scholarly journals Visible Light Assisted Photocatalytic Degradation of Chromium (VI) by Using Nanoporous Fe2O3

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Abhilash Mavinakere Ramesh ◽  
Srikantaswamy Shivanna
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Irradiation Time ◽  
Hollow Structure ◽  
Band Gap Energy ◽  
Nanoporous Structure ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
Chromium Vi ◽  
Set Up

A Fe2O3 nanoporous structure was prepared by using hydrothermal route; its physicochemical properties were effectively characterized using XRF, BET, FT-IR, VSM, SEM and EDX, DLS, XRD, and PL techniques. The surface area of the magnetic nanoporous structure Fe2O3 was higher than the normally synthesized Fe2O3 nanoparticle. The outcome of the photocatalytic removal of the chromium (VI) below the visible light irradiation confirmed that 82.11% of Cr(VI) was degraded by the Fe2O3 nanomaterials at 120 min of irradiation time. The improved photocatalytic activity of the nanoparticle was ascribed to efficient electron-hole separation. Fe2O3 was set up to be a tough and constant photocatalyst throughout recycling experiments. The conceivable mechanism for the electron-hole separation process on the heterojunction was probable. The synthesized samples own low band gap energy and a hollow structure appropriate for the improved photocatalytic activity. The toxicity of the samples was measured by using Mus musculus skin melanoma cells (B16-F10 (ATCC®, CRL-6475TM) which are set up to be safe for human cells; as a result, this systematic approach provides a better alternative upconversion material for integral photoabsorption.

scholarly journals Growth Process and CQDs-modified Bi4Ti3O12 Square Plates with Enhanced Photocatalytic Performance

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 66 ◽  
Author(s):  
Xinxin Zhao ◽  
Hua Yang ◽  
Ziming Cui ◽  
Xiangxian Wang ◽  
Zao Yi
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Growth Process ◽  
Photocatalytic Performance ◽  
Simulated Sunlight ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
X Ray ◽  
Photocurrent Spectroscopy

Bi4Ti3O12 square plates were synthesized via a hydrothermal route, and their growth process was systematically investigated. Carbon quantum dots (CQDs) were prepared using glucose as the carbon source, which were then assembled on the surface of Bi4Ti3O12 square plates via a hydrothermal route with the aim of enhancing the photocatalytic performance. XRD (X-ray powder diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), UV-vis DRS (diffuse reflectance spectroscopy), XPS (X-ray photoelectron spectroscopy), FTIR (Fourier transform infrared spectroscopy), PL (photoluminescence) spectroscopy, EIS (electrochemical impedance spectroscopy) and photocurrent spectroscopy were used to systematically characterize the as-prepared samples. It is demonstrated that the decoration of CQDs on Bi4Ti3O12 plates leads to an increased visible light absorption, slightly increased bandgap, increased photocurrent density, decreased charge-transfer resistance, and decreased PL intensity. Simulated sunlight and visible light were separately used as a light source to evaluate the photocatalytic activity of the samples toward the degradation of RhB in aqueous solution. Under both simulated sunlight and visible light irradiation, CQDs@Bi4Ti3O12 composites with an appropriate amount of CQDs exhibit obviously enhanced photocatalytic performance. However, the decoration of excessive CQDs gives rise to a decrease in the photocatalytic activity. The enhanced photocatalytic activity of CQDs-modified Bi4Ti3O12 can be attributed to the following reasons: (1) The electron transfer between Bi4Ti3O12 and CQDs promotes an efficient separation of photogenerated electron/hole pairs in Bi4Ti3O12; (2) the up-conversion photoluminescence emitted from CQDs could induce the generation of additional electron/hole pairs in Bi4Ti3O12; and (3) the photoexcited electrons in CQDs could participate in the photocatalytic reactions.

scholarly journals Hydrothermal Synthesis and Enhanced Photocatalytic Activity of TiO\(_{2}\)-Fe@CNTs Nanocomposite for Methylene Blue Degradation under Visible Light Irradiation

2015 ◽  
Vol 24 (4) ◽  
pp. 363
Author(s):  
Le Ha Chi ◽  
Pham Duy Long ◽  
Nguyen Van Chuc ◽  
Le Van Hong
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Uv Light ◽  
Band Gap Energy ◽  
Nanocomposite Materials ◽  
Light Irradiation ◽  
Hydrothermal Route ◽  
Methylene Blue Degradation

TiO2 is one of the most attractive metal oxides because of the excellent chemical and photocatalytic properties. However, a problem in the application of TiO2 is the large band gap energy of 3.2 eV, corresponding to its photocatalytic activity under UV-light irradiation of wavelengths <387 nm. In this work, TiO2 nanoparticles doped with iron were grown on the surface of functionalized carbon nanotubes (TiO2-Fe@CNTs) to expand the photoabsorbance of the nanocomposite materials in the visible light region and improve their photocatalytic activity. TiO2-Fe@CNTs nanocomposite materials were synthesized by hydrothermal route in Teflon-sealed autoclave at 180oC for 10h. The FE-SEM and X-Ray diffraction measurements were taken for morphology and structural analysis of TiO2 nanoparticles doped with Fe coating on CNTs. The effects of the iron and CNTs on the enhanced photocatalytic activity for methylene blue degradation under AM 1.5 illumination of 100 mW.cm−2 were investigated.

Synthesis of Cu2(OH)PO4 superstructures with NIR-laser enhanced photocatalytic activity

2020 ◽  
Vol 13 (03) ◽  
pp. 2050015 ◽  
Author(s):  
Lu Cheng ◽  
Nuo Yu ◽  
Yan Zhang ◽  
Zhun Shi ◽  
Haifeng Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Near Infrared ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Photothermal Effect ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
Light Group ◽  
Nir Laser

The development of photocatalysts with wide UV-Vis-near-infrared (NIR) photoabsorption has received tremendous interest for utilizing sunlight efficiently. In this work, Cu2(OH)PO4 superstructures are prepared by a simple hydrothermal route, and they have strong bandgap absorption in UV-Visible region and a distinctive plasmon resonance absorption in NIR region. Under the synergetic illumination of visible light and 980[Formula: see text]nm laser (3.0[Formula: see text]W[Formula: see text]cm[Formula: see text]), Cu2(OH)PO4 superstructures can degrade 89.2% MB with the elevated temperature ([Formula: see text]51∘C) of solution, which is higher than that from visible light group (50.0%), laser group (16.4%), and visible-light/exterior-heating group (62.5%, same temperature at [Formula: see text]51.0∘C). These facts reveal that Cu2(OH)PO4 superstructures exhibit NIR-laser enhanced photocatalytic activity, which not only comes from the photothermal effect-induced temperature elevation, but also mainly results from the increased production of photogenerated electron-hole pairs by NIR-laser. Therefore, Cu2(OH)PO4 superstructures can act as efficient photocatalyst with NIR-laser enhanced photocatalytic activity.

scholarly journals Synergistic Adsorption and Photocatalytic Activity under Visible Irradiation Using Ag-ZnO/GO Nanoparticles Derived at Low Temperature

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Viet Ha Tran Thi ◽  
The Ha Cao ◽  
Tri Nhut Pham ◽  
Tien Thanh Pham ◽  
Manh Cuong Le
Keyword(s):  
Photocatalytic Activity ◽  
Low Temperature ◽  
Visible Light ◽  
Band Gap ◽  
Surface Area ◽  
Irradiation Time ◽  
Removal Rate ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Visible Irradiation

Ag-ZnO/graphene oxide (AG-ZnO/GO) nanocomposite was synthesized via facile aqueous solution reactions at low temperature in order to improve the photocatalytic activity for cationic dye removal under visible light irradiation. Analytical techniques were carried out in order to determine the abilities including structure, state of elements, morphology, and surface area of synthesized materials. Ag-ZnO/GO nanocomposite presented an extremely high removal rate of methylene blue (MB) not only under UV light (over 99% removal) but also under visible light (85% removal) during the same irradiation time. In this study, initial process parameters of catalyst dosage, MB concentration, and pH of the solution were also examined for MB removal efficiency effects. The proposed mechanisms for the increased removal of MB by Ag-ZnO/GO nanocomposite under visible irradiation include increased photocatalytic degradation, mainly due to increased charge transfer capacity by lowering band gap energy; minimized recombination of the excited electron-hole pairs of ZnO with the addition of Ag into the ZnO crystal lattice; and an increased adsorption capacity with the addition of GO with high surface area and semiconductor function with zero band gap energy.

scholarly journals Enhanced Visible-Light Photocatalytic Performance of SAPO-5-Based g-C3N4 Composite for Rhodamine B (RhB) Degradation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Redox Reactions ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Thermal Polymerization ◽  
Light Illumination ◽  
Electron Hole ◽  
Visible Light Illumination ◽  
Visible Light Photocatalytic

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.

scholarly journals Visible Light Catalytic Degradation of Aniline Wastewater over Multishaped BiOBr Microcrystals

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Jun Zhang ◽  
Huabo Li ◽  
Hairui Yao ◽  
Hao Zhang
Keyword(s):  
Ionic Liquid ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrothermal Route ◽  
Degradation Ratio ◽  
Soft Templating ◽  
Different Shapes ◽  
Simulated Wastewater ◽  
Surface Microstructures ◽  
Templating Effect

The photooxidation process of aniline-containing simulated wastewater under visible light irradiation over BiOBr microcrystal grains with different shapes was studied. The distinctive surface microstructures of the BiOBr microcrystals, like clustered flower petals and quadrate lamellas, were produced by using imidazole ionic liquid and inorganic bromide as Br sources and by solvothermal and hydrothermal route, respectively. The ionic liquid not only can impact the products’ morphology, but also can largely improve the photocatalytic activity of the BiOBr microcrystals due to the soft templating effect. The top degradation ratio of the aniline wastewater photocatalyzed by lamellar BiOBr crystals is 23.71%, but the equivalent value photocatalyzed by flower petal-like BiOBr crystals is almost twice as much; that is, it reaches 46.51%. The photodegradation effect and mechanism over differently shaped BiOBr microcrystals have been compared.

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.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

ChemInform Abstract: Synthesis of Bi3NbO7 Nanoparticles with a Hollow Structure and Their Photocatalytic Activity under Visible Light.

ChemInform ◽  
2011 ◽  
Vol 42 (43) ◽  
pp. no-no
Author(s):  
Jingrui Fang ◽  
Junfeng Ma ◽  
Yong Sun ◽  
Zhensen Liu ◽  
Chang Gao
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Hollow Structure
Sign in / Sign up

Export Citation Format

Share Document