scholarly journals Mixed valence Sn doped (CH3NH3)3Bi2Br9 produced by mechanochemical synthesis

2021 ◽  
Author(s):  
Xiaohan Jia ◽  
Yuhan Liu ◽  
Robin Perry ◽  
Ivan Parkin ◽  
Robert Palgrave
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Near Infrared ◽  
Mixed Valence ◽  
Mechanochemical Reaction ◽  
Luminescent Materials ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solar Absorbers

Bismuth halides with formula A3Bi2X9, where A is an inorganic or organic cation, show desirable properties as solar absorbers and luminescent materials. Control of structural and electronic dimensionality of these compounds is important to yield materials with good light absorption and charge transport. Here we report mechanochemical reaction of (CH3NH3)3Bi2Br9 with SnBr2 at room temperature in air, yielding a material with strong absorption across the visible and near-infrared (NIR) region. We attribute this to mixed valence doping of Sn(II) and Sn(IV) on the Bi site. X-ray diffraction shows no secondary phases, even after heating at 200oC to improve crystallinity. X-ray photoelectron spectroscopy suggests the presence of Sn(II) and Sn(IV) states. A similar approach to dope Sn into the iodide analogue (CH3NH3)3Bi2I9 was unsuccessful.

scholarly journals Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng
Keyword(s):  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Degradation Rate ◽  
Model Compound ◽  
Vibrating Sample Magnetometer ◽  
Simulated Sunlight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

scholarly journals A novel and potentially scalable CVD-based route towards SnO2:Mo thin films as transparent conducting oxides

2021 ◽  
Author(s):  
Tianlei Ma ◽  
Marek Nikiel ◽  
Andrew G. Thomas ◽  
Mohamed Missous ◽  
David J. Lewis
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Mixed Valence ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conducting Oxides ◽  
Valence States ◽  
3 Omega ◽  
First Time

AbstractIn this report, we prepared transparent and conducting undoped and molybdenum-doped tin oxide (Mo–SnO2) thin films by aerosol-assisted chemical vapour deposition (AACVD). The relationship between the precursor concentration in the feed and in the resulting films was studied by energy-dispersive X-ray spectroscopy, suggesting that the efficiency of doping is quantitative and that this method could potentially impart exquisite control over dopant levels. All SnO2 films were in tetragonal structure as confirmed by powder X-ray diffraction measurements. X-ray photoelectron spectroscopy characterisation indicated for the first time that Mo ions were in mixed valence states of Mo(VI) and Mo(V) on the surface. Incorporation of Mo6+ resulted in the lowest resistivity of $$7.3 \times 10^{{ - 3}} \Omega \,{\text{cm}}$$ 7.3 × 10 - 3 Ω cm , compared to pure SnO2 films with resistivities of $$4.3\left( 0 \right) \times 10^{{ - 2}} \Omega \,{\text{cm}}$$ 4.3 0 × 10 - 2 Ω cm . Meanwhile, a high transmittance of 83% in the visible light range was also acquired. This work presents a comprehensive investigation into impact of Mo doping on SnO2 films synthesised by AACVD for the first time and establishes the potential for scalable deposition of SnO2:Mo thin films in TCO manufacturing. Graphical abstract

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

Mechanochemical reactions in the system FeTiO3–Si

1998 ◽  
Vol 13 (12) ◽  
pp. 3499-3503
Author(s):  
Ying Chen ◽  
J. S. Williams
Keyword(s):  
Room Temperature ◽  
Reaction Rate ◽  
Thermal Analyses ◽  
Mechanochemical Reaction ◽  
X Ray Diffraction ◽  
Reaction Stage ◽  
X Ray ◽  
Powder Composition ◽  
Si Content ◽  
Mechanochemical Reactions

Mechanochemical reactions in the system FeTiO3 –Si have been investigated as functions of the powder composition and milling conditions, using x-ray diffraction and thermal analyses. Reduction reactions of FeTiO3 by Si were observed during room-temperature milling with the formation of α–Fe, amorphous SiOx, nanocrystalline TiO2, or intermetallic compounds, depending on the Si content. The mechanochemical reaction process consists of a mechanical activation stage and a reaction stage. Higher milling intensity leads to a shorter activation step and a higher reaction rate.

Hydrothermal Synthesis and Room Temperature Ferromagnetism of Ni-Doped Rod-Like ZnO Particles

2014 ◽  
Vol 934 ◽  
pp. 71-74
Author(s):  
Lian Mao Hang ◽  
Zhao Ji Zhang ◽  
Zhi Yong Zhang
Keyword(s):  
Quantum Interference ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Hexagonal Wurtzite Structure ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Particles

Ni-doped rod-like ZnO particles with doping concentration of 1 at.% were synthesized at 200°C by hydrothermal method and characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and superconducting quantum interference device (SQUID). The results show that the as-synthesized samples are pure hexagonal wurtzite structure without metallic Ni or other secondary phases and display rod-like shape with smooth surface. The magnetization measurements reveal that the Ni-doped rod-like ZnO particles show ferromagnetic behavior at room temperature. The saturation magnetization and coercive field are 0.0046 emu/g and 15 Oe, respectively.

Growth and Magneto-Optical Properties of CaTbAlO4 Crystal

2011 ◽  
Vol 306-307 ◽  
pp. 1722-1727 ◽  
Author(s):  
Man Mei ◽  
Li Li Cao ◽  
Yan He ◽  
Ru Ru Zhang ◽  
Fei Yun Guo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Single Crystal ◽  
Room Temperature ◽  
Near Infrared ◽  
Visible Region ◽  
Czochralski Method ◽  
Optical Devices ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectral

The calcium terbium aluminate (CaTbAlO4) single crystal was grown by Czochralski method successfully for the first time.The structure of the crystal was determined by X-ray diffraction analysis.The transmission spectrum of the crystal was measured at room temperature at the wavelength of 400-1500nm.The specific Faraday rotation of the single crystal was surveyed at room temperature at the wavelength 532nm, 633nm, and 1064nm respectively.The Verdet constants of the CaTbAlO4 crystal are calculated and the results show that the Verdet constants of CaTbAlO4 are around 110% higher than that of TGG in the visible and near-infrared spectral region.Therefore,crystal CaTbAlO4 can be promising material for the fabrication of magneto-optical devices in the visible region.

XRD and XPS studies of room temperature spontaneous interfacial reaction of CeO2 thin films on Si and Si3N4 substrates

RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 62935-62939 ◽  
Author(s):  
Parthasarathi Bera ◽  
Chinnasamy Anandan
Keyword(s):  
Thin Films ◽  
Interfacial Reaction ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Interfacial Reactions ◽  
X Ray Diffraction ◽  
X Ray

X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) investigations of interfacial reactions between Ce and Si have been carried out on as-deposited and 15 month aged CeO2/Si and CeO2/Si3N4 thin films.

scholarly journals Room-Temperature Formation of Hard BCx Films by Low Power Magnetron Sputtering

2021 ◽  
Vol 11 (21) ◽  
pp. 9896
Author(s):  
Veronica Sulyaeva ◽  
Maxim Khomyakov ◽  
Marina Kosinova
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Film Properties ◽  
X Ray ◽  
Sputtering Power ◽  
Chemical States ◽  
Rf Signal ◽  
Dual Target

Boron carbide is one of the most important non-metallic materials. Amorphous BCx films were synthesized at room temperature by single- and dual-target magnetron sputtering processes. A B4C target and C target were operated using an RF signal and a DC signal, respectively. The effect of using single- and dual-target deposition and process parameters on the chemical bonding and composition of the films as well as their functional properties were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray energy dispersive analysis, X-ray diffraction, ellipsometry, and spectrophotometry. It was found that the film properties depend on the sputtering power and the used targets. EDX data show that the composition of the samples varied from B2C to practically BC2 in the case of using an additional C target. According to the XPS data, it corresponds to the different chemical states of the boron atom. A nanoindentation study showed that the film with a composition close to B2C deposited with the highest B4C target power reached a hardness of 25 GPa and Young’s modulus of 230 GPa. The optical properties of the films also depend on the composition, so the band gap (Eg) of the BCx film varied in the range of 2.1–2.8 eV, while the Eg of the carbon-rich films decreased to 1.1 eV.

scholarly journals A Simple and Facile Solvothermal Synthesis of Hierarchical PbS Microstars with Multidendritic Arms and Their Optical Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yong-Fang Li ◽  
Ming Zhang ◽  
Qi-Jing Yang ◽  
Feng-Xian Zhang ◽  
Mei-Qi Zheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Solar Absorbers ◽  
Transmission Electron ◽  
Ir Photodetectors ◽  
Ft Ir

A simple and facile approach was developed in the solvothermal synthesis of hierarchical PbS microstars with multidendritic arms, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and photoluminescence (PL) spectroscopy. The morphologies of PbS products were strongly determined by the reaction time and temperature, the ratios of the precursors, and the mixed solvent with various components, and thereby their possible formation mechanism was discussed in some detail. The as-prepared PbS crystals displayed a sharp and strong photoluminescent peak at 437 nm at room temperature. It has potential and practical applications in photoluminescence, photovoltaics, IR photodetectors, electroluminescence, and solar absorbers.

scholarly journals Synthesis of Metal Nanoparticles by Microorganisms

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 589 ◽  
Author(s):  
Yugo Kato ◽  
Michio Suzuki
Keyword(s):  
Metal Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Energy Efficient ◽  
Room Temperature ◽  
Molecular Mechanisms ◽  
Green Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Toxicity ◽  
Temperature And Pressure

Metal nanoparticles (NPs), with sizes ranging from 1–100 nm, are of great scientific interest because their functions and features differ greatly from those of bulk metal. Chemical or physical methods are used to synthesize commercial quantities of NPs, and green, energy-efficient approaches generating byproducts of low toxicity are desirable to minimize the environmental impact of the industrial methods. Some microorganisms synthesize metal NPs for detoxification and metabolic reasons at room temperature and pressure in aqueous solution. Metal NPs have been prepared via green methods by incubating microorganisms or cell-free extracts of microorganisms with dissolved metal ions for hours or days. Metal NPs are analyzed using various techniques, such as ultraviolet-visible spectroscopy, electron microscopy, X-ray diffraction, electron diffraction, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Numerous publications have focused on microorganisms that synthesize various metal NPs. For example, Ag, Au, CdS, CdSe, Cu, CuO, Gd2O3, Fe3O4, PbS, Pd, Sb2O3, TiO2, and ZrO2 NPs have been reported. Herein, we review the synthesis of metal NPs by microorganisms. Although the molecular mechanisms of their synthesis have been investigated to some extent, experimental evidence for the mechanisms is limited. Understanding the mechanisms is crucial for industrial-scale development of microorganism-synthesized metal NPs.

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