scholarly journals Selective Oxofunctionalization of Cyclohexene over Titanium Dioxide-Based and Bismuth Oxyhalide Photocatalysts by Visible Light Irradiation

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1448
Author(s):  
Adolfo Henríquez ◽  
Héctor D. Mansilla ◽  
Azael Martínez-de la Cruz ◽  
Lorena Cornejo-Ponce ◽  
Eduardo Schott ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Molecular Oxygen ◽  
Low Cost ◽  
Ambient Conditions ◽  
Metal Halide Lamp ◽  
Relevant Role ◽  
Bismuth Oxyhalide ◽  
Potential Use ◽  
Oxygenated Products

Photocatalysis driven under visible light allows us to carry out hydrocarbon oxofunctionalization under ambient conditions, using molecular oxygen as a sacrificial reagent, with the absence of hazardous subproducts and the potential use of the Sun as a clean and low-cost source of light. In this work, eight materials—five based on titanium dioxide and three based on bismuth oxyhalides—were used as photocatalysts in the selective oxofunctionalization of cyclohexene. The cyclohexane oxofunctionalization reactions were performed inside of a homemade photoreactor equipped with a 400 W metal halide lamp and injected air as a source of molecular oxygen. In all assayed systems, the main oxygenated products, identified by mass spectrometry, were 1,2-epoxycyclohexane, 2-cyclohexen-1-ol, and 2-cyclohexen-1-one. Titanium dioxide-based materials exhibited higher selectivities for 1,2-epoxycyclohexane than bismuth oxyhalide-based materials. In addition to this, titanium dioxide doped with iron exhibited the best selectivity for 1,2-epoxycyclohexane, demonstrating that iron plays a relevant role in the cyclohexene epoxidation process.

Non-plasmonic metal nanoparticles as visible light photocatalysts for the selective oxidation of aliphatic alcohols with molecular oxygen at near ambient conditions

2016 ◽  
Vol 52 (77) ◽  
pp. 11567-11570 ◽  
Author(s):  
Tana Tana ◽  
Xiao-Wei Guo ◽  
Qi Xiao ◽  
Yiming Huang ◽  
Sarina Sarina ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Metal Nanoparticles ◽  
Molecular Oxygen ◽  
Selective Oxidation ◽  
Aliphatic Alcohols ◽  
Product Selectivity ◽  
Ambient Conditions ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Non-plasmonic Pd NPs and Pt NPs exhibit superior visible light photocatalytic activity and distinctly different product selectivity in the oxidation of aliphatic alcohols.

scholarly journals Bismuth vanadate: A versatile heterogeneous catalyst for photocatalytic functionalization of C(sp2)–H bonds

2021 ◽  
Author(s):  
Fan-Lin Zeng ◽  
Hu-lin Zhu ◽  
Ru-Nan Wang ◽  
Xiao-Ya Yuan ◽  
Kai Sun ◽  
...  
Keyword(s):  
Amino Acid ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
High Efficiency ◽  
Low Cost ◽  
Bismuth Vanadate ◽  
Amino Acid Esters ◽  
Typical Characteristic ◽  
Ambient Conditions ◽  
Acid Esters

Abstract Bismuth vanadate (BiVO4) could be prepared by the hydrothermal kettle method. Herein, the synthesized BiVO4-180 is demonstrated to be a versatile and stable heterogeneous photocatalyst for a series of C(sp2)–H functionalization reactions under visible light irradiation at ambient conditions. A series of functionalized compounds such as tetrahydroquinolines, 3-arylmethyl indoles, α-aryl α-amino acid esters, and sulfurized/selenized/thiocyanated heterocycles were successfully synthesized in good yields (>70 examples, including modification of drugs and peptides). The BiVO4 photocatalyst has the advantages of being recyclable, low-cost, air-tolerant, and high efficiency, which is the typical characteristic of overcoming the shortcomings of homogeneous catalysts.

Copper doped titanium dioxide as a low-cost visible light photocatalyst for water splitting

Solar Energy ◽  
2021 ◽  
Vol 218 ◽  
pp. 150-156
Author(s):  
Vu Thi Quyen ◽  
Kim Jitae ◽  
Pham Thi Huong ◽  
Le Thi Thu Ha ◽  
Dang My Thanh ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Water Splitting ◽  
Low Cost ◽  
Visible Light Photocatalyst ◽  
Doped Titanium Dioxide

Development and production experience of the multilayer curtain-coated linerboard of Ji’an PM No. 3,

TAPPI Journal ◽  
2014 ◽  
Vol 13 (2) ◽  
pp. 17-25
Author(s):  
JUNMING SHU ◽  
ARTHAS YANG ◽  
PEKKA SALMINEN ◽  
HENRI VAITTINEN
Keyword(s):  
Titanium Dioxide ◽  
High Speed ◽  
Food Packaging ◽  
Production Efficiency ◽  
Positive Impact ◽  
Low Cost ◽  
Board Structure ◽  
Flexographic Printing ◽  
Curtain Coating ◽  
Coating Formulations

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.

Optical Properties of Photodynamic Therapy Drugs in Different Environments: The Paradigmatic Case of Temoporfin

2020 ◽  
Author(s):  
busenur Aslanoglu ◽  
Ilya Yakavets ◽  
Vladimir Zorin ◽  
Henri-Pierre Lassalle ◽  
Francesca Ingrosso ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Optical Properties ◽  
Photodynamic Therapy ◽  
Minimally Invasive ◽  
Visible Light ◽  
Cancer Treatment ◽  
Singlet Oxygen ◽  
Tumor Cells ◽  
Molecular Oxygen ◽  
Computational Tools

Computational tools have been used to study the photophysical and photochemical features of photosensitizers in photodynamic therapy (PDT) –a minimally invasive, less aggressive alternative for cancer treatment. PDT is mainly based by the activation of molecular oxygen through the action of a photoexcited sensitizer (photosensitizer). Temoporfin, widely known as mTHPC, is a second-generation photosensitizer, which produces the cytotoxic singlet oxygen when irradiated with visible light and hence destroys tumor cells. However, the bioavailability of the mostly hydrophobic photosensitizer, and hence its incorporation into the cells, is fundamental to achieve the desired effect on malignant tissues by PDT. In this study, we focus on the optical properties of the temoporfin chromophore in different environments –in <i>vacuo</i>, in solution, encapsulated in drug delivery agents, namely cyclodextrin, and interacting with a lipid bilayer.

Solution Processed Sb2S3-based Photocathode with Enhanced Photocatalytic Performance via Constructing Ultrathin TiO2 Overlayer and Noble Metal Modification

2021 ◽  
Author(s):  
Yanwen Wang ◽  
Rong Liang ◽  
Chao Qin ◽  
Lei Ren ◽  
Zhizhen Ye ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
Light Response ◽  
Solution Processed ◽  
Antimony Sulfide ◽  
Visible Light Response ◽  
Absorbing Material

Antimony sulfide (Sb2S3) is a light absorbing material with strong visible light response, which is suitable for efficient and low-cost photoelectrodes. Nano-structured films have unique advantages in constructing photoelectrodes due...

Visible-light-initiated Catalyst-free Oxidative Cleavage of Triaryl-Substituted Alkenes C=C Bonds under Ambient Conditions

2021 ◽  
Author(s):  
Wenjing Li ◽  
Shun Li ◽  
Lihua Luo ◽  
Yichen Ge ◽  
Jiaqi Xu ◽  
...  
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Ambient Air ◽  
Oxidative Cleavage ◽  
Ambient Conditions ◽  
Blue Led ◽  
Catalyst Free

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing pyridyl motif with ambient air under irradiation of blue LED at room temperature has been developed. The reaction was facile and scalable,...

scholarly journals Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Mayra K. S. Monteiro ◽  
Djalma R. Da Silva ◽  
Marco A. Quiroz ◽  
Vítor J. P. Vilar ◽  
Carlos A. Martínez-Huitle ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Linear Response ◽  
High Performance ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Caffeine Concentration ◽  
Real Samples ◽  
Wide Range ◽  
Potential Use

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5–1000 µM), with R2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.

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