Synthesis and characterization of Sb-doped SnO2-（CeO2-TiO2） composite thin films deposited on glass substrates for antistatic electricity and UV-shielding

Sb-doped SnO2(ATO)-(CeO2-TiO2) thin Films were deposited on glass substrates using the mixed solution including CeO2-TiO2 precursor and ATO particles by sol-gel dip coating process.ATO particles were prepared using low-temperature hydrothermal process.The mixed molar ratio of ATO to(CeO2-TiO2) vs the properties of CeO2-TiO2 thin film was investigated.The optical properties of the films were characterized by UV-visible transmission and infrared reflection spectra,the sheet resistance of ATO particles and films were measured by rubber sheeter(MYI-50) and four-point probe(HisuperGroup Inc,SDY-5),the surface morphology and structure of the films were analyzed using 3D Digitale Mikroskop and X-ray diffraction(XRD),respectively.The results showed that the ATO precursor solution lost weight completely at about 500 oC,and the ATO particles was obtained,which indicated the same rutile lattice structure as SnO2.The glass substrates coated with ATO-(CeO2-TiO2) thin films showed better properties in antistatic electricity(104-106 Ω/),shielding UV(almost 100%),visible light transmission(70%) and infrared reflection(>30%).     

CeO2-TiO2/SiO2 Anti-Reflecting and UV-Shielding Double-Functional Films Coated on Glass Substrates Using Sol-Gel Method

CeO₂-TiO₂/SiO₂ double-layered films were coated on glass substrates using sol-gel method. The films, formed using spin-coating process, had two optical properties at the same time, anti-reflection in visible region and ultraviolet rays (UV) shielding. The films could be used as museum windows, commercial high-resolution displays and so on. These films were composed of CeO₂ and TiO₂ with molar ratio of 50 to 50 in the first layer and silica matrix in the 2nd layer. Furthermore, the 2nd layer was composed of porous silica films, which showed a lower refractive index, reducing the reflectance significantly in visible wavelength region. The reflectance of the films in visible region between 400 × 700 nm was lower than 2%, and almost 100% UV was shielded. The surface roughness of the films was observed through an atomic force microscope, a depth composition profile of the double layered film was measured with an X-ray photoelectron spectrometer (XPS).     

Structural, electrical and surface morphological studies of Cd2SnO4 and Mg doped Cd2SnO4 thin films

The technologically important conductive Cadmium stannate (Cd₂SnO₄) and Magnesium doped cadmium stannate (Cd₂SnO₄: Mg) thin films were prepared using Cadmium acetate and stannous chloride by spray pyrolysis technique. Films prepared are crystalline and have cubic CdO phase with SnO₂. The X-ray diffraction patterns of both thin films shows perfect crystalline structure and from the data, the particle diameter of both films were calculated. Atomic Force Microscopy (AFM) of both films reveals the uniform thickness of the films and the presence of uniform grain growth in Cd₂SnO₄ and Mg doped Cd₂SnO₄ thin films. Thickness of Cadmium stannate film is 725nm and that of Magnesium doped Cadmium stannate film is 285nm. The indirect band gap energy of Cd₂SnO₄ film is 2.71eV and for magnesium doped Cd₂SnO₄ is 2.97eV were observed from the UV-Visible absorption spectrum studies. Presence of uniform grain growth is found in both thin films. The doping of Magnesium in Cadmium stannate film improves the electrical properties without affecting its structural properties.     

Structure and chemical states of highly eptiaxial CeO2（001） films grown on SrTiO_3 substrate by laser molecular beam epitaxy

Highly epitaxial and pure（001）-oriented CeO2 films were grown on SrTiO3（001） substrates by laser molecular beam epitaxy method without any gas ambient.Layer-by-layer epitaxial growth mode of CeO2 was confirmed by in situ reflection high-energy electron diffraction（RHEED） observations.High-resolution X-ray diffraction（HRXRD） and high-resolution transmission electron microscopy（HRTEM） results indicated the STO（100）//CeO2（100）,STO[100]//CeO2 [110] epitaxial relationship for out-of-plane and in-plane,respectively.The formation mechanism of the epitaxial film was also discussed in the light of a theoretical model.Chemical states of the LMBE ceria films were evaluated and evidences for the existence of Ce3＋and oxygen vacancies were presented.     

Thermal stability of CeO<Subscript>2</Subscript>/ZrO<Subscript>2</Subscript> multilayer thin films prepared by pulsed laser deposition

Multilayers of CeO₂/ZrO₂ thin films were deposited on Si (100) substrates using pulsed laser deposition at an optimized oxygen partial pressure of 3×10⁻² mbar and at room temperature. The CeO₂ layer thickness was 10 nm, while the ZrO₂ layer thickness was varied as 10, 20 and 30 nm. CeO₂ and ZrO₂ layers were deposited alternately to obtain 25 bilayers. High temperature x-ray diffraction (HTXRD) results showed that the multilayer films had cubic ceria and tetragonal ZrO₂. Thermal expansion coefficients were calculated for CeO₂ and t-ZrO₂ and found to increase with the decrease of ZrO₂ layer thickness. The cross sectional transmission electron microscopy (XTEM) of CeO₂/ZrO₂ multilayer also indicated that ceria was found to be in cubic phase while zirconia contained predominantly tetragonal phase along with cubic phase in thermally annealed specimen.     

Characterization and electrochemical performance of CeO2 and Eu-doped CeO2 films as a manganese redox flow battery component

Hexagonal CeO_2 and Eu-doped CeO_2 nanoparticles were obtained using a facile microwave-hydro thermal method under mild conditions and their application towards manganese redox flow battery component were studied. The structural properties were studied by X-ray diffraction and indicate that samples present a fluorite structure. Raman spectroscopy shows Eu3+ ions substitute Ce~(4+) and generate oxygen vacancies. Electrochemical properties of pure and Eu-doped CeO_2 films deposited at graphite substrates investigated by cyclic voltammetry and galvanostatic charge—discharge indicate that dopant concentration affects the electrochemical properties of CeO_2. The increase in the reversibility redox of electrochemical systems observed is attributed to coexistence of Ce~(4+)/Ce~(3+) redox couple confirmed by XPS.Charge—discharge tests display coulombic and voltage efficiency values of above 80% and 90%, respectively. The obtained specific capacity for Ce_(0.99)Eu_(0.01)O_2(372.49 mAh/g) and pure oxide(334.84 mAh/g)indicates that both samples are promising for application in Mn-batteries.     

Promoting effect of microwave irradiation on CeO_2-TiO_2 catalyst for selective catalytic reduction of NO by NH_3

In this work we prepared several CeO₂-TiO₂ catalysts for the NH₃-SCR reactionusing co-precipitation with assistance of microwave irradiation. The catalytic NH₃-SCR activities over CeO₂-TiO₂ catalysts at low temperatures are largely enhanced by the treatment of microwave irradiation, the operation temperature window is also broadened. For better understanding the promotion mechanism, the catalyst prepared by conventional co-precipitation with and without microwave irradiation treatment was characterized with H₂-TPR, NH₃-TPD, XPS, XRD and BET. Microwave irradiation treatment accelerates the crystallite rate of CeO₂-TiO₂ catalysts, and greatly enlarges their surface area by adjusting their microstructures. The resistance to SO₂ and H₂O is also improved via regulating the hierarchical pore structure by the microwave irradiation. Microwave irradiation treatment can also improve the redox property and increase the acid sites over the catalyst surfaces. The result of in situ DRIFTS suggests that the microwave irradiation treatment generates more Brønsted acid sites on CeO₂-TiO₂-2 h catalyst, helpful in SCR reactions. XPS results show that after microwave irradiation on the CeO₂-TiO₂ catalysts, the surface demonstrates an elevated concentration of chemisorbed oxygen, consequently leading to better oxidation of NO to NO₂. Additionally, the molar ratio of Ce³⁺/Ce⁴⁺ has been elevated after being treated by microwave irradiation, a vital factor in enhancing the NH₃-SCR activities.     

The growth and structure of thin oxide films on cerium ion-implanted nickel

Cerium ions were implanted into a high purity polycrystalline Ni to a dose of 2 × 10¹⁶ Ce⁺/cm². The radiation damage and distribution of Ce in Ni substrate were modified by postimplantation vacuum annealing. The Ce implants significantly decreased the NiO growth rate at 973 K. Thin oxide films formed on implanted Ni were composed of three well-defined sublayers, each with an essentially different microstructure. Cerium was present in the near surface region of the oxide in the form of CeO₂ particles, randomly distributed in NiO matrix, and Ce ion segregants at NiO grain boundaries. The size of CeO₂ particles, formed during the initial stages of exposure to oxygen, affected the inhibition of oxide growth. Vacuum annealing following implantation decreased the beneficial effect of Ce implants by increasing the size of CeO₂ particles. The role of Ce implants in inhibiting grain boundary diffusion in NiO is analyzed. As a result of this study, the growth mechanism of thin NiO films on Ce-implanted Ni is proposed.     

Photoluminescent properties of Ca2Gd8（SiO4）6O2： Dy^3＋ phosphor films prepared by sol-gel process

There are growing interests on phosphor thin films owing to their potential application in high-resolution devices such as cathode ray tubes and flat panel display devices. The solution-based sol-gel method is one of the most important techniques for the synthesis of various functional coating films. Compounds with the apatite structure are very suitable host lattices for various luminescent ions. Ca2RE8（SiO4）6O2 （ RE=Y, Gd, La ） is a kind of ternary rare-earth-metal silicate with oxyapatite structure, which has been used as host material for the luminescence of various rare earth and mercury-like ions. In this article, Ca2Gd8（SiO4）6O2：Dy^3＋phosphor films were dip-coated on quartz glass substrates through the sol-gel process. X-ray diffraction （XRD）, atomic force microscopy （AFM）, photoluminescence （PL） spectra, as well as lifetimes were used to characterize the resulting films. AFM study revealed that the phosphor films consisted of homogeneous particles. The Dy^3＋ showed its characteristic emission in crystalline phosphor films, i.e., ^4F9/2-^6H15/2 and ^4F9/2-^6H13/2.     

Sol-gel preparation of La-doped bismuth ferrite thin film and its low-temperature ferromagnetic and ferroelectric properties

Bi0.85La0.15FeO3 thin film was prepared on ATO glass substrates by sol-gel technique. The effect of La doping on phase structure, film surface quality, ion valence, and ferroelectric/magnetic properties of Bi0.85La0.15FeO3 film were investigated. La dop-ing suppressed the formation of impurity phases and the transition of Fe3+ to Fe2+ ions at room temperature. Compared with the un-doped BiFeO3, La-doping also increased the average grain size and the film density, which resulted in the decrease of film leakage current density. The remanent polarization and saturation magnetization were enhanced significantly by La doping. The remanent polarization of Bi0.85La0.15FeO3 films gradually decreased while saturation magnetization increased with the decrease of measuring temperature within a range from 50 to 300 K.     

Preparation,characterization and catalytic oxidation property of CeO2/Cu2+- attapulgite (ATP) nanocomposites

Cerium oxide (CeO₂) coated on copper modified attapulgite clay nanocomoposite (CeO₂/Cu²⁺-ATP) was prepared by homogeneous deposition method. The microstructures of the as-prepared CeO₂/Cu²⁺-ATP nanocomposites were characterized by X-ray diffraction (XRD), energy-dispersive spectrometer (EDS) and transmission electron microscopy (TEM). The results indicated that CeO₂ particles with average size of about 5 nm were loaded onto the Cu²⁺-ATP and were widely dispersed. Comparing the catalytic activity of ATP/CeO₂ and CeO₂/Cu²⁺-ATP, the catalytic activity was improved when a small quantity of Cu²⁺ was introduced. The loading amount of CeO₂ and reaction temperature had important effects on decolorization ratio of methyl orange (MO). When the loading amount and reaction temperature were 70% and 338 K, respectively, the decolorization ratio of MO reached over 99%, which showed excellent catalytic activity.     

Preparation of La MnO_3/graphene thin films and their photocatalytic activity

A novel photocatalyst of La MnO3/graphene thin films with the perovskite-type was synthesized by sol-gel process assisted with spin-coating methods on glass substrates.The prepared samples were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Brumauer-Emmett-Teller(BET) surface area analyzer, X-ray photoelectron spectroscopy(XPS) and UV-vis diffuse reflectance spectroscopy.Results showed that after the introduction of graphene, the perovskite structure was unchanged and the size of La MnO3 particles was about 22 nm, which uniformed growth in graphene sheet.Determination of contact angle indicated that the contact angle of glass substrate decreased and the hydrophilicity improved after treating with H2SO4 and APTES.The UV-Vis photocatalytic activity of the photocatalysts was evaluated by the degradation of diamine green B.La MnO3/graphene thin films had better photocatalytic ability than La MnO3 and Ti O2 films.The obtained k was 0.5627 and 0.3441 h–1 corresponding to La MnO3/graphene films and Ti O2 films, respectively.     

Structural,Morphological, Opto-Electrical and Photoluminescence Studies of Nanoplate Structured Zn-Doped Sn<Subscript>2</Subscript>S<Subscript>3</Subscript> Thin Films

Undoped and Zn-doped Sn₂S₃ thin films were fabricated by spray pyrolysis technique on glass substrates kept at 400 °C. All the films exhibited orthorhombic crystal structure with a preferential orientation along the (2 1 1) plane. Nanoplate structures were observed from the SEM images and the presence of Zn in the doped films was confirmed from the EDX spectra. The average optical transmittance of all the films in the visible region was found to be nearly equal to 80 %. Film resistivity initially decreased from 3.27 × 10^?1 to 0.78 × 10^?1 Ω-cm for the Sn₂S₃ thin film doped with 1 wt% Zn concentration and for higher doping concentration it increased. The obtained results showed that the Sn₂S₃ thin film doped with 1 wt% Zn concentration had better physical properties which made them suitable for photovoltaic applications.     

Phase control of magnetron sputtering deposited Gd2O3 thin films as high-κ gate dielectrics

Gd2O3 thin films as high-κ gate dielectrics were deposited directly on Si（001） substrates by magnetron sputtering at a pressure of 1.3 Pa and different temperatures. X-ray diffraction results revealed that all the films grown from 450 to 570 ℃ were crystalline, and the Gd2O3 thin films consisted of a mixture of cubic and monoclinic phases. The growth temperature was a critical parameter for the phase constituents and their relative amount. Low temperature was favorable for the formation of cubic phase while higher temperature gave rise to more monoclinic phase. All the Gd2O3 thin films grown from different temperatures exhibited acceptable electrical properties, such as low leakage current density （JL） of 10-5 A/cm^2 at zero bias with capacitance equivalent SiO2 thickness in the range of 6-13 nm. Through the comparison between films grown at 450 and 570 ℃, the existence of monoclinic phase caused an increase in JL by nearly one order of magnitude and a reduction of effective dielectric constant from 17 to 9.     

Synthesis of CeO_2/fly ash cenospheres composites as novel photocatalysts by modified pyrolysis process

A novel fly ash cenospheres(FACs)-supported CeO2 composite(CeO2/FACs) was successfully synthesized by the modified pyrolysis process.The prepared composites were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS), and diffuse reflection spectra(DRS) techniques.XRD results indicated that the CeO2 film coated on cenospheres was a face-centered cubic structure.SEM images confirmed that the CeO2 film was relatively compact.XPS results showed that Ce was present as both Ce4+ and Ce3+ oxidation states in CeO2 film coated on FACs substrate.The bandgap of the composite was narrower compared with the pure CeO2.The as-prepared material exhibited good photocatalytic activity for the decolorization of methylene blue(MB) under visible light irradiation, and the first-order reaction rate constant(k) of 0.0028 min–1 for CeO2/FACs composite was higher than 0.0015 min–1 of pure CeO2.The fact that they floated on water meant that CeO2/FACs composites were easily recovered from water by filtration after the reaction.The recycling test revealed that the composites were quite stable during the MB photocatalytic decolorization.The CeO2/ FACs catalyst was therefore promising for practical use in the degradation of pollutants or water cleanup.     

Facile Synthesis of Cu2ZnSnS4 Photovoltaic Absorber Thin Films via Sulfurization of Cu2SnS3/ZnS Layers

Copper zinc tin sulfide (Cu₂ZnSnS₄) has been receiving a lot of attention in recent years as a new, alternative absorber for the production of cheap thin film solar cells owing to the high natural abundance of all the constituents, its tunable direct-band-gap energy, and its large optical absorption coefficient. In addition, to overcome the problem of expensive vacuum-based methods, solution-based approaches are being developed for Cu₂ZnSnS₄ deposition. In this study, Cu₂ZnSnS₄ thin films were grown on soda lime glass substrates via the sulfurization of solution grown Cu₂SnS₃/ZnS stacked sulfide layers. A new facile route to overcome the difficulty of depositing Cu₂ZnSnS₄ thin film with a desired stoichiometric composition in a single cation solution has been presented. The influences of deposition cycles of layers on the morphological, compositional, structural, and optical properties of the samples were investigated. It was observed from scanning electron microscopy (SEM) images that the films were continuous and composed of homogenously distributed large grains. Possible chemical formulations of the best samples were predicted to be Cu_1.99Zn_1.25Sn_1.00S_3.76 and Cu_1.97Zn_1.03Sn_1.29S_3.71 via energy-dispersive X-ray spectroscopy (EDXS) results. The X-ray diffraction (XRD) patterns of the samples matched very well with the reference values. The Raman-scattering analysis of the films proved the phase purity of the CZTS samples. The optical absorption coefficient of the films was found to be about 10⁴ cm^?1 based on absorbance spectroscopy. The optical band gaps of the films were estimated to be between 1.36 and 1.50 eV. From these we are able to conclude that CZTS thin films can be effectively obtained via the vacuum-atmosphere sulfurization of Cu₂SnS₃/ZnS stacked sulfide layers.     

What is the Effect of Critical Surface Tension of PbSO3 Thin Film?

This study focuses on the critical surface tension of lead sulfite (PbSO₃) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO₃ thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO₃ thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension.     

Effects of precursor moisture and inert N_2 atmosphere calcinations on structure and properties of alumina modified CeZrLaNd mixed oxides

CeO_2-ZrO_2 mixed oxides are widely used in the three-way catalysts due to their unique reversible oxygen storage and release capacity. Large surface area, high oxygen storage capacity and good thermal stability of cerium zirconium mixed oxides are the key properties for the automotive catalysts so as to meet the strict emission regulations. In this work, alumina modified CeZrLaNd mixed oxides were prepared by a co-precipitation method. The effects of moisture in precursor and inert N2 atmosphere during calcinations on the structure and properties were investigated by Brunauer-Emmett-Teller(BET) surface area measurements, X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), hydrogen temperature-programmed reduction(H_2-TPR), oxygen storage capacity(OSC), Raman spectroscopy, and X-ray photoelectron spectroscopy(XPS). The results show that the moisture in precursor during calcinations increases the crystal grain size of the cerium zirconium mixed oxides, improving the thermal stability. And the aged surface area of sample after being calcined at1000 ℃ for 4 h reaches 68.8 m~2/g(5.7% increase compared with the common sample). The inert N2 atmosphere endows a great pore-enlarging effect, which leads to high fresh surface area of 148.9 m2/g(13.5% increase compared with the common sample) and big pore volume of 0.5705 mL/g. The redox and oxygen storage capacity are also improved by inert N2 atmosphere with high OSC value of 241.06μmolO_2/g(41.3% increase compared with the common calcination), due to the abundant formation of the crystal defects and oxygen vacancies.     

Hydrogen production from ammonia decomposition over Ni/CeO2 catalyst: Effect of CeO2 morphology

Ammonia(NH₃) decomposition to release CO_x-free hydrogen(H₂) over non-noble catalysts has gained increasing attention.In this study,three nanostructured CeO₂ with different morphologies,viz.rod(R).sphere(Sph),and spindle(Spi),were fabricated and served as supports for Ni/CeO₂ catalyst.The CeO₂supports are different in particle sizes,specific surface area and porosity,resulting in the formation of Ni nanoparticles with distinguished...     

Humidity sensing properties of La~(3+)/Ce~(3+)-doped TiO_2-20 wt.% SnO_2 thin films derived from sol-gel method

The humidity sensing properties of La3+/Ce3+-doped TiO2-20 wt.%SnO2 thin films were studied.Sol-gel method was employed to prepare the films on alumina substrates.By constructing a humidity-impedance measuring system,the sensing behaviors were inspected for the films sintered at different temperatures.Experimental results showed that,0.5 wt.% of La2O3 or Ce2O3 doped films sintered at 500 °C for 2 h had the best humidity sensing properties,the impedance decreasing from 109 ? to below 104 ? in the humidity range of 15-95 RH%.Moreover,Ce3+-doping had better humidity sensing properties than La3+-doping.The doping mechanism was discussed in terms of phase composition,granularity of crystalline and segregation of rare earth ions at grain boundaries.