scholarly journals Photocatalytic Reduction of CO2to Methane on Pt/TiO2Nanosheet Porous Film

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Li Qiu-ye ◽  
Zong Lan-lan ◽  
Li Chen ◽  
Cao Yu-hui ◽  
Wang Xiao-dong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Separation Efficiency ◽  
Pt Nanoparticles ◽  
Porous Film ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Porous Films ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
Average Size

Anatase TiO2nanosheet porous films were prepared by calcination of the orthorhombic titanic acid films at 400°C. They showed an excellent photocatalytic activity for CO2photoreduction to methane, which should be related to their special porous structure and large Brunauer-Emmett-Teller (BET) surface area. In order to further improve the photocatalytic activity, Pt nanoparticles were loaded uniformly with the average size of 3-4 nm on TiO2porous films by the photoreduction method. It was found that the loading of Pt expanded the light absorption ability of the porous film and improved the transformation efficiency of CO2to methane. The conversion yield of CO2to methane on Pt/TiO2film reached 20.51 ppm/h·cm2. The Pt/TiO2nanosheet porous film was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and ultraviolet-visible light diffuse reflectance spectra (UV-vis DRS). Moreover, the transient photocurrent-time curves showed that the Pt/TiO2nanosheet porous film exhibited higher photocurrent, indicating that the higher separation efficiency of the photogenerated charge carriers was achieved.

Photocatalytic Analysis and Characterization of Zn2SnO4 Nanoparticles Synthesized via Hydrothermal Method with Na2CO3 Mineralizer

2010 ◽  
Vol 97-101 ◽  
pp. 19-22 ◽  
Author(s):  
Yu Shiang Wu ◽  
Wen Ku Chang ◽  
Min Jou
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Process ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
Face Centered ◽  
Xrd Patterns

Zinc stannate Zn2SnO4 (ZTO) nanoparticles were synthesized via a hydrothermal process utilizing sodium carbonate (Na2CO3) as a weak basic mineralizer. The samples were hydrothermally treated at 150, 200, and 250oC for 48 h. The X-ray diffraction (XRD) patterns show that the highly-crystalline ZTO nanostructure could be formed in a well-dispersed manner for the 250°C sample at a particle size of less than 50 nm. As determined from transmission electron microscopy (TEM) results, ZTO nanoparticles are face-centered cubic single crystals agglomerated together. The Raman spectra results showed that the ZTO nanocrystals have a spinel structure. Furthermore, photocatalytic activity was tested with methylene blue (MB) by UV irradiation. The ZTO synthesized by the 2 M Na2CO3 mineralizer at 250oC demonstrated excellent photocatalytic activity. The ZTO treated three different ways had three distinct UV-Visible absorption curves, which directly influences their corresponding photocatalytic activity.

Effect of Rb+ -Doping on the Crystallization, Phase Transition and Photocatalytic Activity of Nanosized TiO2 Catalyst

2012 ◽  
Vol 476-478 ◽  
pp. 954-957 ◽  
Author(s):  
Zhao Hui Ni ◽  
Xiao Li Kou ◽  
Xin Yu Ding ◽  
Cun Wang Ge ◽  
Xiao Hui Jing
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Surface Area ◽  
Sol Gel ◽  
Rutile Phase ◽  
Bet Surface Area ◽  
X Rays ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Kinetics Of

In order to study the ion effect on titania phase structure, crystallite size, and photocatalytic activity, Rb+-doped TiO2 nanoparticles were prepared via a modified sol-gel method and characterized by means of X-ray diffraction, Energy Dispersive X-rays spectroscopy and transmission electron microscopy. The photocatalytic activity of the elaborated powders was studied following the degradation of methyl orange. The results indicate that doping Rb+ increases the BET surface area of TiO2 crystals, decreases the crystal size, reduces the diminishing rates of surface area with increasing calcinations temperature, raises the temperature at which anatase changes into rutile phase, and so significantly increases the photocatalytic activity of TiO2. The kinetics of the methyl orange degradation fits Langmuir-Hinshelwood kinetics model well.

Photo-Induced Charge Transfer on Pt/Bi2WO6 Composite Photocatalysts

2020 ◽  
Vol 20 (3) ◽  
pp. 1838-1844 ◽  
Author(s):  
Dong-Qing He ◽  
Hong-Cheng Liu ◽  
Qi Wang ◽  
Qian Yu ◽  
Jin-Ying Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Separation Efficiency ◽  
Pt Nanoparticles ◽  
Transient Photovoltage ◽  
Composite Photocatalysts ◽  
Induced Charge ◽  
Average Size ◽  
Transfer Properties ◽  
Insight Into

Pt/Bi2WO6 composite photocatalysts were prepared by a facile photoreduction method. Pt nanoparticles with an average size of 5–8 nm were successfully deposited on the surface of Bi2WO6 microspheres and the photocatalytic activity of Bi2WO6 was greatly improved by Pt nanoparticles. The photo-induced charge transfer properties of samples were studied by means of surface photovoltage (SPV) and transient photovoltage (TPV) techniques, giving an insight into the intrinsic reasons of the improvement in photocatalytic activity. The SPV and TPV results revealed that the deposited Pt nanoparticles could trap photo-induced electrons and then largely enhance the separation efficiency of photo-induced charge carriers.

Highly Improved Photocatalytic Activity of Magnetically Separable Ferroferric Oxide@Zinc Oxide/Carbon Nitride Nanocomposites and Interface Mechanism

NANO ◽  
2021 ◽  
Author(s):  
D. S. Shi ◽  
B. Hong ◽  
J. N. Mao ◽  
S. Y. Song ◽  
C. X. Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Carbon Nitride ◽  
Separation Efficiency ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photogenerated Electrons ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
High Separation

To develop an efficient and recyclable photocatalyst, ternary magnetic Fe3O4@ZnO/g-C3N4 nanocomposites were synthesized for the photodegradation of methylene blue (MB). The microstructures, magnetic response and photocatalytic activity of the as-prepared nanocomposites were characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), N2 adsorption–desorption isotherms and spectrophotometer. All results indicate that ZnO nanoparticles anchor on the surface of Fe3O4 nanoparticles and Fe3O4@ZnO exists on the surface of g-C3N4 to form Fe3O4@ZnO/g-C3N4 nanocomposites. The photocatalytic activity to MB of Fe3O4@ZnO/g-C3N4 nanocomposites is significantly higher than those of pristine g-C3N4 and Fe3O4@ZnO. Owing to the heterojunctions between the interface of g-C3N4 and ZnO, the high separation efficiency of the photogenerated electrons and holes increases the radicals [Formula: see text]OH and [Formula: see text]O[Formula: see text] to photodegrade MB. Fe3O4@ZnO/g-C3N4 (20%) presents the highest MB removal of 93.74% and could be easily separated from solution with magnetic separation method.

scholarly journals Composite Magnetic Photocatalyst Bi5O7I/MnxZn1−xFe2O4: Hydrothermal-Roasting Preparation and Excellent Photocatalytic Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 118 ◽  
Author(s):  
Hailong Wang ◽  
Longjun Xu ◽  
Chenglun Liu ◽  
Yuan Lu ◽  
Qi Feng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Energy Gap ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Magnetic Photocatalyst ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
Average Recovery Rate

A new composite magnetic photocatalyst, Bi5O7I/MnxZn1−xFe2O4, prepared by a hydrothermal-roasting method was studied. The photocatalytic properties of Bi5O7I/MnxZn1−xFe2O4 were evaluated by degradation of Rhodamine B (RhB) under simulated sunlight irradiation, and the structures and properties were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible light (UV-Vis) diffuse reflectance spectra (DRS), and a vibrating sample magnetometer (VSM). The results indicated that Bi5O7I/MnxZn1−xFe2O4 was an orthorhombic crystal, which was similar to that observed for Bi5O7I. Bi5O7I/MnxZn1−xFe2O4 consisted of irregularly shaped nanosheets that were 40–60 nm thick. The most probable pore size was 24.1 nm and the specific surface area was 7.07 m2/g. Bi5O7I/MnxZn1−xFe2O4 could absorb both ultraviolet and visible light, and the energy gap value was 3.22 eV. The saturation magnetization, coercivity and residual magnetization of Bi5O7I/MnxZn1−xFe2O4 were 3.9 emu/g, 126.6 Oe, and 0.7 emu/g respectively, which could help Bi5O7I/MnxZn1−xFe2O4 be separated and recycled from wastewater under the action of an external magnetic field. The recycling experiments revealed that the average recovery rate of the photocatalyst was 90.1%, and the photocatalytic activity was still more than 81.1% after five cycles.

Synthesis of LaMnO3–Diamond Composites and Their Photocatalytic Activity in the Degradation of Weak Acid Red C-3GN

NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850121 ◽  
Author(s):  
Hao Huang ◽  
Benqian Lu ◽  
Yuanyuan Liu ◽  
Xeuqian Wang ◽  
Jie Hu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Active Sites ◽  
Sol Gel ◽  
Peak Position ◽  
Weak Acid ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
The Fourier Transform

In this study, a series of LaMnO3–diamond composites with varied LaMnO3 mass contents supported on micro-diamond have been synthesized using a sol–gel method. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and the Fourier transform infrared spectra (FTIR). Meanwhile, the photocatalytic performances were also tested by photoluminescence (PL) spectroscopy, ultraviolet–visible diffuse reflection spectra (UV-Vis DRS) and the degradation of weak acid red C-3GN (RC-3GN). Results show that the peak position of LaMnO3 is shifted to low angle after the introduction of diamond, and perovskite particles uniformly distributed on the surface of diamond, forming a network structure, which can increase the active sites and the absorption of dye molecules. When the mass ratio of LaMnO3 and diamond is 1:2 (LMO–Dia-2), the composite shows the most excellent photocatalytic activity. This result offers a sample route to enlarge the range of the application of micro-diamond and provide a new carrier for perovskite photocatalysts.

HYDROTHERMAL SYNTHESIS AND ENHANCED VISIBLE-LIGHT PHOTOCATALYTIC ACTIVITY OF CdS QUANTUM DOTS SENSITIZED CARBON NANOTUBES (CNTs) NANOCOMPOSITE

NANO ◽  
2014 ◽  
Vol 09 (02) ◽  
pp. 1450017 ◽  
Author(s):  
XINLIN LIU ◽  
YANFENG TANG ◽  
CHANGCHANG MA ◽  
YAN YAN ◽  
PENG LV ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
New Type ◽  
Mechanism And Kinetics ◽  
Kinetics Of

A new-type photocatalyst of cadmium sulfide carbon nanotubes ( CdS /CNTs) was prepared by the hydrothermal method. This as-prepared CdS /CNTs composite photocatalyst was proved to exhibit an excellent photocatalytic activity for degradation of tetracycline (TC). Specially, the 95%- CdS –5%-CNTs composite photocatalyst played the best degradation rate (81.2%) in 60 min under the visible light irradiation. Moreover, this 95%- CdS –5%-CNTs composite photocatalyst possessed great stability and could be used at least four cycles with almost no loss of photocatalytic efficiency. Furthermore, the as-synthesized CdS /CNTs composite photocatalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis diffused reflectance spectra (UV-Vis), Raman and thermal gravimetry (TG). In addition, the possible mechanism and kinetics of photodegradation of TC with CdS /CNTs photocatalyst was also discussed.

PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi2Fe4O9 Crystallites

2011 ◽  
Vol 1292 ◽  
Author(s):  
Dengrong Cai ◽  
Jianmin Li ◽  
Shundong Bu ◽  
Shengwen Yu ◽  
Dengren Jin ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectrum ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Peg 400 ◽  
Transmission Electron ◽  
Light Region ◽  
Facile Hydrothermal Route ◽  
Degradation Ratio

ABSTRACTA facile hydrothermal route assisted by polyethylene glycol (PEG) 400 was utilized to synthesize single-phase Bi2Fe4O9 crystallites. X-ray diffraction results showed the products with PEG 400 of 30 g/L exhibited a preferred growth along the (001) plane. Transmission electron microscopy indicated that the morphology of the as-prepared Bi2Fe4O9 crystallites with PEG 400 were plake-like and rod-like. Strong absorption in visible-light region of the products was characterized by UV-vis diffuse reflectance spectrum (UV-DRS). The photocatalytic activity of Bi2Fe4O9 crystallites was evaluated on degradation of methyl orange (MO) under visible light irradiation. For 3 h irradiation, the degradation ratio was increased to 93% with the aid of a small amount of H2O2. The analysis of FT-IR spectra proved that the Bi2Fe4O9 catalysts were remained stable after the photocalytic reactions.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

The effect of silver concentration and calcination temperature on structural and optical properties of ZnO:Ag nanoparticles

2015 ◽  
Vol 29 (01) ◽  
pp. 1450254 ◽  
Author(s):  
M. Shayani Rad ◽  
A. Kompany ◽  
A. Khorsand Zak ◽  
M. E. Abrishami
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Visible Emission ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size

Pure and silver added zinc oxide nanoparticles ( ZnO -NPs and ZnO : Ag -NPs) were synthesized through a modified sol–gel method. The prepared samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. In the XRD patterns, silver diffracted peaks were also observed for the samples synthesized at different calcination temperatures of 500°C, 700°C, 900°C except 1100°C, in addition to ZnO . TEM images indicated that the average size of ZnO : Ag -NPs increases with the amount of Ag concentration. The PL spectra of the samples revealed that the increase of Ag concentration results in the increase of the visible emission intensity, whereas by increasing the calcination temperature the intensity of visible emission of the samples decreases.

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