysis confirmed that the binding of the mercaptosilane molecules onto the surface of the silica nanoparticles mediated the Si–O–Si and –SH vibrations. TEM/EDXS micrographs indicated the almost monodispersed and spherical morphology of the prepared product with strong signals of Si and S, thus implying that the coating procedure involving the mercapto groups onto the silica surface had been successfully accomplished. The final results for the heavy‐metal (Hg2+, Pb2+, Cd2+, Zn2+) adsorption showed the strongest affinity within the following sequence Hg2+ (99.9%) > Pb2+ (55.9%) > Cd2+ (50.2%) > Zn2+ (4%). Adsorption equilibrium was achieved after 1 h for all the analyzed samples. 相似文献
14.
R. Spitzner G. Dill W. Schroth H. Hennig K. M. Jamil 《Advanced Synthesis \u0026amp; Catalysis》1976,318(2):298-312
Preparation and Coordination Behaviour of 2-Acylmethylene-thiazolidines The reaction of 2,2-dichlorovinyl ketones with 2-aminoethanethiol in different solvents is described. The 2-acylmethylene-thiazolidines as the main products from this reaction are studied in view of their coordination tendency to divalent metal ions. The prepared neutral chelates with Cu2+, Ni2+, Co2+, Pd2+, Zn2+ have [N2O2] coordination, elucidated by analytical, spectroscopical and magnetochemical methods. 相似文献
15.
Extremely high corrosion resistance of ZnxNi1–xCr2O4 spinel as sidewalls in the aluminum electrolyte
《Journal of the European Ceramic Society》2023,43(6):2690-2699
The sidewall material is a key component in new electrolytic cell with an inert electrode for the aluminum electrolysis industry. The continuous development of novel sidewall materials with excellent corrosion resistance in molten salts electrolyte is an important topic. Herein, a new system of sidewall material, spinel structured ZnxNi1–xCr2O4 (x = 0 – 1), is prepared by solid-phase reaction and the corrosion-resistance enhancement is investigated. The results prove that Zn2+ plays two roles in the ZnxNi1–xCr2O4 spinels. Firstly, Zn2+ tunes the surface energies of spinels resulting in the octahedral grains, which suppresses the cation diffusion in the corrosion process. Secondly, Zn2+ stabilizes the Cr3+ in the spinels. As a result, the Zn0.5Ni0.5Cr2O4 spinel displays an extremely low corrosion rate ~0.007 cm·a–1 in NaF-KF-AlF3 bath at 800 °C comparing with other sidewall materials. The as-obtained spinel shows great potential as a novel sidewall material for the new electrolytic cell. 相似文献
16.
《Ceramics International》2020,46(5):5960-5967
Uniformly lychee-like ZnO/ZnFe2O4 core-shell hollow microspheres with average size of 2.5 μm were successfully synthesized via one-step solvothermal self-assembly route. The core-shell hollow microspheres possessed mesoporous structure with a pore size of about 8.8 nm and the large specific surface area of approximately 54.0 m2/g. The effect of the Zn2+ concentration on the structure, morphology and gas-sensing property of the as-prepared samples were investigated by a series of testing techniques. The gas-sensing results demonstrated that the sensors based on core-shell ZnO/ZnFe2O4 hollow microspheres showed superior gas-sensing response, rapid response-recovery to low-ppm acetone. These excellent properties might be mainly owing to the unique core-shell structure, the large specific surface area, high concentration of oxygen vacancies and the synergetic effect between ZnO and ZnFe2O4. Hence, this material can be utilized as promising gas-sensing materials in the acetone detection. 相似文献
17.
Antimicrobial properties of ZnO nanomaterials: A review 总被引:1,自引:0,他引:1
《Ceramics International》2017,43(5):3940-3961
Waterborne diseases significantly affect the human health and are responsible for high mortality rates worldwide. Traditional methods of the treatment are now insignificant as maximum bacterial strains have developed multiple antibiotic resistance toward commonly used antibiotic drugs. Recently, ZnO nanostructures, due to their biocompatible nature, have attracted the attention of the scientific community to explore and to understand their cytotoxicity, interactions with biomolecules such as proteins, nucleic acids, fats, cell membranes, tissues, biological fluids, etc., and bio-safety for proper utilization in biomedical applications. Herein, we have reviewed the recent developments for the fabrication of ZnO nanomaterials with variable morphologies, factors influencing the growth, morphology and surface defects, and various laboratory methods to evaluate the antibacterial activities toward Gram-positive as well as Gram-negative bacterial strains. A comparative study is carried out to evaluate the mechanistic approach of ZnO nanomaterials toward Gram-positive as well as Gram-negative bacterial cells. ZnO nanomaterials can interact chemically as well as physically to exhibit antibacterial activities. Chemical interactions of the ZnO nanomaterials with bacterial cells lead to the photo-induced production of reactive oxygenated species (ROS), formation of H2O2, and release of Zn2+ ions. In contrast, the physical interaction can show biocidal effects through cell envelope rupturing, cellular internalization or mechanical damage. Finally, surface activation through amine functionalization of ZnO nanoparticles for better antibacterial effects and cytotoxicity of ZnO nanoparticles toward cancer cells is also reviewed. 相似文献
18.
Sergey Sirotkin Robert Meszaros Lothar Wondraczek 《International Journal of Applied Glass Science》2012,3(1):44-52
We report on chemical stability and corrosion behavior of highly depolymerized sulfophosphate glasses from the system ZnO–Na2O–SO3–P2O5 in aqueous solution, providing data on weight loss, ion release rates, and modifications of surface topology as a function of time, temperature and pH value. Observations seem consistent with the previously developed structural model of chemical heterogeneity, where cations Na+ and Zn2+ cluster selectively in the vicinity of sulfate and phosphate anions, respectively. 相似文献
19.
Pure and Sr2+ doped ZnO crystallites were successfully synthesized via a microwave hydrothermal method using Zn(NO3)2·6H2O and Sr(NO3)2·6H2O as source materials. The phase and microstructure of the as-prepared Zn1−xSrxO crystallites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ultraviolet–visible spectrum (UV–vis) and photochemical reaction instrument were used to analyze the photocatalytic properties of the particles. XRD results show that the diffraction peaks of the as-prepared Zn1−xSrxO crystallites shifted slightly toward lower 2θ angle with the increasing of Sr2+ doping concentration from 0% to 0.3%. The pure ZnO crystallites with lamellar structure are found transforming to a hexagonal columnar morphology with the increase of Sr2+ doping concentration. UV–vis analysis shows that the particles have a higher absorption in UV region with a slightly decreased of optical band (Eg) gap. The photocatalytic activity of Sr2+ doped ZnO crystallites was evaluated by the Rhodamine B (RhB) degradation in aqueous solution under visible-light irradiation. Compared with the pure ZnO particles, the photocatalytic properties of the Sr2+ doped ZnO crystallites are obviously improved. The photocatalysis experiment results demonstrate that the 0.1% Sr2+ doped ZnO exhibits the best photocatalytic activity for the degradation of Rhodamine B. 相似文献
20.
Venkata Manthina Tulsi Patel Alexander G. Agrios 《Journal of the American Ceramic Society》2014,97(4):1028-1034
ZnO nanorods have been studied extensively due to facile synthesis and useful optoelectronic properties for applications in nanoscale devices. In a common two‐step procedure, an ethanolic Zn2+ precursor solution is used to deposit ZnO seed crystals on a substrate, which is then immersed in an aqueous Zn2+ precursor solution to grow the nanorods. Here, a forced hydrolysis technique was employed based on additions of water and heat to the seed precursor solution before depositing the seeds on commercial fluorine‐doped tin oxide (FTO)/glass substrates. ZnO nanorods were then grown from these seeds by chemical bath deposition. Analyses showed that the forced hydrolysis resulted in an increase in seed crystallite size and a decrease in the number of seeds deposited. With increasing seed size, the number density of nanorods decreased, while the length and diameter of each rod increased. These findings offer a simple method for exerting control over the number density of ZnO nanorods that is compatible with the rough FTO surface, unlike other methods that require smoother substrates. 相似文献