scholarly journals Synthesis of Highly Active Heterostructured Al2TiO5/TiO2 Photocatalyst in a Neutral Medium

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Nguyen D. Trung ◽  
Nguyen Tri ◽  
Phan H. Phuong ◽  
Ha C. Anh
Keyword(s):  
Electron Microscopy ◽  
Removal Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Neutral Medium ◽  
Airflow Rate ◽  
Step Method ◽  
X Ray ◽  
Photodegradation Efficiency

In this work, heterostructured catalyst Al2TiO5/TiO2 (ATO/Ti) was synthesized by a two-step method: low-temperature sol-gel process along with hydrothermal treatment in a neutral medium. Characteristics of the fabricated catalyst were analyzed by various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption, UV-Vis diffuse reflectance spectroscopy, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and the point of zero charges. The content of ATO strongly affected the activity of ATO/Ti catalysts for photocatalytic degradation of cinnamic acid (CA). The catalyst, in which 33% TiO2 was replaced by ATO (33ATO/Ti), exhibited the highest activity for the removal of CA. Compared with the bare titanium oxide synthesized in water (TiO2(w)) as well as Al2TiO5 (ATO), the hybrid 33ATO/Ti catalyst exhibited the enhanced photocatalytic activity in the CA degradation under ultraviolet light. The enhancement in the catalytic activity of ATO/Ti could be related to the increase of the specific surface area and the reduction of bandgap energy obtained from the hybridization of TiO2(w) and ATO. The factors as the catalyst dosage ( C cat ), the airflow rate ( Q air ), and the solution initial pH (pH) affected the CA removal efficiency were studied on 33ATO/Ti catalyst. The optimum condition for photodegradation efficiency of CA was found to be at C cat = 0.75   g L − 1 , Q air = 0.3   Lmi n − 1 , and pH = 3.8 . The highest 60-minute removal efficiency of CA reached 77.1% on 33ATO/Ti compared with 67.1% and 30.4% on TiO2(w) and on ATO, respectively. The recyclability of the 33ATO/Ti was also measured at the optimal parameters. The results showed that, compared with TiO2, the hybrid catalyst was easier to recover and reuse, and its activity decreased by 35% after 6 continuous cycles.

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 Fabrication of ZnS-Bi-TiO2Composites and Investigation of Their Sunlight Photocatalytic Performance

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Xuewei Dong ◽  
Fan Zhang ◽  
Chuan Rong ◽  
Hongchao Ma
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Kinetic Constant ◽  
Sol Gel ◽  
Visible Region ◽  
Xenon Lamp ◽  
X Ray ◽  
Photodegradation Efficiency ◽  
Photogenerated Electrons ◽  
Transmission Electron

The ZnS-Bi-TiO2composites were prepared by the sol-gel method and were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). It is found that the doped Bi as Bi4+/Bi3+species existed in composites, and the introducing of ZnS enhanced further the light absorption ability of TiO2in visible region and reduced the recombination of photogenerated electrons and holes. As compared to pure TiO2, the ZnS-Bi-TiO2exhibited enhanced photodegradation efficiency under xenon lamp irradiation, and the kinetic constant of methyl orange removal with ZnS-Bi-Ti-0.005 (0.0141 min−1) was 3.9 times greater than that of pure TiO2(0.0029 min−1), which could be attributed to the existence of Bi4+/Bi3+species, the ZnS/TiO2heterostructure.

scholarly journals Photocatalytic performance of Ag2S/ZnO/ZnS nanocomposites with high visible light response prepared via microwave-assisted hydrothermal two-step method

2018 ◽  
Vol 78 (8) ◽  
pp. 1802-1811 ◽  
Author(s):  
Jiwei Huang ◽  
Changlong Yang ◽  
Qiang Song ◽  
Dongxue Liu ◽  
Li Li
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Response ◽  
Light Sources ◽  
Step Method ◽  
X Ray ◽  
Microwave Assisted ◽  
Visible Light Response

Abstract A series of different ratios of Ag2S/ZnO/ZnS nanocomposites with visible light response were prepared by a microwave-assisted hydrothermal two-step method, whose composition, crystalline structure, morphology and surface physicochemical properties were well-characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis/DRS), photoluminescence spectrum (PL), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and N2 adsorption–desorption measurements. Results showed that as-composites mainly consisted of ZnS crystal phase, whose grain size increased obviously compared with non Ag2S samples. At the same time, due to the introduction of narrow band gap Ag2S, the synthesized composite can effectively increase the visible optical absorption of ZnO/ZnS composites. Among them, 1% Ag2S/ZnO/ZnS showed a mixed structure of nano-line and nano-particle, of which BET value increased significantly, and the morphology was more excellent. Photocatalytic activities of a series of Ag2S/ZnO/ZnS composites under different light sources were studied using methyl orange as a model molecule, and 1% Ag2S/ZnO/ZnS was taken as the best one. Meanwhile, 1% Ag2S/ZnO/ZnS also showed a good degradation effect on other dyes with different structures, and its degradation efficiency did not change significantly after three cycles, showing certain stability. In addition, composites with Ag2S loading of 1% possessed the highest hydrogen production ability of photolysis water, indicating that the introduction of Ag2S had significantly enhanced the catalytic performance.

scholarly journals Controllable Synthesis and Photocatalytic Activity of Nano-BiOBr Photocatalyst

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xiaoyang Wang ◽  
Fuchun Zhang ◽  
Yanning Yang ◽  
Yu Zhang ◽  
Lili Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Deionized Water ◽  
Bandgap Energy ◽  
Controllable Synthesis ◽  
X Ray ◽  
Glycol Solution ◽  
Scanning Electron

Nano-BiOBr photocatalysts were successfully prepared by hydrothermal synthesis using the ethylene glycol solution. The nano-BiOBr photocatalysts were characterized and investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), photoluminescence (PL), and UV-vis diffuse reflectance spectroscopy (UV-Vis DRS), and the catalytic ability toward photodegradation of rhodamine B (RhB) was also explored. The results showed that the crystallinity of the nano-BiOBr photocatalyst decreased with the increase of the concentration, while it increased with the amount of the applied deionized water. The morphology of the nano-BiOBr photocatalyst changed from microspheres to cubes and then to a mixture of microspheres and flakes with the increasing of the concentration and from microspheres to flakes with the addition of the deionized water. The results indicated that the concentration and solvents have an essential influence on the bandgap energy values of the nano-BiOBr photocatalyst, and photocatalyst showed an excellent photocatalyst activity toward photodegradation of RhB. The degradation yields of photocatalyst decreased with the increase of the concentration and increased with the addition of the deionized water. PL intensity of photocatalyst increased with the increase of the concentration and weakened with the addition of the deionized water.

scholarly journals Sulfur/Gadolinium-Codoped TiO2Nanoparticles for Enhanced Visible-Light Photocatalytic Performance

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Eric S. Agorku ◽  
Bhekie B. Mamba ◽  
Avinash C. Pandey ◽  
Ajay K. Mishra
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Anatase Phase ◽  
Sol Gel ◽  
Indigo Carmine ◽  
Great Influence ◽  
Energy Dispersive ◽  
X Ray

A series of S/Gd3+-codoped TiO2photocatalysts were synthesized by a modified sol-gel method. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy, scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM)/energy-dispersive spectroscopy (EDS). Laboratory experiments with Indigo Carmine chosen as a model for organic pollutants were used to evaluate the photocatalytic performance of S/Gd3+-codoped TiO2under visible-light with varying concentrations of Gd3+ions in the host material. XRD and Raman results confirmed the existence of anatase phase TiO2with particle size ranging from 5 to 12 nm. Codoping has exerted a great influence on the optical responses along with red shift in the absorption edge. S/Gd3+-codoped TiO2showed significant visible-light induced photocatalytic activity towards Indigo Carmine dye compared with S-TiO2or commercial TiO2. TiO2-S/Gd3+(0.6% Gd3+) degraded the dye (ka= 5.6 × 10−2 min−1) completely in 50 min.

scholarly journals SYNTHESIS, CHARACTERIZATION AND PHOTOACTIVITY EVALUATION OF NITROGEN DOPED TITANIUM DIOXIDE ON METHYLENE BLUE DYE DEGRADATION

2020 ◽  
Vol 4 (3) ◽  
pp. 148-153
Author(s):  
Moses Titus Yilleng ◽  
Moses Sunday ◽  
Doctor Stephen
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Titanium Dioxide ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Uv Light ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Blue Dye ◽  
Photodegradation Efficiency

Titanium dioxide has proven to be one of the most promising heterogeneous catalyst. This work explores the photocatalytic activity of modified titanium dioxide. Nitrogen was incorporated into mesoporous TiO2 using Sol-gel method. The N-TiO2 was characterized using X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) thermogravimetric analysis (TGA), and U-Vis diffuse reflectance spectroscopy (DRS). 1%wtN-TiO2 expresses the highest photoactivity in UV light compared to 3%wtN-TiO2 and 5%wt N-TiO2 respectively. The photodegradation efficiency of the catalyst follows the following trend 1%wtN-TiO2 >3%wtN-TiO2 >5%wtN-TiO2>PURE-TiO2. The results obtained from the kinetics investigation shows the following trends 1%wtN-TiO2 is 0.049 s-1, 3%wtN-TiO2 is 0.0289 s-1, 5%wtN-TiO2 is 0.0143 s-1, and the PURE-TiO2 is 0.0118 s-1. The consistency in the rate constant values of the phodegradation of methylene blue; it clearly showed that the reaction follows a pseudo-first order kinetics.

Synthesis of Eu-Doped Bi2O3/CeO2 Composite with Enhanced Photocatalytic Activity by a Facile Sol–Gel–Calcination Route

2015 ◽  
Vol 68 (10) ◽  
pp. 1562 ◽  
Author(s):  
Fengjun Zhang ◽  
Guosheng Xiao ◽  
Wei Lu ◽  
Tianye Wang ◽  
Limin Xuan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible ◽  
Scanning Electron

Eu-Doped Bi2O3/CeO2 composites were successfully synthesized by a facile sol–gel–calcination route. The as-prepared composites were prepared with different molar ratios of Bi/Ce/Eu by the sol–gel route, and then calcined at 500°C for 2 h. The photocatalytic efficiencies of all composites were tested by degradation of methyl orange (MO) under visible light irradiation. The result suggested that the best composite is the one that was prepared with a Bi/Ce/Eu mole ratio of 8 : 8 : 1, and achieved a MO degradation rate of nearly 98.5 % within 2 h of irradiation. The as-prepared composites were characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The X-ray diffraction and scanning electron microscopy results suggested that Eu doping may have led to some lattice distortion and particle aggregation that enhanced the photocatalytic activity of the photocatalyst. The UV-visible diffuse reflectance spectroscopy and photoluminescence spectroscopy results showed that Eu-doped Bi2O3/CeO2 exhibited higher visible light response properties and enhanced separation of the photogenerated electron–hole pairs, which is the main reason for the higher photocatalytic activity. In general, this study could provide a facile route to synthesize Eu-doped Bi2O3/CeO2 composites with enhanced photocatalytic activity by a sol–gel–calcination route for environmental purification.

scholarly journals Improved Photocatalytic Performance of a Novel Fe3O4@SiO2/Bi2SiO5Hierarchical Nanostructure with Magnetic Recoverability

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xinxin Zhang ◽  
Xiaoli Dong ◽  
Baiyu Leng ◽  
Hongchao Ma ◽  
Xiufang Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Hierarchical Architecture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photodegradation Efficiency ◽  
Activity Loss ◽  
Magnetic Recoverability ◽  
Red Dye

Magnetic Fe3O4@SiO2/Bi2SiO5composites with a novel hierarchical nanostructure were synthesized by sol-gel and hydrothermal methods and were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance spectroscopy (UV-vis DRS). It was found that the introduction of Fe3O4@SiO2could turn the morphology of Bi2SiO5from close-grained slab to hollow hierarchical architecture with fabric-structure. The Fe3O4@SiO2/Bi2SiO5composite showed enhanced photodegradation efficiency for the degradation of reactive brilliant red dye (X-3B) in aqueous solution under simulated sunlight irradiation, as compared with that of commercial P25. In addition, the Fe3O4@SiO2/Bi2SiO5composite exhibited good magnetic recoverability and excellent photocatalytic stability (no obvious activity loss after recycling tests).

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 Effect of Benzalkonium Chloride on Properties of Zinc Oxide Nanoparticles Synthesized through Sol-Gel Technique

2020 ◽  
Vol 4 (1) ◽  
pp. 41
Author(s):  
Hwda Ghafur Rauf ◽  
Madzlan Aziz ◽  
Sattar Ibrahim Kareem
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Cationic Surfactant ◽  
Benzalkonium Chloride ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Zno Nanostructures ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

In the present study, to synthesize controllable sized metal oxide particles, benzalkonium chloride (BAK) as cationic surfactant was added to zinc oxide (ZnO) nanostructures synthesis at room temperature using sol–gel method. The effect of cationic surfactant BAK concentrations, on the optical properties, size, and morphology of ZnO nanoparticles synthesized through sol–gel method was studied. The characterization of ZnO nanostructures was occurred using transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet–visible near infrared (UV-Vis) spectrophotometer, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). ZnO nanostructures shape and size were revealed by SEM and TEM. The hexagonal (wurtzite structure) of ZnO was confirmed by an X-ray diffractogram. The bandgap energy of the prepared ZnO samples was determined by UV-Vis spectrophotometer. FTIR analyzed the presence of functional groups.

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