Optical and structural properties of solid oxide photocatalyst Bi2FeNbO7

2001 ◽  
Vol 16 (1) ◽  
pp. 35-37 ◽  
Author(s):  
Zhigang Zou ◽  
Jinhua Ye ◽  
Hironori Arakawa

Polycrystalline sample of Bi2FeNbO7 was synthesized by the solid-state reaction and characterized by powder x-ray diffraction and Rietveld structure refinement. The optical absorption and structural properties of Bi2FeNbO7 were investigated. It was found that the Bi2FeNbO7 compound has the pyrochlore crystal structure, cubic system with space group Fd3m, and the lattice parameter is a = 10.5233(2) Å. Ultraviolet-visible diffuse reflectance spectroscopy measurement revealed that the band gap of Bi2FeNbO7 is about 2.1(6) eV.

2000 ◽  
Vol 15 (10) ◽  
pp. 2073-2075 ◽  
Author(s):  
Zhigang Zou ◽  
Jinhua Ye ◽  
Hironori Arakawa

A polycrystalline sample of Bi2InNbO7 was synthesized by a solid-state reaction and characterized by powder x-ray diffraction and Rietveld structure refinement. The optical absorption and electrical properties of Bi2InNbO7 were investigated. It was found that the Bi2InNbO7 compound exhibited a direct gap semiconducting behavior. Conductivity measurement showed the compound had an activation energy of 2.62(5) eV. Ultraviolet–visible diffuse reflectance spectroscopy measurement revealed that the band gap of Bi2InNbO7 is about 2.7(4) eV.


2002 ◽  
Vol 17 (6) ◽  
pp. 1446-1454 ◽  
Author(s):  
Zhigang Zou ◽  
Hironori Arakawa ◽  
Jinhua Ye

Substitution effects of Ta5+ by Nb5+ in BiTa1−xNbxO4(0 ≦ x ≧ 1.0) on photocatalytic, photophysical, and structural properties were investigated. The powder x-ray diffraction and Rietveld structural refinement showed that the structure of BiTa1−xNbxO4 at R = Nb/Bi = 0.0 and 0.5 is a triclinic system with space group P1. However, the structure at R = 0.2, 0.8, and 1.0 is an orthorhombic system with space group Pnna. Ultraviolet-visible diffuse reflectance spectroscopy measurement revealed that the band gap of orthorhombic samples is narrower than that of triclinic compounds. The H2 evolution was obtained from an aqueous CH3OH/H2O solution and pure H2O with BiTa1−xNbxO4 under ultraviolet irradiation. The orthorhombic samples exhibit much higher activity than that of triclinic compounds. The orthorhombic compound at R = 0.2 showed the highest activity, which is higher than that of the well-known TiO2 photocatalyst.


2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.


2019 ◽  
Vol 12 (06) ◽  
pp. 1950085 ◽  
Author(s):  
Di Zhao ◽  
Xuezheng An ◽  
Yaxian Sun ◽  
Guihua Li ◽  
Hongyan Liu ◽  
...  

p-n heterojunction Ag2CO3/Ag3PO4/Ni thin films were prepared by electrochemical co-deposition. The surface morphology and structural properties of the thin films were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic (PC) properties of the Ag2CO3/Ag3PO4/Ni composite thin films were investigated by their ability to degrade rhodamine B (RhB) and Congo red (CR) under visible light irradiation. The results showed that the photodegradation efficiency of RhB by an Ag2CO3/Ag3PO4/Ni thin film under visible-light irradiation for 30[Formula: see text]min (98.84%) was 2.64 times higher than that of an Ag3PO4/Ni thin film and 3.44 times higher than of an Ag2CO3/Ni thin film. The presence of a [Formula: see text]-[Formula: see text] heterojunction greatly increased the charge conductivity of the film and its ability to photocatalytically reduce dissolved oxygen, which are the main reasons for the improved PC performance of the Ag2CO3/Ag3PO4/Ni films.


Clay Minerals ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 491-500 ◽  
Author(s):  
L. Fu ◽  
B. M. Weckhuysen ◽  
A. A. Verberckmoes ◽  
R. A. Schoonheydt

AbstractComplexes of Cu(lysine)2+2 and Cu(histidine)2+2 have been intercalated between the layers of saponite clays by a simple cation exchange procedure from aqueous solutions of preformed Cu(amino acid)2-complexes. Successful immobilization was obtained with an amino acid: Cu2+ ratio of 5, and a pH of 10 and 7.3 for lysine and histidine, respectively. The synthesized materials were investigated as powders and as thin films by electron spin resonance (ESR), diffuse reflectance spectroscopy (DRS) and X-ray diffraction (XRD). The light blue clays are characterized by an axially symmetric ESR spectrum with A//= 192 G, g//= 2.23 and g⊥ = 2.07, and a d-d absorption band around 600 nm, due to the intercalated planar Cu2+-complexes. Ammonia interacts reversibly with these intercalated complexes, suggesting the presence of a free coordination site. The novel synthesized materials are active in various oxidation reactions with t-butyl hydroperoxide as oxidant.


2016 ◽  
Vol 35 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Elaheh Esmaeili ◽  
Mohammad Sabet ◽  
Masoud Salavati-Niasari ◽  
Kamal Saberyan

AbstractPbS nanostructures were synthesized successfully via hydrothermal approach with a new precursor. The products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Vis diffuse reflectance spectroscopy (DRS). The effect of different sulfur sources were investigated on product size and morphology.


2014 ◽  
Vol 881-883 ◽  
pp. 1101-1104 ◽  
Author(s):  
Min Jie Zhou ◽  
Peng Cui

In this work, flower-like ZnIn2S4 microspheres were synthesized using a solvothermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic activity of the ZnIn2S4 microspheres was investigated. The ZnIn2S4 microspheres exhibit much higher photocatalytic activity than pure P25 TiO2.


2016 ◽  
Vol 4 (18) ◽  
pp. 6946-6954 ◽  
Author(s):  
E. N. K. Glover ◽  
S. G. Ellington ◽  
G. Sankar ◽  
R. G. Palgrave

The nature and effects of rhodium and antimony doping in TiO2 have been investigated using X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES) and diffuse reflectance spectroscopy.


2014 ◽  
Vol 636 ◽  
pp. 7-10 ◽  
Author(s):  
Pei Song Tang ◽  
Chao Wan Tang ◽  
Jia Ni Ying ◽  
Dong Jing Ni ◽  
Qian Yang ◽  
...  

Using Fe (NO3)3⋅9H2O, Y(NO3)3⋅6H2O and citric acid as the main raw material, the YFeO3 nanoparticles were synthesized by ultrasonic assisted process and calcination. The YFeO3 nanoparticles were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that the perovskite structureYFeO3 (YFeO3-800) can be obtained through the calcination of ultrasonic processed YFeO3 precursors at 800 °C, and the resulting product has a particle size of 70 nm and an optical band gap of 2.0 eV. Consequently, the YFeO3-800 nanoparticles show high photocatalytic activity for decomposition of methyl orange under visible-light irradiation.


2016 ◽  
Vol 1133 ◽  
pp. 664-668
Author(s):  
Hayyiratul Fatimah Mohd Zaid ◽  
Chong Fai Kait ◽  
Mohamed Ibrahim Abdul Mutalib

Titanium dioxide (TiO2) photocatalyts doped with iron metal at different metal loadings were successfully prepared and characterized. The doped photocatalyst were characterized using diffuse reflectance spectroscopy (DR-UV-Vis), X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM).Photooxidative extractive desulfurization of model oil containing dibenzothiophene as the sulfur compound (100ppm) was investigated using the prepared photocatalyst. The photocatalyst with 0.20 wt% Fe metal loading showed the best sulfur removal at 61.13%.


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