scholarly journals Electrodeposited MnO2-based Capacitive Composite Electrodes for Pb2+ Adsorption

2020 ◽  
Vol 71 (7) ◽  
pp. 284-298
Author(s):  
Tang Chang-Bin ◽  
Niu Hao ◽  
Lu Yu-Xuan ◽  
Wang Fei ◽  
Zhang Yu-Jie ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Nickel Foam ◽  
High Specific Capacitance ◽  
Laser Raman Spectroscopy ◽  
Order Kinetic ◽  
Composite Electrodes ◽  
X Ray ◽  
Laser Raman ◽  
Low Concentrations

In order to effectively realize the removal of low concentrations of lead ions in wastewater via capacitive deionization technology, MnO2 composite electrodes were prepared by a galvanostatic co-deposition approach, where polyaniline (PANI) and graphene were added to an MnO2 deposition solution and nickel foam was chosen as the substrate of the electrode. The microstructure, capacitance characteristics and adsorption behavior of Pb2+ ions of the electrodes were analyzed by scanning electron microscopy, X-ray diffraction, X ray photoelectron spectroscopy, laser Raman spectroscopy, cyclic voltammetry and capacitance deionization processes. The experimental results showed that the MnO2-PANI-graphene composite electrode has a high specific capacitance (132.8 F/g) and a 61.8% removal rate for simulated wastewater containing 20 mg/L Pb2 + ions under the conditions of 30�C and 1 mA/cm2, with the addition of 1 g/L PANI and 3 g/L graphene, respectively. Electroadsorption process was in accordance with the Lagergren quasi-second-order kinetic equation. The co-deposition of PANI and graphene oxide could play obvious role in enhancing the adsorption capacity and stability of the electrodes.

Preparation of Novel Ag–Si–TiO2 Composite and Research on Its Photocatalytic Degradation of Formaldehyde

2021 ◽  
Vol 13 (3) ◽  
pp. 371-380
Author(s):  
Yongjun Wu ◽  
Nina Xie ◽  
Lu Yu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Formaldehyde Concentration ◽  
Order Kinetic ◽  
Solution Ph ◽  
Visible Absorption ◽  
X Ray ◽  
Co Doped

A novel Ag–Si–TiO2 composite was prepared via sol–gel method for removing residual formaldehyde in shiitake mushroom. The structure of Ag–Si–TiO2 composite was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. Ultraviolet-visible absorption spectroscopy (UV-Vis) and N2 adsorption-desorption tests showed that Ag and Si co-doped decreased the band gap, the Brunauer-Emmett-Teller (BET) specific surface area of the samples increased and the recombination probability of electron-hole pairs (e--h+) reduced. Effect on removal rate of formaldehyde with different Ag-Si co-doped content, formaldehyde concentration and solution pH were investigated, and the results showed that 6.0 wt%Ag-3.0 wt%Si-TiO2 samples had an optimum catalytic performance, and the degradation efficiency reached 96.6% after 40 W 365 nm UV lamp irradiation for 360 min. The kinetics of formaldehyde degradation by Ag–Si–TiO2 composite photocatalyst could be described by Langmuir-Hinshelwood first-order kinetic model.

Redox Reactions of Iron and Uranium Dioxide in Simulated Cement Pore Water Under Anoxic Conditions

2002 ◽  
Vol 757 ◽  
Author(s):  
Daqing Cui ◽  
Kastriot Spahiu ◽  
Paul Wersin
Keyword(s):  
Photoelectron Spectroscopy ◽  
Redox Reactions ◽  
Pore Fluid ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Exchange Reactions ◽  
Anoxic Conditions ◽  
X Ray ◽  
Laser Raman ◽  
Corrosion Of Iron

Results on the chemical behavior of Fe(0) and UO2(s), as well as the interaction between fresh and corroded iron with U(VI) in simulated cement contacting alkaline solution are reported. Batch experiments were conducted under anoxic conditions at different alkalinities and salt concentrations to investigate: (a) the corrosion of iron foils (b) the U(VI) removal by fresh, aged and pre-treated (with FeS or Fe3O4 layers) iron surfaces in a simulated cement pore fluid, (c) the dissolution rates of newly reduced UO2.00 slices in simulated cement pore fluid and KOH solutions (pH 12.7) and (d) the isotope exchange reactions between dissolved 235U(VI) and 238UO2(s). The reacted iron and UO2(s) surfaces were analyzed by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectra (SEM-EDS), laser Raman spectroscopy and X-ray photoelectron, spectroscopy (XPS).

An X-ray Photoelectron (ESCA) and Laser Raman Spectroscopic Investigation of Aluminum Perrhenate

1980 ◽  
Vol 34 (6) ◽  
pp. 624-626 ◽  
Author(s):  
Lawrence Salvati ◽  
Gerald L. Jones ◽  
David M. Hercules
Keyword(s):  
Raman Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Heterogeneous Catalysts ◽  
Laser Raman Spectroscopy ◽  
Compound Formation ◽  
Reduction Behavior ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Laser Raman ◽  
Significant Interest

Compound formation in supported heterogeneous catalysts is an area of significant interest. In the present study, Al(ReO4)3 was prepared and characterized by x-ray photoelectron spectroscopy and laser Raman spectroscopy. Characteristic spectra for Al(ReO4)3 are shown and compared to several rhenium reference compounds. The reduction behavior of Al(ReO4)3 is also explored; it was completely reduced to elemental rhenium in H2 at 500°C.

scholarly journals Reduction of NOx by H2 on WOx-Promoted Pt/Al2O3/SiO2 Catalysts Under O2-Rich Conditions

2021 ◽  
Author(s):  
Enno Eßer ◽  
Daniel Schröder ◽  
Anna V. Nartova ◽  
Aleksey M. Dmitrachkov ◽  
Sven Kureti
Keyword(s):  
Photoelectron Spectroscopy ◽  
Laser Raman Spectroscopy ◽  
Promoting Effect ◽  
X Ray ◽  
Laser Raman ◽  
Supported Pt Catalysts ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Temperature Programmed ◽  
Diffuse Reflectance Infrared

AbstractThis work addresses the reduction of NOx by H2 under O2-rich conditions using Al2O3/SiO2-supported Pt catalysts with different loads of WOx promotor. The samples were thoroughly characterised by N2 physisorption, temperature-programmed desorption of CO, scanning electron microscopy, X-ray diffraction, laser raman spectroscopy, X-ray photoelectron spectroscopy and diffuse reflectance infrared fourier transform spectroscopy with probe molecule CO. The catalytic studies of the samples without WOx showed pronounced NOx conversion below 200 °C, whereas highest efficiency was related to small Pt particles. The introduction of WOx provided increasing deNOx activity as well as N2 selectivity. This promoting effect was referred to an additional reaction path at the Pt-WOx/Al2O3/SiO2 interface, whereas an electronic activation of Pt by strong metal support interaction was excluded. Graphic Abstract

scholarly journals Study on Adsorption Properties of Modified Corn Cob Activated Carbon for Mercury Ion

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4483
Author(s):  
Yuyingnan Liu ◽  
Xinrui Xu ◽  
Bin Qu ◽  
Xiaofeng Liu ◽  
Weiming Yi ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Raw Material ◽  
Order Kinetic ◽  
Mercury Ions ◽  
Corn Cob ◽  
Adsorption Time ◽  
X Ray

In this study, corn cob was used as raw material and modified methods employing KOH and KMnO4 were used to prepare activated carbon with high adsorption capacity for mercury ions. Experiments on the effects of different influencing factors on the adsorption of mercury ions were undertaken. The results showed that when modified with KOH, the optimal adsorption time was 120 min, the optimum pH was 4; when modified with KMnO4, the optimal adsorption time was 60 min, the optimal pH was 3, and the optimal amount of adsorbent and the initial concentration were both 0.40 g/L and 100 mg/L under both modified conditions. The adsorption process conforms to the pseudo-second-order kinetic model and Langmuir model. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Zeta potential characterization results showed that the adsorption process is mainly physical adsorption, surface complexation and ion exchange.

scholarly journals Highly Efficient Adsorption of Aqueous Pb(II) with Mesoporous Metal-Organic Framework-5: An Equilibrium and Kinetic Study

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
José María Rivera ◽  
Susana Rincón ◽  
Cherif Ben Youssef ◽  
Alejandro Zepeda
Keyword(s):  
Kinetic Study ◽  
Photoelectron Spectroscopy ◽  
Metal Organic Framework ◽  
Isotherm Models ◽  
Ionic Exchange ◽  
Order Kinetic ◽  
X Ray ◽  
Metal Organic ◽  
Mesoporous Metal ◽  
Organic Framework

Mesoporous metal-organic framework-5 (MOF-5), with the composition Zn4O(BDC)3, showed a high capacity for the adsorptive removal of Pb(II) from 100% aqueous media. After the adsorption process, changes in both morphology and composition were detected using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) system, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis. The experimental evidence showed that Zn(II) liberation from MOF-5 structure was provoked by the water effect demonstrating that Pb(II) removal is not due to ionic exchange with Zn. A kinetic study showed that Pb(II) removal was carried out in 30 min with a behavior of pseudo-second-order kinetic model. The experimental data on Pb(II) adsorption were adequately fit by both the Langmuir and BET isotherm models with maximum adsorption capacities of 658.5 and 412.7 mg/g, respectively, at pH 5 and 45°C. The results of this work demonstrate that the use of MOF-5 has great potential for applications in environmental protection, especially regarding the removal of the lead present in industrial wastewaters and tap waters.

scholarly journals A Novel Synthetic UV-Curable Fluorinated Siloxane Resin for Low Surface Energy Coating

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 979 ◽  
Author(s):  
Chunfang Zhu ◽  
Haitao Yang ◽  
Hongbo Liang ◽  
Zhengyue Wang ◽  
Jun Dong ◽  
...  
Keyword(s):  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Proton Nuclear Magnetic Resonance ◽  
Energy Materials ◽  
Uv Curable ◽  
X Ray ◽  
Low Surface Energy ◽  
Low Concentrations ◽  
Siloxane Polymers

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing.

scholarly journals Effect of Graphene Oxide Concentration in Electrolyte on Corrosion Behavior of Electrodeposited Zn–Electrochemical Reduction Graphene Composite Coatings

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 758 ◽  
Author(s):  
Yang ◽  
Zhang ◽  
Wang ◽  
Wang ◽  
Chen ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Laser Raman Spectroscopy ◽  
304 Stainless Steel ◽  
Sulfate Electrolyte ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tafel Polarization ◽  
Laser Raman

Pure Zn and Zn–ERGO composite coatings were prepared by direct current electrodeposition on 304 stainless steel. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS), and laser Raman spectroscopy (Raman). Results obtained have shown that the concentration of GO sheets in zinc sulfate electrolyte has an important effect on the preferred crystal orientation and the surface morphology of Zn–ERGO composite coatings. A study of the corrosion behavior of the coatings by Tafel polarization and electrochemical impedance spectroscopic (EIS) methods leads to the conclusion that the Zn-1.0 g/L ERGO composite coating possesses the best corrosion resistance compared to the pure Zn coating and other composite coatings in this study.

scholarly journals Preparation of pod-shaped TiO 2 and Ag@TiO 2 nano burst tubes and their photocatalytic activity

2019 ◽  
Vol 6 (9) ◽  
pp. 191019 ◽  
Author(s):  
Shang Wang ◽  
Zhaolian Han ◽  
Tingting Di ◽  
Rui Li ◽  
Siyuan Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Oxalic Acid ◽  
Ultraviolet Light ◽  
Photoelectron Spectroscopy ◽  
Degradation Process ◽  
Catalytic Performance ◽  
Tetrabutyl Titanate ◽  
Order Kinetic ◽  
X Ray

The pod-shaped TiO 2 nano burst tubes (TiO 2 NBTs) were prepared by the combination of electrospinning and impregnation calcination with oxalic acid (H 2 C 2 O 4 ), polystyrene (PS) and tetrabutyl titanate. The silver nanoparticles (AgNPs) were loaded onto the surface of TiO 2 NBTs by ultraviolet light reduction method to prepare pod-shaped Ag@TiO 2 NBTs. In this work, we analysed the effect of the amount of oxalic acid on the cracking degree of TiO 2 NBTs; the effect of the concentration of AgNO 3 solution on the particle size and loading of AgNPs on the surface of TiO 2 NBTs. Scanning electron microscopy and transmission electron microscopy investigated the surface morphology of samples. X-ray diffraction and X-ray photoelectron spectroscopy characterized the structure and composition of samples. Rhodamine B (RhB) solution was used to evaluate the photocatalytic activity of pod-shaped TiO 2 NBTs and Ag@TiO 2 NBTs. The results showed that TiO 2 NBTs degraded 91.0% of RhB under ultraviolet light, Ag@TiO 2 NBTs degraded 95.5% under visible light for 75 and 60 min, respectively. The degradation process of both samples was consistent with the Langmuir–Hinshelwood first-order kinetic equation. Therefore, the catalytic performance of the sample is: Ag@TiO 2 NBTs > TiO 2 NBTs > TiO 2 nanotubes.

scholarly journals Nanosheets of CuCo2O4 As a High-Performance Electrocatalyst in Urea Oxidation

2019 ◽  
Vol 9 (4) ◽  
pp. 793 ◽  
Author(s):  
Camila Zequine ◽  
Fangzhou Wang ◽  
Xianglin Li ◽  
Deepa Guragain ◽  
S.R. Mishra ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Nickel Foam ◽  
Low Cost ◽  
Agricultural Waste ◽  
Bifunctional Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electroactive Material

The urea oxidation reaction (UOR) is a possible solution to solve the world’s energy crisis. Fuel cells have been used in the UOR to generate hydrogen with a lower potential compared to water splitting, decreasing the costs of energy production. Urea is abundantly present in agricultural waste and in industrial and human wastewater. Besides generating hydrogen, this reaction provides a pathway to eliminate urea, which is a hazard in the environment and to people’s health. In this study, nanosheets of CuCo2O4 grown on nickel foam were synthesized as an electrocatalyst for urea oxidation to generate hydrogen as a green fuel. The synthesized electrocatalyst was characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electroactivity of CuCo2O4 towards the oxidation of urea in alkaline solution was evaluated using electrochemical measurements. Nanosheets of CuCo2O4 grown on nickel foam required the potential of 1.36 V in 1 M KOH with 0.33 M urea to deliver a current density of 10 mA/cm2. The CuCo2O4 electrode was electrochemically stable for over 15 h of continuous measurements. The high catalytic activities for the hydrogen evolution reaction make the CuCo2O4 electrode a bifunctional catalyst and a promising electroactive material for hydrogen production. The two-electrode electrolyzer demanded a potential of 1.45 V, which was 260 mV less than that for the urea-free counterpart. Our study suggests that the CuCo2O4 electrode can be a promising material as an efficient UOR catalyst for fuel cells to generate hydrogen at a low cost.

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