scholarly journals Novel Ternary Heterogeneous Reduction Graphene Oxide (RGO)/BiOCl/TiO2 Nanocomposites for Enhanced Adsorption and Visible-Light Induced Photocatalytic Activity toward Organic Contaminants

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2529 ◽  
Author(s):  
Zhanxin Jing ◽  
Xiangyi Dai ◽  
Xueying Xian ◽  
Qiongshan Zhang ◽  
Huojiao Zhong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Organic Contaminants ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
Reaction System ◽  
Cost Effective ◽  
Active Species ◽  
X Ray

Herein, we describe a simple and cost-effective design for the fabrication of a novel ternary RGO/BiOCl/TiO2 nanocomposites through a simple hydrothermal process. The prepared nanocomposites were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and N2 adsorption–desorption analysis. Organic contaminants—such as methylene blue (MB), methyl orange (MO), rhodamine B (RhB) and amido black-10B (AB-10B)—were employed as the target pollutants to evaluate the adsorption capacity and photocatalytic activity of RGO/BiOCl/TiO2 nanocomposites. From experimental data, it was also found that the amount of TiO2 impressed the photocatalytic performance, and the nanocomposites with 10% of TiO2 showed the best photocatalytic activity. The improved photocatalytic performance may be mainly due to the narrow band gap, and the charge separation and migration of RGO. Moreover, good recyclability was obtained from RGO/BiOCl/TiO2 nanocomposites, and scavenger tests indicated that photogenerated holes were the main active species in the reaction system. Therefore, the prepared RGO/BiOCl/TiO2 nanocomposites have broad applications foreground in pollutants purification.

Hydrothermal Fabrication of BiVO4/ Diatomite Composite Photocatalysts and their Photocatalytic Performance

2021 ◽  
Vol 904 ◽  
pp. 350-357
Author(s):  
Tian Qing Cui ◽  
Jun Feng Ma ◽  
Qun Si Wang ◽  
Qi Zhou ◽  
Dong Bin Tang
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Hydrothermal Process ◽  
Precursor Solution ◽  
Chelating Agent ◽  
High Porosity ◽  
X Ray ◽  
Composite Photocatalysts ◽  
Vis Spectroscopy

A hydrothermal process was proposed to prepare BiVO4/ diatomite composite photocatalysts, where BiVO4 was grown from a precursor solution containing diatomite, and EDTA used as a chelating agent to prevent the precipitation of precursor solution compositions on diatomite before hydrothermal treatment. The effect of some processing parameters like diatomite percentage and Ag-loaded amount on their photocatalytic performance were also investigated in detail by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), BET, and UV‐Vis spectroscopy. The results show that BiVO4/ diatomite composite photocatalysts can be successfully prepared at 160 °C for the duration of 3h by the hydrothermal process. The diatomite has two significant impacts on their photocatalytic performance: (1) enhancing the dispersion of BiVO4 crystallites due to its high porosity and specific surface area to favor their photocatalytic performance, and (2) having a light screening effect to incident visible light to decrease their photocatalytic activity. Appropriately incorporating diatomite could improve their photocatalytic performance, but the overuse of diatomite would reduce that. Similarly, depositing Ag could effectively improve their photocatalytic activity because of its good light absorption and photosensitive characteristics, but excessive addition would result in their decrease since the overuse of Ag would also promote the electron-hole recombination.

scholarly journals AgBr/(Sr0.6Bi0.305)2Bi2O7 Heterostructured Composites: Fabrication, Characterization, and Significantly Enhanced Photocatalytic Activity

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 394 ◽  
Author(s):  
Xinling Wang ◽  
Di Zhu ◽  
Yan Zhong ◽  
Dianhui Wang ◽  
Chaohao Hu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Precipitation Method ◽  
Light Illumination ◽  
X Ray ◽  
Transmission Electron ◽  
Pyrochlore Type

The pyrochlore-type (Sr0.6Bi0.305)2Bi2O7 (SBO) containing Bi3+ and Bi5+ mixed valent states was first investigated as a photocatalyst in our very recent work. To further improve the photocatalytic performance, AgBr/SBO heterostructured composites were synthesized by using a deposition-precipitation method. The characterization of phase structure, morphology, microstructure, elemental composition, and optical properties of the obtained products were performed using X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM)TEM, X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of samples was evaluated by degrading methylene blue under visible light illumination. AgBr/SBO composites possess high stability and significantly enhanced photocatalytic performance. The improvement of photocatalytic activity is due to the enhanced light absorption and the separation of photoinduced electrons and holes on the interface of AgBr/SBO heterostructured composites.

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.

Fabrication and Photocatalytic Performance of Ag/ZnO

2011 ◽  
Vol 396-398 ◽  
pp. 854-857 ◽  
Author(s):  
Zheng Hua Xiao ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Wei Hu
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Methyl Orange Solution ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Orange Solution

It has been found that the photocatalytic activity of ZnO toward the decolorization of Methyl Orange solution can be greatly improved by loading Ag on the surface of ZnO using a photodeposition method. The photocatalysts were characterized by X-ray diffraction(XRD), UV-Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy(XPS), respectively. 0.5%Ag/ZnO demonstrates 2.13 times the photocatalytic activity of pure ZnO.

A new core–shell Z-scheme heterojunction structured La(OH)3@In2S3 composite with superior photocatalytic performance

2021 ◽  
Vol 127 (2) ◽  
Author(s):  
Shuting Hu ◽  
Junfeng He ◽  
Fuming Chen ◽  
Bin Liu ◽  
Wangjian zhai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Electrochemical Impedance ◽  
Cost Effective ◽  
Active Species ◽  
X Ray ◽  
Methylene Orange ◽  
Photodegradation Rate ◽  
Redox Ability

AbstractConstructing Z-scheme heterojunction photocatalyst with strong redox ability to make for enhanced photocatalytic performance and efficient charge separation is extremely attractive but still underdeveloped. Herein, a Z-scheme heterojunction structured La(OH)3@In2S3 composite (labeled by “LIS”) with photocatalytic for the methylene orange (MO) degradation under simulated light irradiation has been developed. The as-prepared LIS, together with commercial La(OH)3 and pure In2S3 fabricated with the identical processing method and starting materials as those of LIS, was characterized by X-ray diffraction, UV–vis diffuse reflectance spectra, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra and electrochemical impedance spectroscopy. The results show the heterojunction of La(OH)3/In2S3 has prolonged the lifetime of the photo-generated carriers. The photocatalytic activity test shows that over only a small amount (0.02 g in 100 ml MO) of LIS, the photodegradation rate of 95% toward MO can be obtained in 90 min, which is about 3.4 times higher than that over pure In2S3. The active species trapping experiments indicate that there were four active species playing roles in photodegradation as the following order: e– = ∙OH < h+ < ∙O2–. A mechanism of Z-scheme heterojunction was proposed and well explained the enhanced photocatalytic performance. This work provides a new cost-effective photocatalyst with high photocatalytic properties.

scholarly journals Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Component Part ◽  
Energy Yield ◽  
Mechanical Agitation ◽  
X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

scholarly journals Study of the Effect of TiO2 Layer on the Adsorption and Photocatalytic Activity of TiO2-MoS2 Heterostructures under Visible-Infrared Light

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
N. Cruz-González ◽  
O. Calzadilla ◽  
J. Roque ◽  
F. Chalé-Lara ◽  
J. K. Olarte ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
High Photocatalytic Activity ◽  
Infrared Light ◽  
Polluted Water ◽  
Light Spectrum ◽  
X Ray

In the last decade, the urgent need to environmental protection has promoted the development of new materials with potential applications to remediate air and polluted water. In this work, the effect of the TiO2 thin layer over MoS2 material in photocatalytic activity is reported. We prepared different heterostructures, using a combination of electrospinning, solvothermal, and spin-coating techniques. The properties of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and X-ray photoelectron spectroscopy (XPS). The adsorption and photocatalytic activity were evaluated by discoloration of rhodamine B solution. The TiO2-MoS2/TiO2 heterostructure presented three optical absorption edges at 1.3 eV, 2.28 eV, and 3.23 eV. The high adsorption capacity of MoS2 was eliminated with the addition of TiO2 thin film. The samples show high photocatalytic activity in the visible-IR light spectrum.

scholarly journals Study on Synthesis and Photocatalytic Activity of Porous Titania Nanotubes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Huang Liu ◽  
Yanhua Zhang ◽  
Hongtao Yang ◽  
Wei Xiao ◽  
Lanlan Sun
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Filter Paper ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Cellulose Nanofibers ◽  
Titania Nanotubes ◽  
Tetrabutyl Titanate ◽  
X Ray ◽  
Porous Titania

Using the common natural cellulose substance (filter paper) and triblock copolymer (Pluronic P123) micelles as dual templates, porous titania nanotubes with enhanced photocatalytic activity have been successfully synthesized through sol-gel methods. Firstly, P123 micelles were adsorbed onto the surfaces of cellulose nanofibers of filter paper, followed by hydrolysis and condensation of tetrabutyl titanate around these micelles to form titania layer. After calcination to remove the organic templates, hierarchical titania nanotubes with pores in the walls were obtained. The sample was characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). As compared with commercial P25 catalyst, the porous titania nanotubes prepared by this method displayed significantly enhanced photocatalytic activity for degrading methyl orange under UV irradiation. Within 10 minutes, the porous titania nanotubes are able to degrade over 70% of the original MO, while the value for the commercial Degussa P25 is only about 33%.

scholarly journals Hydrothermal Synthesis of Iodine-Doped Nanoplates with Enhanced Visible and Ultraviolet-Induced Photocatalytic Activities

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jiang Zhang ◽  
Zheng-Hong Huang ◽  
Yong Xu ◽  
Feiyu Kang
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Diffuse Reflectance Spectroscopy ◽  
Synergetic Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Photocatalytic Activities

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.

scholarly journals Photocatalytic Degradation of Estriol Using Iron-Doped TiO2 under High and Low UV-Irradiation

2018 ◽  
Author(s):  
Irwing M. Ramírez-Sánchez ◽  
Erick R. Bandala
Keyword(s):  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Uv Irradiation ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Bet Surface Area ◽  
Doped Tio2 ◽  
X Ray ◽  
Transmission Electron ◽  
Iron Doped

Iron Doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe3+) was in the lattice of TiO2 and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radical (&bull;OH) and estriol (E3) degradation. Fe-TiO2 materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO2 (zero-iron TiO2) and Aeroxide&reg; TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.

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