Protonation Degree of Doped Polyaniline with Sulfosalicylic Acid as Function of the Synthetic Method

2010 ◽  
Vol 663-665 ◽  
pp. 462-465 ◽  
Author(s):  
Hui Huang ◽  
Zhong Cheng Guo ◽  
Ju Kang Li ◽  
Bu Ming Chen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Dispersion Polymerization ◽  
Aqueous Dispersion ◽  
Synthetic Methods ◽  
Substantial Portion ◽  
Sulfosalicylic Acid ◽  
X Ray ◽  
Molar Ratios ◽  
Doped Polyaniline ◽  
Protonation Degree

X-ray photoelectron spectroscopy (XPS) has been employed to investigate the protonation degree of polyaniline doped with sulfosalicylic acid (PAni-SSA) obtained by different synthetic methods. The protonation degree has been compared to electrical conductivity. Prepared PAni-SSA through the redoping process in an agate mortar displays conductivity values within the range of 1S/cm. Protonation degree of synthesized PAni-SSA by aqueous dispersion polymerization of aniline in the presence of SSA is higher than 50 %, indicating that a substantial portion of amine units have also been protonated. The C/N and S/N molar ratios obtained by XPS analysis indicate that the polyaniline chains obtained by aqueous dispersion polymerization are protonated by both sulfate anions.

scholarly journals Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Oxidation Potential ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Optimum Parameters ◽  
Reduction Of Co2 ◽  
Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

scholarly journals Silica-Copper Oxide Composite Thin Films as Solar Selective Coatings Prepared by Dipping Sol Gel

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
E. Barrera-Calva ◽  
J. Méndez-Vivar ◽  
M. Ortega-López ◽  
L. Huerta-Arcos ◽  
J. Morales-Corona ◽  
...  
Keyword(s):  
Thin Films ◽  
Stainless Steel ◽  
Copper Oxide ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Silica Matrix ◽  
Composite Thin Films ◽  
X Ray ◽  
Molar Ratios ◽  
Steel Substrates

Silica-copper oxide (silica-CuO) composite thin films were prepared by a dipping sol-gel route using ethanolic solutions comprised TEOS and a copper-propionate complex. Sols with different TEOS/Cu-propionate (Si/Cu) molar ratios were prepared and applied on stainless steel substrates using dipping process. During the annealing process, copper-propionate complexes developed into particulate polycrystalline CuO dispersed in a partially crystallized silica matrix, as indicated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. The gel thermal analysis revealed that the prepared material might be stable up to400°C. The silica-CuO/stainless steel system was characterized as a selective absorber surface and its solar selectivity parameters, absorptance (α), and emittance (ε) were evaluated from UV-NIR reflectance data. The solar parameters of such a system were mostly affected by the thickness and phase composition of theSiO2-CuO film. Interestingly, the best solar parameters (α= 0.92 andε= 0.2) were associated to the thinnest films, which comprised a CuO-Cu2Omixture immersed in the silica matrix, as indicated by XPS.

scholarly journals Optimization of sol-immobilized bimetallic Au–Pd/TiO 2 catalysts: reduction of 4-nitrophenol to 4-aminophenol for wastewater remediation

2020 ◽  
Vol 378 (2176) ◽  
pp. 20200057
Author(s):  
Khaled Alshammari ◽  
Yubiao Niu ◽  
Richard E. Palmer ◽  
Nikolaos Dimitratos
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
Wastewater Remediation ◽  
X Ray ◽  
Molar Ratios ◽  
Highly Active ◽  
Transmission Electron ◽  
Complementary Techniques

A sol-immobilization method is used to synthesize a series of highly active and stable Au x Pd 1− x /TiO 2 catalysts (where x  = 0, 0.13, 0.25, 0.5, 0.75, 0.87 and 1) for wastewater remediation. The catalytic performance of the materials was evaluated for the catalytic reduction of 4-nitrophenol, a model wastewater contaminant, using NaBH 4 as the reducing agent under mild reaction conditions. Reaction parameters such as substrate/metal and substrate/reducing agent molar ratios, reaction temperature and stirring rate were investigated. Structure-activity correlations were studied using a number of complementary techniques including X-ray powder diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The sol-immobilization route provides very small Au–Pd alloyed nanoparticles, with the highest catalytic performance shown by the Au 0.5 Pd 0.5 /TiO 2 catalyst. This article is part of a discussion meeting issue ‘Science to enable the circular economy’.

scholarly journals Structural, Surface Morphology and Optical Properties of ZnS Films by Chemical Bath Deposition at Various Zn/S Molar Ratios

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Fei-Peng Yu ◽  
Sin-Liang Ou ◽  
Pin-Chuan Yao ◽  
Bing-Rui Wu ◽  
Dong-Sing Wuu
Keyword(s):  
Chemical Bath Deposition ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Film Surface ◽  
Optical Transmittance ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
X Ray ◽  
Molar Ratios ◽  
Zns Films

In this study, ZnS thin films were prepared on glass substrates by chemical bath deposition at various Zn/S molar ratios from 1/50 to 1/150. The effects of Zn/S molar ratio in precursor on the characteristics of ZnS films were demonstrated by X-ray diffraction, scanning electron microscopy, optical transmittance, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry. It was found that more voids were formed in the ZnS film prepared using the precursor with Zn/S molar ratio of 1/50, and the other ZnS films showed the denser structure as the molar ratio was decreased from 1/75 to 1/150. From the analyses of chemical bonding states, the ZnS phase was indeed formed in these films. Moreover, the ZnO and Zn(OH)2also appeared due to the water absorption on film surface during deposition. This would be helpful to the junction in cell device. With changing the Zn/S molar ratio from 1/75 to 1/150, the ZnS films demonstrate high transmittance of 75–88% in the visible region, indicating the films are potentially useful in photovoltaic applications.

Synthesis and Properties of Conducting Polyaniline by Co-Doping with Sulfosalicylic Acid and Sulfate Acid

2010 ◽  
Vol 663-665 ◽  
pp. 481-485 ◽  
Author(s):  
Hui Huang ◽  
Zhong Cheng Guo ◽  
Ju Kang Li
Keyword(s):  
Fourier Transform ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Chemical Oxidative Polymerization ◽  
Sulfosalicylic Acid ◽  
X Ray ◽  
Co Doping ◽  
Doped Polyaniline ◽  
Fourier Transform Raman ◽  
Ft Raman

A chemical oxidative polymerization of aniline sulfosalicylic acid (ANISSA) and aniline sulfate acid (ANIH2SO4) was performed in an aqueous solution. A co-doped polyaniline (PANI) was thus obtained, a higher conductivity than the insoluble H2SO4-doped PANI compressed pellet, and much higher conductivity than that prepared from pure ANISSA. The PANI doped with SSA and H2SO4 was characterized using Fourier-transform infrared spectra (FTIR), Fourier-transform Raman spectra (FT-Raman), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The investigation reveals that SSA and H2SO4 as dopant not only enhances crystallinity of polyaniline but also stability of polyaniline.

scholarly journals High Active PdSn Binary Alloyed Catalysts Supported on B and N Codoped Graphene for Formic Acid Electro-Oxidation

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Dan Chen ◽  
Shien Pei ◽  
Zhishun He ◽  
Haibo Shao ◽  
Jianming Wang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Photoelectron Spectroscopy ◽  
Metallic Nanoparticles ◽  
Moderate Amount ◽  
X Ray ◽  
Sn Doping ◽  
Electrochemical Tests ◽  
Molar Ratios ◽  
Co Doping ◽  
Electro Oxidation

A series of PdSn binary catalysts with varied molar ratios of Pd to Sn are synthesized on B and N dual-doped graphene supporting materials. The catalysts are characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Formic acid electro-oxidation reaction is performed on these catalysts, and the results reveal that the optimal proportion of Pd:Sn is 3:1. X-ray photoelectron spectroscopy (XPS) measurements show that when compared with 3Pd1Sn/graphene, B and N co-doping into the graphene sheet can tune the electronic structure of graphene, favoring the formation of small-sized metallic nanoparticles with good dispersion. On the other hand, when compared with the monometallic counterparts, the incorporation of Sn can generate oxygenated species that help to remove the intermediates, exposing more active Pd sites. Moreover, the electrochemical tests illustrate that 3Pd1Sn/BN-G catalyst with a moderate amount of Sn exhibits the best catalytic activity and stability on formic acid electro-oxidation, owing to the synergistic effect of the Sn doping and the B, N co-doping graphene substrate.

scholarly journals Photocatalytic and Oxidative Synthetic Pathways for Highly Efficient PANI-TiO2 Nanocomposites as Organic and Inorganic Pollutant Sorbents

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 441 ◽  
Author(s):  
Carolina Cionti ◽  
Cristina Della Pina ◽  
Daniela Meroni ◽  
Ermelinda Falletta ◽  
Silvia Ardizzone
Keyword(s):  
Reaction Mechanism ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Pollutant Removal ◽  
Full Potential ◽  
X Ray ◽  
Molar Ratios ◽  
Inorganic Pollutant ◽  
Dye Sorption ◽  
Maximum Sorption

Polyaniline (PANI)-materials have recently been proposed for environmental remediation applications thanks to PANI stability and sorption properties. As an alternative to conventional PANI oxidative syntheses, which involve toxic carcinogenic compounds, an eco-friendly procedure was here adopted starting from benign reactants (aniline-dimer and H2O2) and initiated by ultraviolet (UV)-irradiated TiO2. To unlock the full potential of this procedure, we investigated the roles of TiO2 and H2O2 in the nanocomposites synthesis, with the aim of tailoring the properties of the final material to the desired application. The nanocomposites prepared by varying the TiO2:H2O2:aniline-dimer molar ratios were characterized for their thermal, optical, morphological, structural and surface properties. The reaction mechanism was investigated via mass analyses and X-ray photoelectron spectroscopy. The nanocomposites were tested on both methyl orange and hexavalent chromium removal. A fast dye-sorption was achieved also in the presence of interferents and the recovery of the dye was obtained upon eco-friendly conditions. An efficient Cr(VI) abatement was obtained also after consecutive tests and without any regeneration treatment. The fine understanding of the reaction mechanism allowed us to interpret the pollutant-removal performances of the different materials, leading to tailored nanocomposites in terms of maximum sorption and reduction capability upon consecutive tests even in simulated drinking water.

scholarly journals ORR in Non-Aqueous Solvent for Li-Air Batteries: The Influence of Doped MnO2-Nanoelectrocatalyst

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1735 ◽  
Author(s):  
Eleonora Pargoletti ◽  
Annalisa Salvi ◽  
Alessia Giordana ◽  
Giuseppina Cerrato ◽  
Mariangela Longhi ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Reduction Reaction ◽  
Negative Consequences ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Fe Content ◽  
Aqueous Solvent ◽  
Lithium Air Batteries ◽  
Kinetics Of

One of the major drawbacks in Lithium-air batteries is the sluggish kinetics of the oxygen reduction reaction (ORR). In this context, better performances can be achieved by adopting a suitable electrocatalyst, such as MnO2. Herein, we tried to design nano-MnO2 tuning the final ORR electroactivity by tailoring the doping agent (Co or Fe) and its content (2% or 5% molar ratios). Staircase-linear sweep voltammetries (S-LSV) were performed to investigate the nanopowders electrocatalytic behavior in organic solvent (propylene carbonate, PC and 0.15 M LiNO3 as electrolyte). Two percent Co-doped MnO2 revealed to be the best-performing sample in terms of ORR onset shift (of ~130 mV with respect to bare glassy carbon electrode), due to its great lattice defectivity and presence of the highly electroactive γ polymorph (by X-ray diffraction analyses, XRPD and infrared spectroscopy, FTIR). 5% Co together with 2% Fe could also be promising, since they exhibited fewer diffusive limitations, mainly due to their peculiar pore distribution (by Brunauer–Emmett-Teller, BET) that disfavored the cathode clogging. Particularly, a too-high Fe content led to iron segregation (by energy dispersive X-ray spectroscopy, EDX, X-ray photoelectron spectroscopy, XPS and FTIR) provoking a decrease of the electroactive sites, with negative consequences for the ORR.

scholarly journals Zn-Al Mixed Oxides Decorated with Potassium as Catalysts for HT-WGS: Preparation and Properties

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1094 ◽  
Author(s):  
Katarzyna Antoniak-Jurak ◽  
Paweł Kowalik ◽  
Kamila Michalska ◽  
Wiesław Próchniak ◽  
Robert Bicki
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Catalyst Activity ◽  
Molar Ratio ◽  
X Ray ◽  
Molar Ratios ◽  
Mixed Oxide Catalysts ◽  
Wgs Reaction ◽  
Temperature Programmed ◽  
Co Precipitation

A set of ex-ZnAl-LDHs catalysts with a molar ratio of Zn/Al in the range of 0.3–1.0 was prepared using co-precipitation and thermal treatment. The samples were characterized using various methods, including X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy FT-IR, N2 adsorption, Temperature-programmed desorption of CO2 (TPD-CO2) as well as Scanning electron microscopy (SEM-EDS). Catalyst activity and long-term stability measurements were carried out in a high-temperature water–gas shift (HT-WGS) reaction. Mixed oxide catalysts with various Zn/Al molar ratios decorated with potassium showed high activity in the HT-WGS reaction within the temperature range of 330–400 °C. The highest activity was found for the Zn/Al molar ratio of 0.5 corresponding to spinel stoichiometry. However, the catalyst with a stoichiometric spinel molar ratio of Zn/Al (ZnAl_0.5_K) revealed a higher tendency for surface migration and/or vaporization of potassium during overheating at 450 °C. The correlation of the activity results and TPD-CO2 data show that medium basic sites enhance the progress of the HT-WGS reaction.

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