Hydrothermal synthesis of BiVO4/Bi2MoO6 composites with enhanced photocatalytic activity

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744059 ◽  
Author(s):  
Chaoqi Xu ◽  
Hongzhi Qian ◽  
Haibo Yong ◽  
Xiaogu Huang ◽  
Wei Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Molar Ratio ◽  
Moderate Amount ◽  
Molar Ratios ◽  
Photocatalytic Activities ◽  
Efficient Charge ◽  
One Step ◽  
Carrier Separation ◽  
The One ◽  
Positive Effect

BiVO4/Bi2MoO6 composites have been fabricated via the one-step hydrothermal method. The properties of composites were tailored by altering the V/Mo molar ratios. Photocatalytic activities were evaluated by measuring degradation of RhB under visible-light irradiation. BiVO4/Bi2MoO6 composites with V/Mo molar ratio of 8:1 possessing the optimal photocatalytic performance. The enhanced photocatalytic activity was attributed to the efficient charge carrier separation of composite heterostructures. In addition, the study of adsorption and photocatalytic activity suggested that a moderate amount of adsorption has a positive effect on photocatalytic reaction.

scholarly journals Photocatalytic Improvement under Visible Light inTiO2Nanoparticles by Carbon Nanotube Incorporation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mathana Wongaree ◽  
Siriluk Chiarakorn ◽  
Surawut Chuangchote
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Sol Gel ◽  
Multiwall Carbon Nanotubes ◽  
High Specific Surface Area ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Calcination Temperatures ◽  
Photocatalytic Activities ◽  
Multiwall Carbon

Photocatalytic activity ofTiO2nanoparticles was successfully enhanced by addition of multiwall carbon nanotubes (MWCNT) to make CNT/TiO2nanocomposites by sol-gel method at ambient temperature. CNT treated by HNO3 : H2SO4treatment (1 : 3 v/v) was mixed withTiO2nanoparticles at various molar ratios and calcination temperatures. The optimal molar ratio of CNT : TiO2was found at 0.05 : 1 by weight. The optimal calcination condition was 400°C for 3 h. From the results, the photocatalytic activities of CNT/TiO2nanocomposites were determined by the decolorization of 1 × 10−5 M methylene blue (MB) under visible light. CNT/TiO2nanocomposites could enhance the photocatalytic activity and showed faster for the degradation of MB with only 90 min. The degradation efficiency of the MB solution with CNT/TiO2nanocomposite achieved 70% which was higher than that with pristineTiO2(22%). This could be explained that CNT preventsTiO2from its agglomeration which could further enhance electron transfer in the composites. In addition, CNT/TiO2nanocomposites had high specific surface area (202 m2/g) which is very promising for utilization as a photocatalyst for environmental applications.

scholarly journals Geopolymer-TiO2 Nanocomposites for Photocsatalysis: Synthesis by One-Step Adding Treatment Versus Two-Step Acidification Calcination

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 658 ◽  
Author(s):  
Xiaohui Yang ◽  
Yi Liu ◽  
Chunjie Yan ◽  
Ronghua Peng ◽  
Hongquan Wang
Keyword(s):  
Photocatalytic Activity ◽  
Treatment Process ◽  
Photocatalytic Efficiency ◽  
Step Method ◽  
Calcination Process ◽  
Tio2 Particles ◽  
Study Results ◽  
Photocatalytic Activities ◽  
One Step ◽  
The One

Geopolymer-TiO2 nanocomposites were prepared by two different techniques, namely the two-step acidification calcination treatment and one-step adding method. The potential photocatalytic activities of geopolymer-TiO2 nanocomposites prepared by the two different methods were tested and compared. Nanocomposites prepared via the one-step process showed better photocatalytic activity. The amount of TiO2 particles loaded on the surface of the foaming materials was investigated by XRD and SEM-Mapping. By comparing with the sample obtained from two-step treatment, the TiO2 particles were distributed uniformly on the surface of the foaming materials for the sample obtained from the one-step method in this study. Results showed that the specific surface area of the geopolymer-TiO2 prepared by the one-step treatment process (28.67 m2/g) was significantly lower than the two-step acidification calcination process (215.04 m2/g), while the photocatalytic efficiency with methylene blue trihydrate (MB) was better. This is due to the more stable structure of geopolymer-TiO2 nanocomposites, the better dispersion and more loading of TiO2 particles on the foaming materials surfaces, leading to the enhanced photocatalytic activity.

Synthesis and Photocatalytic Activity of Ag-Doped BiVO4

2013 ◽  
Vol 734-737 ◽  
pp. 2204-2209 ◽  
Author(s):  
Wen Zhao ◽  
Chao Hao Hu ◽  
Ran Chen ◽  
Feng Zheng Lv ◽  
Yan Zhong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Degradation Rate ◽  
Dopant Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Activities ◽  
One Step ◽  
The One ◽  
Scanning Electron

Ag-doped BiVO4 semiconductor photocatalysts were synthesized via the one-step hydrothermal method. The microstructure and morphology of catalysts were characterized by using X-ray diffraction, Scanning electron microscopy, and Energy dispersive X-ray detector (EDS) and photocatalytic activities of BiVO4 catalysts with and without Ag doping were evaluated by degrading methylene blue (MB) under visible-light irradiation. UV-Vis absorption spectra were measured to evaulate the photocatalytic activity of the as-synthesized catalysts. The results suggested that Ag-doped BiVO4 with larger rod-like particle size but better crystallnity has the stronger UV absorption. In comparison with pure BiVO4, degradation rate of MB was increased about 18% in Ag-doped BiVO4 with the Ag+ dopant concentration of 15 mol%.

Few-Layered MoS2 Nanoparticles Loaded TiO2 Nanosheets with Exposed {001} Facets for Enhanced Photocatalytic Activity

NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850129 ◽  
Author(s):  
Chujun Chen ◽  
Xia Xin ◽  
Jinniu Zhang ◽  
Gang Li ◽  
Yafeng Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Charge Carrier ◽  
Visible Light ◽  
Recombination Rate ◽  
Active Species ◽  
Molar Ratio ◽  
Carrier Recombination ◽  
Tio2 Nanosheets ◽  
Photocatalytic Activities ◽  
Charge Carrier Recombination

To improve the high charge carrier recombination rate and low visible light absorption of {001} facets exposed TiO2 [TiO2(001)] nanosheets, few-layered MoS2 nanoparticles were loaded on the surfaces of TiO2(001) nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the MoS2–TiO2(001) nanocomposites exhibited much enhanced photocatalytic activities compared with the pure TiO2(001) nanosheets. At an optimal Mo/Ti molar ratio of 25%, the MoS2–TiO2(001) nanocomposites displayed the highest photocatalytic activity, which took only 30[Formula: see text]min to degrade 50[Formula: see text]mL of RhB (50[Formula: see text]mg/L). The active species in the degradation reaction were determined to be h[Formula: see text] and [Formula: see text]OH according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% MoS2–TiO2(001) nanocomposites.

Effect of KCl Addition upon the Photocatalytic Activity of Zinc Sulphide

2011 ◽  
Vol 318 ◽  
pp. 1-10
Author(s):  
Dipti Vaya ◽  
Abhilasha Jain ◽  
Savitri Lodha ◽  
V. K. Sharma ◽  
Suresh C. Ameta
Keyword(s):  
Photocatalytic Activity ◽  
Light Intensity ◽  
Zinc Sulphide ◽  
Molar Ratio ◽  
Eosin Y ◽  
Molar Ratios ◽  
Ph Concentration

In the present investigation the photocatalytic activity of zinc sulphide has been enhanced using KCl in different molar ratios. The progress of the reaction was monitored spectrophotometrically. The effect of various parameters like pH, concentration of dye, amount of semiconductor, light intensity etc. upon the rate of photocatalytic bleaching of eosin Y has been observed. The molar ratio of KCl: ZnS = 0.25 was found to be a most efficient mixture for bleaching of eosin Y. A tentative mechanism for the photocatalytic bleaching of the dye has also been proposed.

Synthesis of Nanoporous Materials Al-MCM-41 from Natural Halloysite

NANO ◽  
2015 ◽  
Vol 10 (01) ◽  
pp. 1550005 ◽  
Author(s):  
Yaling Xie ◽  
Aidong Tang ◽  
Huaming Yang
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Halloysite Nanotubes ◽  
Nanoporous Materials ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Naoh Solution ◽  
The One ◽  
Mcm 41

Nanoporous materials Al -MCM-41 with varying Si / Al molar ratios have been successfully synthesized from natural clay mineral halloysite nanotubes (HNTs). Hydrothermal treatment of acid-pretreated HNTs and NaOH solution resulted in the one-step synthesis of final nanoporous products by using surfactant. The effects of Si / Al molar ratios (7.7, 61.0 and 176.5) on the surface area, porosity and degree of structural order of Al -MCM-41 materials have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption–desorption measurements and Fourier transform infrared (FTIR) spectra techniques. The results indicated that Si / Al molar ratio had important effect on the characteristics of nanoporous materials, and Al -MCM-41 with an intermediate Si / Al molar ratio of 61.0 exhibited excellent characteristics with high degree of order, high surface area (S BET ) of 1033 m2/g and pore volume of 0.92 mL/g.

LC Polyimides 29. Non-Crystalline Cholesteric Copoly(Ester-Imide)s Derived from Adipic Acid and Isosorbide

1997 ◽  
Vol 9 (2) ◽  
pp. 91-104 ◽  
Author(s):  
Hans R Kricheldorf ◽  
Thorsten Krawinkel
Keyword(s):  
Glass Transition ◽  
Adipic Acid ◽  
The Other ◽  
Molar Ratio ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Molar Ratios ◽  
Melting Temperatures ◽  
Low Concentrations ◽  
The One

Numerous cholesteric copoly(ester-imide)s were prepared from mixtures of isosorbide and tert.-buthylhydroquinone (or other diphenols), on the one hand, and mixtures of adipoylchloride and N-(4-chlorocarbonylphenyl) trimellitimide chloride on the other. When the molar ratio of isosorbide/diphenol was varied, Grandjean textures were only observed for low concentrations of isosorbide (5/95 or 10/90). In the case of adipoylchloride/imide dichloride molar ratios of 30/70–50/50 favoured the formation of Grandjean textures. Most copoly(esterimide)s were non-crystalline with glass transition temperatures ( Tgs) between 90 and 190 °C. In several cases the Grandjean textures were frozen in by cooling below Tg. Such copoly(esterimide)s may be useful as pigments. All copoly(ester-imide)s containing methylhydroquinone were semicrystalline with melting temperatures in the range of 240–270 °C.

Efficient Sunlight Active Nanocomposite Photocatalyst for Degradation of Pollutant Organic Dyes

2013 ◽  
Vol 726-731 ◽  
pp. 650-653
Author(s):  
Li Mei Duan ◽  
Jing Hai Liu ◽  
Qing Yu Pang ◽  
Ling Xu ◽  
Zong Rui Liu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Treatment Process ◽  
Organic Dyes ◽  
Environmental Pollutants ◽  
Organic Dye ◽  
Water Treatment Process ◽  
One Step ◽  
Pollutants Removal ◽  
The One

The sunlight activated photocatalysts are urgently needed for the applications of photocatalytic techniques to environmental pollutants removal. Herein, we report the one-step hydrothermally prepared CdS/TiO2 nanocomposite photocatalyst that is active in the degradation of pollutant organic dyes under solar light. The morphology and components are confirmed by TEM, SEM and XRD. With methylene blue (MB) as the model pollutant organic dye, the photocatalytic activity of CdS/TiO2 nanocomposite photocatalyst under sunlight is demonstrated, and 80% MB is removed after 120 minutes sunlight illumination. Besides, the influences of pH, the amount of photocatalyst and the addition of H2O2 on photocatalytic activity for the degradation of MB are also investigated to mimic water treatment process.

scholarly journals Hydrogen and Oxygen Evolution in a Membrane Photoreactor Using Suspended Nanosized Au/TiO2 and Au/CeO2

2019 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
Tiziana Marino ◽  
Alberto Figoli ◽  
Antonio Molino ◽  
Pietro Argurio ◽  
Raffaele Molinari
Keyword(s):  
Oxygen Evolution ◽  
Membrane Reactor ◽  
Experimental Tests ◽  
Ion Concentration ◽  
Oxygen Generation ◽  
Photocatalytic System ◽  
One Step ◽  
The One ◽  
Positive Effect

Photocatalysis combined with membrane technology could offer an enormous potential for power generation in a renewable and sustainable way. Herein, we describe the one-step hydrogen and oxygen evolution through a photocatalytic membrane reactor. Experimental tests were carried out by means of a two-compartment cell in which a modified Nafion membrane separated the oxygen and hydrogen evolution semi-cells, while iron ions permeating through the membrane acted as a redox mediator. Nanosized Au/TiO2 and Au/CeO2 were employed as suspended photocatalysts for hydrogen and oxygen generation, respectively. The influence of initial Fe3+ ion concentration, ranging from 5 to 20 mM, was investigated, and the best results in terms of hydrogen and oxygen evolution were registered by working with 5 mM Fe3+. The positive effect of gold on the overall water splitting was confirmed by comparing the photocatalytic results obtained with the modified/unmodified titania and ceria. Au-loading played a key role for controlling the photocatalytic activity, and the optimal percentage for hydrogen and oxygen generation was 0.25 wt%. Under irradiation with visible light, hydrogen and oxygen were produced in stoichiometric amounts. The crucial role of the couple Fe3+/Fe2+ and of the membrane on the performance of the overall photocatalytic system was found.

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