scholarly journals Non-Stacked γ-Fe2O3/C@TiO2 Double-Layer Hollow Nanoparticles for Enhanced Photocatalytic Applications under Visible Light

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 201
Author(s):  
Xun Sun ◽  
Xiao Yan ◽  
Huijuan Su ◽  
Libo Sun ◽  
Lijun Zhao ◽  
...  
Keyword(s):  
Visible Light ◽  
Double Layer ◽  
Carbon Matrix ◽  
Catalytic Performance ◽  
Utilization Efficiency ◽  
Excitation Wavelength ◽  
High Concentration ◽  
Light Region ◽  
Initial Charge ◽  
Photocatalytic Applications

Herein, a non-stacked γ-Fe2O3/C@TiO2 double-layer hollow nano photocatalyst has been developed with ultrathin nanosheets-assembled double shells for photodegradation phenol. High catalytic performance was found that the phenol could be completely degraded in 135 min under visible light, due to the moderate band edge position (VB at 0.59 eV and CB at −0.66 eV) of the non-stacked γ-Fe2O3/C@TiO2, which can expand the excitation wavelength range into the visible light region and produce a high concentration of free radicals (such as ·OH, ·O2−, holes). Furthermore, the interior of the hollow composite γ-Fe2O3 is responsible for charge generation, and the carbon matrix facilitates charge transfer to the external TiO2 shell. This overlap improved the selection/utilization efficiency, while the unique non-stacked double-layered structure inhibited initial charge recombination over the photocatalysts. This work provides new approaches for photocatalytic applications with γ-Fe2O3/C-based materials.

scholarly journals Doped ZnO Nanostructured and their application as photocatalytic: as Review

2021 ◽  
Vol 4 (1) ◽  
pp. 1-15
Author(s):  
Fadhela M. Hussein
Keyword(s):  
Visible Light ◽  
Energy Gap ◽  
Sol Gel ◽  
Chemical Vapor ◽  
Light Region ◽  
Methods Of Synthesis ◽  
Wet Chemical ◽  
Doped Zno ◽  
Light Absorbance ◽  
Photocatalytic Applications

There are two types of methods of synthesis of several different kinds of doped ZnO nanomaterials for photocatalytic applications, gas phase methods, include pulsed laser deposition and chemical vapor deposition and wet chemical methods such as sol–gel, electrospinning, hydrothermal, spray pyrolysis, thermomechanical .doping with metal ions is make local energies levels within the semiconductor energy gap, which results in prolongation of the light absorbance to the visible light region. Several studies have that metaldoped ZnO, such as N, S, and C, using Co, Fe, Cu, Eu, Ce, Ag, Mn, and Al and non-metal doping, ZnO to the reducing Energies and enhancement of photocatalytic behavior in the region of visible light.

Fabrication and Performance of Photocatalytic GaN Powders

2011 ◽  
Vol 222 ◽  
pp. 142-145 ◽  
Author(s):  
Takayuki Nakano ◽  
Masateru Hamada ◽  
Shunro Fuke
Keyword(s):  
Visible Light ◽  
High Temperatures ◽  
Group Iii Nitrides ◽  
Visible Light Region ◽  
Group Iii ◽  
Light Region ◽  
And Performance ◽  
Group Iii Nitride ◽  
Photocatalytic Applications ◽  
Photocatalytic Materials

Group-III nitrides are expected to be used in future photocatalytic materials. InGaN is expected to be used for photocatalytic applications in the visible light region. Photocatalytic materials are used primarily in coatings and powders, and powdered photocatalysts are expected to be formed from group-III nitride powders. In this study, we produced GaN powders by nitriding Ga precursors at high temperatures under an atmosphere of NH3. The photocatalytic characteristics of the GaN powder were dependent on nitrization temperature. In addition, the crystallinity of the GaN powders and the photocatalysis were rapidly improved at nitrization temperatures over 1000°C.

A visible light detector based on a heterojunction phototransistor with a highly stable inorganic CsPbIxBr3−x perovskite and In–Ga–Zn–O semiconductor double-layer

2019 ◽  
Vol 7 (45) ◽  
pp. 14223-14231 ◽  
Author(s):  
Hyun-Jae Na ◽  
Nam-Kwang Cho ◽  
Jintaek Park ◽  
Sung-Eun Lee ◽  
Eun Goo Lee ◽  
...  
Keyword(s):  
Visible Light ◽  
Double Layer ◽  
Optoelectronic Devices ◽  
Visible Light Region ◽  
Light Detector ◽  
Light Region ◽  
Sensing Performance

An all-inorganic heterojunction phototransistor with perovskite (CsPbIxBr3−x) and IGZO is introduced to enhance the sensing performance of optoelectronic devices and to expand the detecting range from the ultraviolet to the visible light region.

Superior co-catalysis by bimetallic nanostructure for TiO2 photocatalysis

2020 ◽  
Vol 01 ◽  
Author(s):  
Bonamali Pal ◽  
Anila Monga ◽  
Aadil Bathla
Keyword(s):  
Visible Light ◽  
Catalytic Performance ◽  
Transition Metal Catalysts ◽  
Core Shell ◽  
Structural Morphology ◽  
Tio2 Photocatalysis ◽  
Co Catalysts ◽  
Bimetallic Nanocomposites ◽  
Bimetallic Nanostructure ◽  
Bimetallic Nanostructures

Background:: Bimetallic nanocomposites have currently gained significant importance for enhanced catalytic applications relative to monometallic analogues. The synergistic interactions modified electronic and optical properties in the bimetallic (M1@M2) structural morphology e.g., core-shell /alloy nanostructures resulted in a better co-catalytic performance for TiO2 photocatalysis. Objective:: Hence, this article discusses the preparation, characterization, and co-catalytic activity of different bimetallic nanostructures namely, Cu@Zn, Pd@Au, Au@Ag, and Ag@Cu, etc. Method:: These bimetallic co-catalysts deposited on TiO2 possess the ability to absorb visible light due to surface plasmonic absorption and are also expected to display the new properties due to synergy between two distinct metals. As a result, they reveal the highest level of activity than the monometal deposited TiO2. Result:: Their optical absorption, emission, charge carrier dynamics, and surface structural morphology are explained for the improved photocatalytic activity of M1@M2 loaded TiO2 for the hydrogenation of certain organic compounds e.g., quinoline, crotonaldehyde, and 1,3-dinitrobenzene, etc. under UV/ visible light irradiation. Conclusion:: It revealed that the use of bimetallic core@shell co-catalyst for hydrogenation of important industrial organics by M1@M2-TiO2 nanocomposite demonstrates beneficial reactivity in many instances relative to conventional transition metal catalysts.

Green Synthesis of ZnO/Dy/NiO Heterostructures for Enhanced Photocatalytic Applications

2020 ◽  
Vol 1 (1) ◽  
pp. 30-36
Author(s):  
Shubha Jayachamarajapura Pranesh ◽  
Diwya Lanka
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Combustion Method ◽  
Hybrid Nanocomposites ◽  
Synthetic Dyes ◽  
Hybrid Nanostructure ◽  
Wide Range ◽  
Visible Light Active ◽  
Textile Industries ◽  
Photocatalytic Applications

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.

scholarly journals Insight into Active Centers and Anti-Coke Behavior of Niobium-Containing SBA-15 for Glycerol Dehydration

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 488
Author(s):  
Katarzyna Stawicka ◽  
Maciej Trejda ◽  
Maria Ziolek
Keyword(s):  
Coke Formation ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Silica Matrix ◽  
High Concentration ◽  
Active Centers ◽  
Acidic Sites ◽  
Glycerol Dehydration ◽  
Adsorption Desorption ◽  
Insight Into

Niobium containing SBA-15 was prepared by two methods: impregnation with different amounts of ammonium niobate(V) oxalate (Nb-15/SBA-15 and Nb-25/SBA-15 containing 15 wt.% and 25 wt.% of Nb, respectively) and mixing of mesoporous silica with Nb2O5 followed by heating at 500 °C (Nb2O5/SBA-15). The use of these two procedures allowed obtaining materials with different textural/surface properties determined by N2 adsorption/desorption isotherms, XRD, UV-Vis, pyridine, and NO adsorption combined with FTIR spectroscopy. Nb2O5/SBA-15 contained exclusively crystalline Nb2O5 on the SBA-15 surface, whereas the materials prepared by impregnation had both metal oxide and niobium incorporated into the silica matrix. The niobium species localized in silica framework generated Brønsted (BAS) and Lewis (LAS) acid sites. The inclusion of niobium into SBA-15 skeleton was crucial for the achievement of high catalytic performance. The strongest BAS were on Nb-25/SBA-15, whereas the highest concentration of BAS and LAS was on Nb-15/SBA-15 surface. Nb2O5/SBA-15 material possessed only weak LAS and BAS. The presence of the strongest BAS (Nb-25/SBA-15) resulted in the highest dehydration activity, whereas a high concentration of BAS was unfavorable. Silylation of niobium catalysts prepared by impregnation reduced the number of acidic sites and significantly increased acrolein yield and selectivity (from ca. 43% selectivity for Nb-25/SBA-15 to ca. 61% for silylated sample). This was accompanied by a considerable decrease in coke formation (from 47% selectivity for Nb-25/SBA-15 to 27% for silylated material).

scholarly journals Prediction of Band Gap Energy of Doped Graphitic Carbon Nitride Using Genetic Algorithm-Based Support Vector Regression and Extreme Learning Machine

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 411
Author(s):  
Taoreed O. Owolabi ◽  
Mohd Amiruddin Abd Rahman
Keyword(s):  
Genetic Algorithm ◽  
Visible Light ◽  
Band Gap ◽  
Carbon Nitride ◽  
Activation Function ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Support Vector ◽  
Learning Machine ◽  
Photocatalytic Applications

Graphitic carbon nitride is a stable and distinct two dimensional carbon-based polymeric semiconductor with remarkable potentials in organic pollutants degradation, chemical sensors, the reduction of CO2, water splitting and other photocatalytic applications. Efficient utilization of this material is hampered by the nature of its band gap and the rapid recombination of electron-hole pairs. Heteroatom incorporation due to doping alters the symmetry of the semiconductor and has been among the adopted strategies to tailor the band gap for enhancing the visible-light harvesting capacity of the material. Electron modulation and enhancement of reaction active sites due to doping as evident from the change in specific surface area of doped graphitic carbon nitride is employed in this work for modeling the associated band gap using hybrid genetic algorithm-based support vector regression (GSVR) and extreme learning machine (ELM). The developed GSVR performs better than ELM-SINE (with sine activation function), ELM-TRANBAS (with triangular basis activation function) and ELM-SIG (with sigmoid activation function) model with performance enhancement of 69.92%, 73.59% and 73.67%, respectively, on the basis of root mean square error as a measure of performance. The four developed models are also compared using correlation coefficient and mean absolute error while the developed GSVR demonstrates a high degree of precision and robustness. The excellent generalization and predictive strength of the developed models would ultimately facilitate quick determination of the band gap of doped graphitic carbon nitride and enhance its visible-light harvesting capacity for various photocatalytic applications.

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