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.

scholarly journals Preparation of g-C3N4/MoS2 Composite Material and Its Visible Light Catalytic Performance

2021 ◽  
Author(s):  
Yu Fan ◽  
Yan-ning Yang ◽  
Chen Ding
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.

scholarly journals Synthesis of C-N-S-Tridoped TiO2 from Vietnam Ilmenite Ore and Its Visible Light-Driven-Photocatalytic Activity for Tetracyline Degradation

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Nguyen Thi Lan ◽  
Vo Hoang Anh ◽  
Hoang Duc An ◽  
Nguyen Phi Hung ◽  
Dao Ngoc Nhiem ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
Photocatalytic Decomposition ◽  
Raman Scattering Spectroscopy ◽  
X Ray ◽  
Visible Light Driven

In this study, C-N-S-tridoped TiO2 composite was fabricated from TiO2 prepared from ilmenite ore and thiourea by means of hydrothermal method. The obtained material was characterized by X-ray diffraction, Raman scattering spectroscopy, UV-Vis diffuse reflectance spectroscopy, nitrogen adsorption-desorption isotherms, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that C-N-S-tridoped TiO2 material has a large specific surface area, showing good photocatalytic activity on the degradation of antibiotic tetracycline in visible light region. The study on the mechanism of tetracycline photodegradation using the liquid chromatography with mass spectrometry was performed. It was found that tetracycline has been degraded over C-N-S-tridoped TiO2 catalyst into many different intermediates which can eventually be converted into CO2 and H2O. The kinetics of photocatalytic decomposition of tetracycline were investigated. In addition, the obtained material could catalyze well the degradation of other antibiotics (ciprofloxacin and chloramphenicol) and dyes (rhodamine-B, methylene blue, and organe red). The catalyst was stable after five recycles with slight loss of catalytic activity, which indicates great potential for practical application of C-N-S-tridoped TiO2 catalyst in treatment of wastewater containing tetracycline in particular or antibiotics in general.

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.

scholarly journals Fabrication of Bi-DopedTiO2Spheres with Ultrasonic Spray Pyrolysis and Investigation of Their Visible-Light Photocatalytic Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jianhui Huang ◽  
Wahkit Cheuk ◽  
Yifan Wu ◽  
Frank S. C. Lee ◽  
Wingkei Ho
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Spray Pyrolysis ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Ultrasonic Spray Pyrolysis ◽  
X Ray ◽  
Ultrasonic Spray ◽  
Doped Titania

Bismuth-doped TiO2submicrospheres were synthesized by ultrasonic spray pyrolysis. The prepared bismuth-doped titania was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). Aqueous photocatalytic activity was evaluated by the decomposition of methyl orange under visible-light irradiation. The results indicate that doping of bismuth remarkably affects the phase composition, crystal structure, and the photocatalytic activity. The sample with 2% Bi exhibits the optimum photocatalytic activity.

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.

scholarly journals Self-Assembly of TiO2/CdS Mesoporous Microspheres with Enhanced Photocatalytic Activity via Hydrothermal Method

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sujing Yu ◽  
Juncheng Hu ◽  
Jinlin Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Hydrothermal Method ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Mesoporous Microspheres

Self assembly of TiO2/CdS mesoporous microspheres was synthesized via hydrothermal method. The samples were characterized by X-ray powder diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), energy-dispersive spectroscopy analysis (EDS), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectra (PL). The as-synthesized TiO2/CdS mesoporous microspheres showed superior photocatalytic activity for the degradation of RhB under either visible light or simulated sunlight irradiation; the 10 wt% TiO2/CdS sample showed the best performance. Moreover, this catalyst showed improved stability, and the activity did not decrease significantly after four recycles. The heterojunction between TiO2and CdS may be favorable for the transport of photoinduced electrons from CdS to TiO2. In addition, the mesoporous structure could increase the utilization of light energy and facilitate the diffusion of reactants and products during the photocatalytic reaction.

scholarly journals Facile Synthesis of Heterojunctioned ZnO/Bi2S3 Nanocomposites for Enhanced Photocatalytic Reduction of Aqueous Cr(VI) under Visible-Light Irradiation

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 624 ◽  
Author(s):  
Xiaoya Yuan ◽  
Xue Wu ◽  
Zijuan Feng ◽  
Wen Jia ◽  
Xuxu Zheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
High Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Structured Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Facile Solvothermal Method

Heterojunctioned ZnO/Bi2S3 nanocomposites were prepared via a facile solvothermal method. The obtained photocatalysts were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), and Photoelectrochemical and Photoluminescence spectroscopy (PL), respectively. The results showed that ZnO/Bi2S3 composites exhibited the sandwiched-like structure, where ZnO nanoparticles were randomly embedded between Bi2S3 nanoflakes. The performance of photocatalytic Cr(VI) reduction under visible light indicated that ZnO/Bi2S3 composites exhibited high-efficiency photocatalytic activity in comparison with either Bi2S3 or ZnO. The 5%-ZnO/Bi2S3 photocatalyst removed 96% of Cr(VI) within 120 min at 20 mg/L initial concentration of Cr(VI). The enhanced performance of ZnO/Bi2S3 photocatalysts could be ascribed to the increased light harvesting and the effective separation and transfer of the photogenerated charge carriers across the heterojunction interface of the ZnO/Bi2S3 composite. This work could pave the way for the design of new hetero-structured materials and has great potential in environmental remediation.

scholarly journals Synthesis of Al-MCM-41@Ag/TiO2 Nanocomposite and Its Photocatalytic Activity for Degradation of Dibenzothiophene

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xuan Nui Pham ◽  
Tuan Dat Pham ◽  
Ba Manh Nguyen ◽  
Hoa Thi Tran ◽  
Dinh Trong Pham
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
High Surface ◽  
Sol Gel ◽  
High Catalytic Activity ◽  
X Ray ◽  
Mcm 41

Mesoporous Al-MCM-41@Ag/TiO2 nanocomposites were synthesized successfully by combining the sol-gel method and hydrothermal treatment, using titanium isopropoxide (TTIP), AgNO3, and Vietnamese bentonite as precursors of Ti, Ag, and Si, respectively. The synthesized materials were well characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption isotherm measurements, energy dispersive X-ray spectroscopy (EDX), UV-visible diffuse reflectance spectroscopy (UV-Vis/DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was evaluated by the photodegradation of dibenzothiophene (DBT) under both UV and visible light irradiation. MCM-41@Ag/TiO2 catalyst exhibited high catalytic activity for the oxidative desulfurization (ODS) of DBT reaching almost 100% conversions at 50°C after 2 h under UV and visible light irradiations. The significant enhanced degradation of DBT over Al-MCM-41@Ag/TiO2 might be due to the synergy effects of high surface area of MCM-41, well-distributed TiO2 anatase, and reduced electron-hole recombination rates due to the dispersion of Ag nanoparticles.

scholarly journals Synthesis and Characterization of Pyrochlore Bi2Sn2O7Doping with Praseodymium by Hydrothermal Method and Its Photocatalytic Activity Study

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Weicheng Xu ◽  
Guangyin Zhou ◽  
Jianzhang Fang ◽  
Zhang Liu ◽  
YunFang Chen ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Adsorption Desorption

Praseodymium doped Bi2Sn2O7(BSO), as a visible-light responsive photocatalyst, was prepared by a hydrothermal method with different dopant contents. The as-prepared photocatalysts were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N2adsorption-desorption isotherm, X-ray photoelectron spectroscopy analysis (XPS), and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of prepared catalysts was evaluated by the degradation of Rhodamine Bextra (RhB) and 2,4-dichlorophenol (2,4-DCP) in aqueous solution under visible light irradiation. It was found that Pr doping inhibited the growth of crystalline size and the as-prepared materials were small in size (10–20 nm). In our experiments, Pr-doped BSO samples exhibited enhanced visible-light photocatalytic activity compared to the undoped BSO, and the optimal dopant amount of Pr was 1.0 mol% for the best photocatalytic activity. On the basis of the calculated PL spectra, the mechanism of enhanced photocatalytic activity has been discussed.

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.

Sign in / Sign up

Export Citation Format

Share Document