scholarly journals Wet-Chemically Prepared Porphyrin Layers on Rutile TiO2(110)

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2871
Author(s):  
Daniel Wechsler ◽  
Cynthia Carolina Fernández ◽  
Julia Köbl ◽  
Lisa-Marie Augustin ◽  
Corinna Stumm ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Deposition ◽  
Ultrahigh Vacuum ◽  
Zinc Ion ◽  
Ambient Conditions ◽  
Rutile Tio2 ◽  
Single Crystal Surfaces ◽  
Wet Chemical

Porphyrins are large organic molecules that are interesting for different applications, such as photovoltaic cells, gas sensors, or in catalysis. For many of these applications, the interactions between adsorbed molecules and surfaces play a crucial role. Studies of porphyrins on surfaces typically fall into one of two groups: (1) evaporation onto well-defined single-crystal surfaces under well-controlled ultrahigh vacuum conditions or (2) more application-oriented wet chemical deposition onto less well-defined high surface area surfaces under ambient conditions. In this study, we will investigate the wet chemical deposition of 5-(monocarboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP) on well-defined rutile TiO2(110) single crystals under ambient conditions. Prior to deposition, the TiO2(110) crystals were also cleaned wet-chemically under ambient conditions, meaning none of the preparation steps were done in ultrahigh vacuum. However, after each preparation step, the surfaces were characterized in ultrahigh vacuum with X-ray photoelectron spectroscopy (XPS) and the result was compared with porphyrin layers prepared in ultrahigh vacuum (UHV) by evaporation. The differences of both preparations when exposed to zinc ion solutions will also be discussed.

scholarly journals Non-Thermal Plasma-Modified Ru-Sn-Ti Catalyst for Chlorinated Volatile Organic Compound Degradation

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1456
Author(s):  
Yujie Fu ◽  
You Zhang ◽  
Qi Xin ◽  
Zhong Zheng ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Surface Oxidation ◽  
Treatment Method ◽  
X Ray ◽  
Chlorinated Volatile Organic Compounds ◽  
Volatile Organic ◽  
Doped Titania

Chlorinated volatile organic compounds (CVOCs) are vital environmental concerns due to their low biodegradability and long-term persistence. Catalytic combustion technology is one of the more commonly used technologies for the treatment of CVOCs. Catalysts with high low-temperature activity, superior selectivity of non-toxic products, and resistance to chlorine poisoning are desirable. Here we adopted a plasma treatment method to synthesize a tin-doped titania loaded with ruthenium dioxide (RuO2) catalyst, possessing enhanced activity (T90%, the temperature at which 90% of dichloromethane (DCM) is decomposed, is 262 °C) compared to the catalyst prepared by the conventional calcination method. As revealed by transmission electron microscopy, X-ray diffraction, N2 adsorption, X-ray photoelectron spectroscopy, and hydrogen temperature-programmed reduction, the high surface area of the tin-doped titania catalyst and the enhanced dispersion and surface oxidation of RuO2 induced by plasma treatment were found to be the main factors determining excellent catalytic activities.

scholarly journals Preparation and Characterization of Biocompatible Electrospun Nanofiber Scaffolds

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Edit Hirsch ◽  
Márió Nacsa ◽  
Ferenc Ender ◽  
Miklós Mohai ◽  
Zsombor K. Nagy ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Surface Characteristic ◽  
Poly Lactic Acid ◽  
Nanofibrous Scaffolds ◽  
Plasma Surface Treatment ◽  
Nanoscale Fibers ◽  
Solution Electrospinning

Nanoscale fibers were prepared for the fabrication of scaffolds by using a strong electrostatic field on the polymer solution. Electrospinning is widely applied for production of drug delivery, tissue engineering, and regenerative medicine systems as well as biosensors and enzyme immobilization. Nanofibers, thanks to their high surface area to volume ratio, can also mimic the extracellular matrix, thus it has been recognized as a suitable technique for the fast fabrication of scaffolds. This article demonstrates the fabrication of several nanofibrous scaffolds from biopolymers such as polycaprolactone, poly(lactic acid), poly(lactide-co-glycolide), poly(lactide-co-caprolactone) and poly(hydroxybutyrate-co-hydroxy valerate). The characterization and comparison of the scaffolds were achieved based on the morphology and surface characteristic of the nanofibers. The samples showed hydrophobic characteristic, thus a plasma surface treatment was applied successfully to increase hydrophilicity and the effect of the treatment was evaluated based on the wettability and the change in elemental composition of the surface based on X-ray photoelectron spectroscopy.

Fabrication of Energy Materials by a Functional Electrochemical Mold

2018 ◽  
Vol 939 ◽  
pp. 120-126
Author(s):  
Chien Wan Hun ◽  
Chien Wen Yeh ◽  
Shao Fu Chang ◽  
Wern Dare Jheng ◽  
Chih Yuan Chen ◽  
...  
Keyword(s):  
Current Density ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Deposition ◽  
Small Sample ◽  
Energy Materials ◽  
Experimental Conditions ◽  
Electro Deposition ◽  
Group Water

The energy materials such as titania (TiO2) and alumina (Al2O3) are the environmental friendly materials. In this paper the nanostructure of high surface area titania and alumina are fabricated by anodization process and assistance in electrochemical mold. In general, academic or research institutes can simply control the required experimental conditions in a small sample; however, it’s difficult to control the stable parameters in a large surface and a large number of nanostructural products in the industry production. In order to solve the problems of unstable current density and temperature we have designed a cooling functional electrochemical mold which can improve the nanostructural quality of energy materials during a large number production. The electrochemical mold is used for a local surface treatment at an isothermal temperature controlling. The mold limits sample for a specific treated area and current density in the electrolyte. The mold can be used for the assistance of electrolysis, electro-polishing, electro-deposition, anodization, etching, chemical deposition, pickling, and caustic processes. The mold structure includes fixture group, water-cooling electrode group, and electrode conductive group.

scholarly journals Boron Nitride as a Novel Support for Highly Stable Palladium Nanocatalysts by Atomic Layer Deposition

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 849 ◽  
Author(s):  
Matthieu Weber ◽  
Cassandre Lamboux ◽  
Bruno Navarra ◽  
Philippe Miele ◽  
Sandrine Zanna ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Layer ◽  
Average Diameter ◽  
Transmission Electron Microscopy Analysis ◽  
Layer Deposition ◽  
Palladium Nanocatalysts

The ability to prepare controllable nanocatalysts is of great interest for many chemical industries. Atomic layer deposition (ALD) is a vapor phase technique enabling the synthesis of conformal thin films and nanoparticles (NPs) on high surface area supports and has become an attractive new route to tailor supported metallic NPs. Virtually all the studies reported, focused on Pd NPs deposited on carbon and oxide surfaces. It is, however, important to focus on emerging catalyst supports such as boron nitride materials, which apart from possessing high thermal and chemical stability, also hold great promises for nanocatalysis applications. Herein, the synthesis of Pd NPs on boron nitride (BN) film substrates is demonstrated entirely by ALD for the first time. X-ray photoelectron spectroscopy indicated that stoichiometric BN formed as the main phase, with a small amount of BNxOy, and that the Pd particles synthesized were metallic. Using extensive transmission electron microscopy analysis, we study the evolution of the highly dispersed NPs as a function of the number of ALD cycles, and the thermal stability of the ALD-prepared Pd/BN catalysts up to 750 °C. The growth and coalescence mechanisms observed are discussed and compared with Pd NPs grown on other surfaces. The results show that the nanostructures of the BN/Pd NPs were relatively stable up to 500 °C. Consequent merging has been observed when annealing the samples at 750 °C, as the NPs’ average diameter increased from 8.3 ± 1.2 nm to 31 ± 4 nm. The results presented open up exciting new opportunities in the field of catalysis.

scholarly journals Enhanced Photocatalytic Activity of Titania by Co-Doping with Mo and W

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 631 ◽  
Author(s):  
Osmín Avilés-García ◽  
Jaime Espino-Valencia ◽  
Rubí Romero-Romero ◽  
José Rico-Cerda ◽  
Manuel Arroyo-Albiter ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Absorption Capacity ◽  
Radiation Absorption ◽  
Experimental Conditions ◽  
X Ray ◽  
Assembly Method ◽  
Co Doped

Various W and Mo co-doped titanium dioxide (TiO2) materials were obtained through the EISA (Evaporation-Induced Self-Assembly) method and then tested as photocatalysts in the degradation of 4-chlorophenol. The synthesized materials were characterized by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy (RS), N2 physisorption, UV-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results showed that the W-Mo-TiO2 catalysts have a high surface area of about 191 m2/g, and the presence of an anatase crystalline phase. The co-doped materials exhibited smaller crystallite sizes than those with one dopant, since the crystallinity is inhibited by the presence of both species. In addition, tungsten and molybdenum dopants are distributed and are incorporated into the anatase structure of TiO2, due to changes in red parameters and lattice expansion. Under our experimental conditions, the co-doped TiO2 catalyst presented 46% more 4-chlorophenol degradation than Degussa P25. The incorporation of two dopant cations in titania improved its photocatalytic performance, which was attributed to a cooperative effect by decreasing the recombination of photogenerated charges, high radiation absorption capacity, high surface areas, and low crystallinity. When TiO2 is co-doped with the same amount of both cations (1 wt.%), the highest degradation and mineralization (97% and 74%, respectively) is achieved. Quinones were the main intermediates in the 4-chlorophenol oxidation by W-Mo-TiO2 and 1,2,4-benzenetriol was incompletely degraded.

Hydrothermal Synthesis and Characterization of Phosphor Doped Tetragonal Zirconia Nanocrystallites

2011 ◽  
Vol 197-198 ◽  
pp. 846-852
Author(s):  
Jian Jun Yin ◽  
Tao Wang ◽  
Wei Jing Xing
Keyword(s):  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
High Surface ◽  
High Surface Area ◽  
Tetragonal Zirconia ◽  
Zirconium Oxychloride ◽  
Dihydrogen Phosphate ◽  
Hydrothermal Conditions ◽  
Hydrothermal Temperature ◽  
X Ray

Using zirconium oxychloride hydrate ( ZrOCl2•8H2O) and ammonia water (NH3•H2O) as raw materials, and ammonium dihydrogen phosphate (NH4H2PO4) as additives, tetragonal zirconia (t-ZrO2) with size range of 8–12 nm were prepared by coprecipitation method under hydrothermal conditions. The influence factors on phase transformation and the particle size such as phosphor loading, hydrothermal temperature and calcination temperature were studied by X-ray diffraction (XRD), Fourier transform Roman spectra (FT-Roman), the Brunauer-Emmett-Teller (BET) method and X-ray photoelectron spectroscopy (XPS) techniques etc. Research results show that a small amount of phosphor has been incorporated into the framework of ZrO2 crystals, producing a certain amount of oxygen vacancies. Phosphor can effectively restrain crystal particles growth and improve the thermal stability of metastable t-ZrO2. The phosphor doped t-ZrO2 had a high surface area (244.2 m2/g). In contrast to the pure ZrO2 particles readily aggregating, the phosphor species deposited on the framework of ZrO2 crystals prevented the agglomeration of the primary particles during calcinations.

Synthesis and capacitive properties of carbonaceous sphere@MnO2 rattle-type hollow structures

2010 ◽  
Vol 25 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Jintao Zhang ◽  
Jizhen Ma ◽  
Jianwen Jiang ◽  
X.S. Zhao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Experimental Conditions ◽  
X Ray ◽  
Hollow Structures ◽  
Capacitive Properties

Carbonaceous sphere@MnO2 rattle-type hollow spheres were synthesized under mild experimental conditions. The as-prepared hollow structures were characterized using scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and nitrogen adsorption techniques. The characterization data showed the formation of rattle-type hollow structures with a mesoporous MnO2 shell and a carbonaceous sphere core. The composition and shell thickness of the hollow spheres can be controlled experimentally. The capacitive performance of the hollow structures was evaluated by using both cycle voltammetry and charge–discharge methods. The results demonstrated a specific capacitance as high as 184 F/g at a current density of 125 mA/g. The good electrocapacitive performance resulted from the mesoporous structure and high surface area of the MnO2-based hollow spheres.

scholarly journals Activated carbons for the removal of heavy metal ions: A systematic review of recent literature focused on lead and arsenic ions

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Eleni A. Deliyanni ◽  
George Z. Kyzas ◽  
Kostas S. Triantafyllidis ◽  
Kostas A. Matis
Keyword(s):  
Systematic Review ◽  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Activated Carbons ◽  
Thermal Analyses ◽  
High Surface ◽  
High Surface Area ◽  
Adsorption Removal ◽  
Bet Analysis ◽  
Removal Of Heavy Metals

AbstractThis work is a systematic review of the literature over the past decade of the application of activated carbon (microporous or mesoporous) as adsorbents for the removal of heavy metals, focusing especially on lead (Pb) and arsenic (As) ions from the aqueous phase. Classical examples from our lab are also given. Activated carbon is known to provide a high surface area for adsorption. Generally, surface modification is typically required, such as oxidation, treatment with ammonia or even impregnation with ferric ion, etc. and the adsorbent material may originate from various sources. The pristine materials, after modification and those after batch-wise adsorption, were characterized by available techniques (BET analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, thermal analyses, X-ray photoelectron spectroscopy). Adsorption isotherms, thermodynamics and kinetics of the process are also discussed. Selected studies from the literature are examined in comparison with other adsorbents. The role of chemistry in the metals adsorption/removal was investigated.

scholarly journals Mesoporous CdO/Al2O3 nanocomposite with enhanced optoelectronic properties for visible-light photocatalysis and bactericidal applications

2021 ◽  
Author(s):  
Janani B ◽  
Asad Syed ◽  
Abdallah M. Elgorban ◽  
Ali H. Bahkali ◽  
S. Sudheer Khan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Organic Contaminants ◽  
Dye Degradation ◽  
High Surface ◽  
High Surface Area ◽  
Energy Shift ◽  
Band Gap Energy ◽  
Oh Radicals ◽  
X Ray ◽  
Viable Solution

Abstract Pristine Al2O3 and CdO are known to possess poor photocatalytic activity individually. The formation of CdO/Al2O3 heterojunction was investigated for the enhancement of photocatalytic performance. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) has been used to determine the crystalline feature and elemental composition of the NCs respectively. Peaks ascribed to Cd-O and O-Al-O was noted in fourier-transform infrared spectroscopy (FTIR) analysis. The NCs exhibits a high surface area (27.23 m2/g) to their contributing particles which was analysed using BET analyser. The band gap energy of CdO/Al2O3NCs was observed to be 2.95 eV which shows a considerable energy shift from its individual particles, CdO (2.73 eV) and Al2O3 (3.94 eV). The results displayed that the degradation efficiency of the CdO-Al2O3 NCs was enhanced 14 times than pristine Al2O3 and 3.5 times than pristine CdO. The MB dye has showed the half life period of 80 min. TOC analysis of degraded product supported high mineralization of the pollutants. The dye degradation was driven by OH. radicals and the CdO-Al2O3 nanocomposite possessed high reusability which was confirmed by six cycle test. Growth inhibition of E. coli, P. aeruginosa and B. subtilis was attained by exposure to CdO/Al2O3 NCs. The CdO-Al2O3 NCs can be a viable solution for degradation of organic contaminants effectively under natural sun light as well as an efficient antibacterial agent.

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