Immobilization of BiOBr/BiOI Hierarchical Microspheres on Fly Ash Cenospheres as Visible Light Photocatalysts

2016 ◽  
Vol 69 (1) ◽  
pp. 119 ◽  
Author(s):  
Li Lin ◽  
Ya Wang ◽  
Manhong Huang ◽  
Donghui Chen
Keyword(s):  
Photocatalytic Activity ◽  
Fly Ash ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Three Dimensional ◽  
One Pot ◽  
Transmission Electron ◽  
Hierarchical Microspheres ◽  
2D Nanosheets ◽  
Fly Ash Cenospheres

Three-dimensional (3D) BiOBr/BiOI hierarchical microspheres were successfully fabricated on the surface of fly ash cenospheres (FACs) via a facile one-pot solvothermal method for the first time. The as-prepared samples were characterized by XRD, SEM, energy-dispersive X-ray spectroscopy, UV–visible diffuse reflectance spectroscopy, and high-resolution transmission electron microscopy. The results indicated that the loaded hierarchical microspheres exhibited a uniform distribution, and some aggregation was observed. These well-dispersed hierarchical microspheres were composed of 2D nanosheets, which possess heterojunction structures. Based on the photodegradation tests examining the removal of rhodamine B from water under visible light irradiation (λ > 420 nm), the photocatalytic activity of BiOB/BiOI/FACs was superior to that of BiOBr/FACs and BiOI/FACs. A proposed mechanism for the enhanced photocatalytic activity displayed by BiOB/BiOI/FACs is discussed.

scholarly journals Photocatalytic Activity of Monosized AuZnO Composite Nanoparticles

2018 ◽  
Vol 9 (1) ◽  
pp. 111 ◽  
Author(s):  
Chenguang Ma ◽  
Xianhong Wang ◽  
Shixia Zhan ◽  
Xuemei Li ◽  
Xiao Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Ethylene Glycol ◽  
Visible Light ◽  
Composite Nanoparticles ◽  
Narrow Particle Size Distribution ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Suitable Amount ◽  
Copolymer Poly

Photocatalytic activity of monosized AuZnO composite nanoparticles with different compositions were synthesized by the one-pot polyol procedure, using the triblock copolymer poly(ethylene glycol)-block-poly(propylene glycol)-blockpoly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The structure and morphology of the composite nanoparticles were analyzed by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), selected area electron diffraction (SAED), a transmission electron microscope (TEM) and high resolution transmission electron microscopy (HRTEM). The characterization showed that the AuZnO composite nanoparticles were spherical, with narrow particle size distribution and high crystallinity. The Fourier transform infrared spectroscopy (FTIR) study confirms the PEO-PPO-PEO molecules on the surface of the composite nanoparticles. The investigations by ultraviolet-visible light absorbance spectrometer (UV-Vis) and photoluminescence spectrophotometer (PL) demonstrate well the dispersibility and excellent optical performance of the AuZnO composite nanoparticles. Photocatalytic activity and reusability of the AuZnO nanoparticles in UV and visible light regions was evaluated by the photocatalytic degradation of Rhodamine B (RhB). The experimental results show that the AuZnO composite nanoparticles with a suitable amount of Au loading have stability and improved photocatalytic activity. AuZnO composite nanoparticles are effective and stable for the degradation of organic pollutants in aqueous solution.

scholarly journals Synthesis of TiO2/Pd and TiO2/PdO Hollow Spheres and Their Visible Light Photocatalytic Activity

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jing Yan ◽  
Xiaojuan Li ◽  
Bo Jin ◽  
Min Zeng ◽  
Rufang Peng
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Diffuse Reflectance Spectroscopy ◽  
Hollow Spheres ◽  
Active Species ◽  
Degradation Efficiency ◽  
Diffraction Field ◽  
Transmission Electron

A series of TiO2, TiO2/Pd, and TiO2/PdO hollow sphere photocatalysts was successfully prepared via a combination of hydrothermal, sol-immobilization, and calcination methods. The structure and optical properties of the as-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Telleranalysis, Barrett-Joyner-Halenda measurement, and UV-Vis diffuse reflectance spectroscopy. The photocatalysis efficiencies of all samples were evaluated through the photocatalytic degradation of rhodamine B under visible light irradiation. Results indicated that TiO2/PdO demonstrated a higher photocatalytic activity (the photocatalytic degradation efficiency could reach up to 100% within 40 min) than the other samples and could maintain a stable photocatalytic degradation efficiency for at least four cycles. Finally, after using different scavengers, superoxide and hydroxyl radicals were identified as the primary active species for the effectiveness of the TiO2/PdO photocatalyst.

scholarly journals Preparation and Characterization of(I2)nSensitized NanoporousTiO2with Enhanced Photocatalytic Activity under Visible-Light Irradiation

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Juzheng Zhang ◽  
Xin Liu ◽  
Shanmin Gao ◽  
Quanwen Liu ◽  
Baibiao Huang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Chemical Properties ◽  
Reaction Model ◽  
Raw Material ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Adsorption Desorption

A yellow/brown powder of(I2)nsensitized nanoporous TiO2was obtained via an hydrolysis with TiCl4and iodine hydrosol as raw material. I2nanoparticles in the hydrosol were used as seeds to initiate the nucleation of a precursory TiO2shell. The hybridized jumbles were further calcinated at different temperatures. The structure, crystallinity, morphology, and other physical-chemical properties of the samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2adsorption-desorption isotherms measurements, and UV-vis diffuse reflectance spectroscopy (DRS). The formation mechanism of these(I2)nsensitized nanoporous TiO2is discussed. Methylene blue solutions were used as model wastewater to evaluate the visible light photocatalytic activity of the samples. The results indicate that iodine can exist even in high-temperature calcination for iodine being encapsulated in the nanocavities inside TiO2. The degradation of methylene blue (MB) accorded with the first-order reaction model.

scholarly journals Improved Visible Light Photocatalytic Activity for TiO2Nanomaterials by Codoping with Zinc and Sulfur

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Qianzhi Xu ◽  
Xiuying Wang ◽  
Xiaoli Dong ◽  
Chun Ma ◽  
Xiufang Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sunlight Irradiation ◽  
X Ray ◽  
Transmission Electron ◽  
Photoinduced Charge

S/Zn codoped TiO2nanomaterials were synthesized by a sol-gel method. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the morphology, structure, and optical properties of the prepared samples. The introduction of Zn and S resulted in significant red shift of absorption edge for TiO2-based nanomaterials. The photocatalytic activity was evaluated by degrading reactive brilliant red X-3B solution under simulated sunlight irradiation. The results showed S/Zn codoped TiO2exhibited higher photocatalytic activity than pure TiO2and commercial P25, due to the photosynergistic effect of obvious visible light absorption, efficient separation of photoinduced charge carriers, and large surface area. Moreover, the content of Zn and S in the composites played important roles in photocatalytic activity of TiO2-based nanomaterials.

Surfactant-Assisted Solvothermal Synthesis and High Visible-Light-Induced Photocatalytic Activity of BiOBr Nanocomposite Photocatalyst

NANO ◽  
2016 ◽  
Vol 11 (01) ◽  
pp. 1650002 ◽  
Author(s):  
Jing Xu ◽  
Guogang Tang ◽  
Wei Liang ◽  
Dongyi Zhou ◽  
Changsheng Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Contaminants ◽  
High Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
One Pot ◽  
Photocatalytic Ability ◽  
Composite Microspheres ◽  
Surfactant Assisted

BiOCl/BiOBr composite microspheres were synthesized through a one-pot mixed surfactant-assisted solvothermal process. The morphology, crystal structure, surface area and photocatalytic activity of the as-prepared BiOCl/BiOBr composite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible diffuse reflectance spectroscopy. The photocatalytic ability of the as-prepared photocatalysts was evaluated using rhodamine B (RhB) as a target pollutant. The BiOCl/BiOBr composite exhibited much higher photocurrent intensity than pure BiOBr, BiOCl and other different components, which perfectly coincided with the enhanced photocatalytic activity for the degradation of RhB under visible light ([Formula: see text][Formula: see text]nm). Moreover, this novel and facile strategy to fabricate bismuth halide-based composite with high efficiency were widely used in other bismuth-based composite photocatalyst for removing organic contaminants in wastewater.

scholarly journals In Situ g-C3N4@Zno Nanocomposite: One-Pot Hydrothermal Synthesis and Photocatalytic Performance under Visible Light Irradiation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lan Anh Luu Thi ◽  
Mateus Manuel Neto ◽  
Thang Pham Van ◽  
Trung Nguyen Ngoc ◽  
Tuyet Mai Nguyen Thi ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
High Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Irradiation ◽  
Nitrate Hexahydrate ◽  
One Pot ◽  
Simple Method

In situ g-C3N4@ZnO nanocomposites (with 0, 1, 3, 5, and 7 wt.% of g-C3N4 in nanocomposite) were synthesized via a one-pot hydrothermal method using precursors of urea, zinc nitrate hexahydrate, and hexamethylenetetramine. The g-C3N4@ZnO nanocomposites were characterized by X-ray diffraction, scanning electron microscope, diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The photocatalyst activity of g-C3N4@ZnO nanocomposites was evaluated via methylene blue degradation experiment under visible light irradiation. The g-C3N4@ZnO nanocomposites showed an enhancement in photocatalytic activity in comparison to pure ZnO which increased with the g-C3N4 content (1, 3, 5, and 7 wt.%) in nanocomposites. The photocatalytic activity reached the highest efficiency of 96.8% when the content of g-C3N4 was 7.0 wt.%. Nanocomposite having 7.0 wt.% of g-C3N4 also showed good recyclability with degradation efficiency higher than 90% even in the 4th use. The improvement of photocatalytic activity could be attributed to the adsorption ability and effective separation of electron-hole pairs between g-C3N4 and ZnO. This work implies a simple method to in situ prepare the nanocomposite material of g-C3N4 and semiconductors oxide for photocatalyst applications with high efficiency and good recyclability.

Synthesis and Photocatalytic Activity of Yb Doped TiO2 Nanoparticles under Visible Light

2009 ◽  
Vol 5 ◽  
pp. 193-200 ◽  
Author(s):  
Mou Pal ◽  
Umapada Pal ◽  
R. Silva Gonzalez ◽  
E. Sanchez Mora ◽  
P. Santiago
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Diffuse Reflectance Spectroscopy ◽  
Dark Field ◽  
Energy Dispersion Spectroscopy ◽  
Transmission Electron ◽  
Degradation Rates ◽  
Annular Dark Field ◽  
Average Size

Developing new semiconductor materials with improved photocatalytic activity is a promising technology for the remedy of environmental pollution. Here we report on the synthesis of Yb containing TiO2 nanoparticles and their catalytic activity under visible light. Highly monodispersed, spherical TiO2 and TiO2 :Yb nanoparticles of 27- 40 nm size range were prepared through controlled hydrolysis of titanium tetrabutoxide (TTB) and characterized by X-ray diffraction (XRD), energy dispersion spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), high angle annular dark field (HAADF), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) techniques. Average size of the nanoparticles was found to decrease with the increase of Yb doping concentration. The photocatalytic activity of Yb doped TiO2 was evaluated by measuring the degradation rates of methylene blue (MB) under UV and visible lights. Doping with ytterbium ions enhanced significantly the photocatalytic activity of TiO2 nanoparticles for MB oxidation under visible light.

scholarly journals The Contrastive Research in the Photocatalytic Activity of BiOBr Synthesized by Different Reactants

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Wang Ling-Li ◽  
Ma Wan-Hong ◽  
Wang Shu-Lian ◽  
Zhang Yu ◽  
Jia Man-Ke ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Active Species ◽  
X Ray Diffraction ◽  
Toc Removal ◽  
Transmission Electron ◽  
Uv Visible ◽  
Adsorption Desorption

BiOBr nanoplates, marked asα-BiOBr andβ-BiOBr, were synthesized via hydrothermal method using cetylpyridinium bromide (CPB) and NaBr as reactants, respectively. X-Ray Diffraction (XRD), transmission electron microscope (TEM), N2adsorption/desorption, UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and cyclic voltammetry (CV) were employed to characterize the obtained BiOBr. The results showed thatα-BiOBr andβ-BiOBr can absorb visible light and both the band gaps of them were about 2.76 eV. Under visible light irradiation, the photodegradation of organic dye sulforhodamine (SRB) and salicylic acid (SA) usingα-BiOBr andβ-BiOBr as the catalysts was carried out. The reaction kinetic constants of the degradation of SRB byα-BiOBr andβ-BiOBr were 0.00602 min−1and 0.0047 min−1, respectively, which indicated that the photocatalytic activity ofα-BiOBr was higher than that ofβ-BiOBr. The UV-Vis DRS and total organic carbon (TOC) were also monitored, and the TOC removal rate ofα-BiOBr andβ-BiOBr was 86% and 48%, respectively. At the same time, hydrogen peroxide (H2O2) and active radicals were measured and analyzed, which showed that the main active species wasOH∙during the photocatalytic reaction.

Improved visible-light photocatalytic activity of sodium tantalum oxide via biomass-derived silk fibroin doping

2018 ◽  
Vol 89 (7) ◽  
pp. 1332-1339
Author(s):  
Yehua Sun ◽  
Yuzhuo Luo ◽  
Yaofeng Zhu ◽  
Yaqin Fu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Silk Fibroin ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
X Ray ◽  
Transmission Electron

Biomass-derived silk fibroin (SF)-doped NaTaO3 catalysts were successfully synthesized by a simple hydrothermal process using SF as the dopant. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) analyses. The samples were tested as photocatalysts in the degradation of methylene blue under UV and visible light. XRD results showed the monoclinic structure of NaTaO3 lacking significant structural changes after anion doping. SEM and TEM images revealed the nanocubic morphology of the samples, the crystal particle sizes of which were about 100–300 nm. The XPS spectrum showed the peak of Ta4p3&N1s, indicating the combination of N and Ta. The UV-vis DRS results of the samples revealed a cut-off edge that red shifted from 315 nm of the pure NaTaO3 to 324 nm of the SF-doped counterpart. SF doping helped narrow the band gap and rendered the prepared sample sensitive to visible light. Under UV and visible-light irradiation, SF-doped NaTaO3 exhibited higher photocatalytic activity than that the undoped compound. SF-doped NaTaO3 samples also exhibited excellent stability during the recycling photocatalytic process.

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