Photocatalytic Reduction of CO2 over CdxZn1-xS Photocatalysts

2012 ◽  
Vol 610-613 ◽  
pp. 319-322
Author(s):  
Xue Feng Bai ◽  
Xian Da Li
Keyword(s):  
Hexagonal Phase ◽  
Band Gap Energy ◽  
Photocatalytic Reduction ◽  
Surface Photovoltage ◽  
Mercury Lamp ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gap Energy ◽  
Surface Photovoltage Spectroscopy ◽  
Composite Photocatalysts

A series of CdxZn1-xS (x=0.1~0.9) composite photocatalysts were prepared by coprecipitation method. The above-prepared photocatalysts were characterized by X-ray diffraction (XRD), UV-Vis diffusive reflectance spectroscopy (DRS),surface photovoltage spectroscopy (SPS). It was shown from XRD that CdxZn1-xS solid solution semiconductors were of hexagonal phase in agreement with pure CdS. The DRS and SPS results showed that the band gap energy gradually reduced with the increasing of x value in CdxZn1-xS, and when x = 0.7, the Cd0.7Zn0.3S photocatalyst had the strongest surface photovoltage. It was found from photocatalytic reduction of CO2 that the highest HCOOH production rate of 342.64 μmol/(g•h) over Cd0.7Zn0.3S photocatalyst among a series of CdxZn1-xS photocatalysts were obtained under 250 W high pressure mercury lamp.

Study on Band Gap Energy of F Doped TiO2 Nanotubes

2017 ◽  
Vol 889 ◽  
pp. 234-238
Author(s):  
Mohd Hasmizam Razali ◽  
Nur Arifah Ismail ◽  
Mahani Yusoff
Keyword(s):  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Small Diameter ◽  
Ultra Violet ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gap Energy ◽  
Transmission Electron ◽  
Xrd Patterns

Pure and F doped TiO2 nanotubes was synthesized using simple hydrothermal method. The hydrothermal was conducted using teflon-liner autoclave and maintained at 150oC for 24 hours. The characterization of synthesised product was carried out using x-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive of x-ray spectroscopy (EDX) and ultra violet – visible light diffuse reflectance spectroscopy (UV-Vis DRS) for band gap measurements. XRD patterns indicated that anatase TiO2 phase was remained after F doping suggested that fluorine was highly dispersed into TiO2 by substituted with O in the TiO2 lattice to formed TiO2-xFx solid solution. Morphology investigation using TEM found out small diameter of nanotubes structure within 8 – 10 nm of pure and F doped TiO2 nanotubes. The band gap energy (Eg) of both nanotubes samples were almost similar proposing that F doping does not modify the band gap energy.

scholarly journals Optical and Electrical Properties of Nd3+doped Na2O-ZnO-TeO2 Material

2021 ◽  
Vol 12 (6) ◽  
pp. 7927-7941
Keyword(s):  
Optical Band Gap ◽  
Large Range ◽  
Emission Spectra ◽  
Band Gap Energy ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Gap Energy ◽  
Dta And Tg

Neodymium-doped Na2O-ZnO-TeO2 (NZT) glasses were prepared by the conventional melt quenching technique. DTA and TG were used to confirm glass preparation through the glass transition temperature at 447°C for the glass system. The analysis of FTIR spectra and X-ray diffraction described the samples' nature as ionic and amorphous, respectively. The optical band gap energy was estimated using absorption spectra and found to be decreased from 2.63eV to 1.32 eV due to the increase of doping concentration. The intensity of the emission spectra was enhanced for the higher concentration of Nd3+ ions. The dielectric constant of the glass samples was found to be constant for the large range of frequency (3 kHz to 1 MHz). The variation of conductivity with the temperature of the samples had shown the Arrhenius mechanism of conduction.

Effect of bath temperature on the chemical bath deposition of PbSe thin films

1970 ◽  
Vol 6 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Anuar Kassim ◽  
Tan Wee Tee ◽  
Ho Soon Min ◽  
Shanthi Monohorn ◽  
Saravanan Nagalingam
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Chemical Bath Deposition ◽  
Lead Nitrate ◽  
Bath Temperature ◽  
Band Gap Energy ◽  
Sodium Selenate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gap Energy

PbSe thin films are prepared by chemical bath deposition technique over microscope glass substrates from an aqueous acidic bath containing lead nitrate and sodium selenate. The influence of bath temperature on the properties of PbSe film is investigated. The X-ray diffraction analysis showed the deposited films were polycrystalline and having the (111) orientation. The surface morphology study revealed that the grains have cubic shape crystal. The band gap energy was decreased from 2.0 to 1.3 eV as the bath temperature was increased from 40 to 80°C. The films deposited at 80°C showed good crystallinity and uniformly distributed over the surface of substrate with larger grain sizes. Therefore, the optimum bath temperature is 80°C. Keywords: Lead selenide; X-ray diffraction; Band gap energy; Chemical bath deposition; Thin films DOI: 10.3126/kuset.v6i2.4021Kathmandu University Journal of Science, Engineering and Technology Vol.6. No II, November, 2010, pp.126-132

Synthesis and characteristics of ZnS/CdS composite nanocrystals in block copolymer micelle

1999 ◽  
Vol 14 (6) ◽  
pp. 2381-2384 ◽  
Author(s):  
Dayang Wang ◽  
Yaan Cao ◽  
Xintong Zhang ◽  
Xinming Qian ◽  
Xin Ai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Block Copolymer ◽  
Elemental Analysis ◽  
Surface Photovoltage ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Photovoltage Spectroscopy ◽  
Transmission Electron ◽  
Copolymer Micelle

In hydroxylated poly(styrene-b-butadiene-b-styrene) (HO–SBS) micelle, ZnS/CdS composite nanocrystals were prepared by adding Cd2+ ions and Zn2+ ions to the system sequentially. The resulting composites were identified with elemental analysis, transmission electron microscopy, x-ray diffraction, surface photovoltage spectroscopy, and electric field induced surface photovoltage spectroscopy.

Fabrication and Photocatalytic Activity of Ag/Bi2O3

2012 ◽  
Vol 178-181 ◽  
pp. 645-648
Author(s):  
Yan Lu ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Wei Hu
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Methyl Orange Solution ◽  
Reflectance Spectroscopy ◽  
Surface Photovoltage ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Photovoltage Spectroscopy ◽  
Orange Solution

It has been found that the photocatalytic activity of Bi2O3toward the decolorization of Methyl Orange solution can be greatly improved by loading Ag on the surface of Bi2O3using a photodeposition method. The photocatalysts were characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy and surface photovoltage spectroscopy (SPS), respectively. 0.5%Ag/Bi2O3possesses the best photocatalytic activity.

Synthesis and Surface Photoelectric Properties of a Trinuclear Chromium(III) Complex

2013 ◽  
Vol 275-277 ◽  
pp. 2010-2013 ◽  
Author(s):  
Zhong Feng Shi ◽  
Jia Ming Li ◽  
Yan Zhen Yin ◽  
Li Zhang ◽  
Ni Huang ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Surface Photovoltage ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Surface Electron ◽  
Photoelectric Conversion ◽  
Chlorobenzoic Acid ◽  
X Ray ◽  
Surface Photovoltage Spectroscopy ◽  
Photoelectric Properties

A trinuclear Chromium(III) complex [Cr3(μ3-O)(μ2-PCBA)6(CH3OH)3]NO3∙H2O∙CH3OH (HPCBA = 4-Chlorobenzoic acid) has been synthesized and characterized by single-crystal X-ray diffraction, IR spectra, UV-Vis absorption spectra and elemental analysis, which belongs to monoclinic, space group P21/c with a = 12.443 (3), b = 24.543 (5), c =22.094 (7)Å, α = 90°, β =115.76 (2) °, γ =90°, V = 6077 (3)Å3, Z = 4.The surface electron behavior of the chromium complex has been studied emphatically by surface photovoltage spectroscopy (SPS). Structural analyse indicate that the complex is molecular complex. The result of SPS show that there is positive photovoltage response bands within 300–800 nm, which indicate that it possess obvious photoelectric conversion properties. There was a good correlation between the SPS and UV-Vis absorption spectra.

scholarly journals Study of the optical and structural properties of the (ZnO) membrane, which is prepared by the method of thermal steaming by using the closed oven

2019 ◽  
Vol 24 (2) ◽  
pp. 56
Author(s):  
Amna Raad Dahham ◽  
Sabri Jassim Mohammed ◽  
Wlla Mahffod Mohammed
Keyword(s):  
Absorption Coefficient ◽  
Structural Properties ◽  
Band Gap Energy ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transparent Films ◽  
Gap Energy ◽  
Optical Gap Energy ◽  
Permeability Spectrum

This study investigated the optical and structural properties of the (ZnO) membrane, which is prepared by the method of thermal steaming in the vacuum by using the closed oven on glass platforms at room temperature. The crystallization of the membranes prepared by X-ray diffraction pattern was diagnosed. The membranes were found to be polymorphic with hexagonal structure and crystal direction (002), the membranes were annealed for (5,15,25) min at (510°C),the results showed the increased height of peaks with their intensity and decreases in the optical gap energy. The study of optical properties also included the recording of both the absorption spectra and the permeability spectrum of the prepared membranes at the wavelength range (250-1100) nm, Also, the rest of the optical constants were calculated as functions of the photon energy, including (absorption coefficient, extinaction cofficient), Where the value of the absorption coefficient for ZnO thin films varies from (1.4 cm-1 to 2.09cm-1), and the value of  extinaction coefficient  varies from (0.6 to 0.38). Transmission spectra showed highly transparent films with band gap energy varies ranging from 3.47ev to 3.3 eV.    http://dx.doi.org/10.25130/tjps.24.2019.032

scholarly journals PbI2 Single Crystal Growth and Its Optical Property Study

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 589 ◽  
Author(s):  
Lin ◽  
Guo ◽  
Dai ◽  
Lin ◽  
Hsu
Keyword(s):  
Band Gap ◽  
Chemical Vapor ◽  
Band Gap Energy ◽  
Chemical Vapor Transport ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gap Energy ◽  
Photoelectric Properties ◽  
Metal Semiconductor Metal ◽  
Excitonic Transition

In this work, we used the chemical vapor transport (CVT) method to grow PbI2 crystals using iodine as a self-transporting agent. The crystals’ structure, composition, and uniformity were confirmed by X-ray diffraction (XRD) and electron probe microanalysis (EPMA) measurements. We investigated the band gap energy using absorption spectroscopy measurements. Furthermore, we explored the temperature dependence of the band gap energy, which shifts from 2.346 eV at 300 K to 2.487 eV at 20 K, and extracted the temperature coefficients. A prototype photodetector with a lateral metal–semiconductor–metal (MSM) configuration was fabricated to evaluate its photoelectric properties using a photoconductivity spectrum (PC) and persistent photoconductivity (PPC) experiments. The resonance-like PC peak indicates the excitonic transition in absorption. The photoresponse ILight/IDark-1 is up to 200%.

Some electron probe X-ray microanalysis (EPMA)- and (BPES)-related physical investigations on ZnSSe thin-films growth composition-related kinetics

2009 ◽  
Vol 87 (6) ◽  
pp. 653-657 ◽  
Author(s):  
S. Fridjine ◽  
K. Boubaker ◽  
M. Amlouk
Keyword(s):  
Thin Films ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Force Microscopy ◽  
Gap Energy ◽  
Atomic Force ◽  
Composition Changes ◽  
Selenization Process

In this study, ZnSSe epilayers were grown on (111) ZnS sprayed thin films. The spectral analysis was carried out in the region from 400 to 1800 nm. Analyses of the transmittance and (or) reflectance spectra indicate a decrease of the band gap energy value Eg with selenization. As the selenization process changes the structure and property of prepared materials and therefore has a direct effect on their physical properties, one of the concerns of this paper is to investigate the depth-dependent composition changes as guides to monitoring the selenization kinetics. Photothermal, atomic force microscopy (AFM), and X-ray diffraction (XRD) investigations have also been carried out.

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