bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanostructured Zinc Electrodeposited from Protic Ionic Liquids: Comparison with Zinc Aqueous Electrodeposition Processes
Authors: Ortega R. , Brisard Gessie , Rivas Esquivel Flor 
Published: February 2020

Zinc electrodepositon is one of the more important electrochemical process for surface treatment because of its application in anticorrosion protection and also as electrode material in zinc batteries. The main limitation of the electrodepositon of zinc from acidic or basic solutions in aqueous media, in addition to the very negative potential needed to carry out the electrodeposition, is associated to the simultaneous hydrogen evolucion reaction (HER) limiting the farad¡c efficiency of the electrochemical process. The HER has also a direct effect on the nucleation and on the electrocrystallization of zinc with some negative effects on the physical and structural proporties of zinc electrodeposits obtained from these solution (e.g. (poor adhesion, inhomogeneous deposits, etc).
In this work the electrodeposition processes of zinc from protic ionic liquids is studied and compared with results of electrodeposition from aqueous solution in order to determine the avantages of electrodeposition from ionic liquids.
Results show that in protic carboxylated ionic liquids, as ethanolammonium propionate, homogeneous electrodeposits of pure metallic zinc are obtained, with a narrow distribution of grain size in the range of 50-70nm, contrariously to electrodeposits obtained from aqueos solutions with grain sizes from 20 to 100nm.
In addition, differences in the nucleation-electrocrystallization mechanism and on the electrodeposition rate are observed and they are dependent on the nature of the nature of the solvent.
Results allow to conclude that zinc electrodeposits continous, homogeneous and with a well controlled grain sizes can be obtained from protic ionic liquids. These results allow to envisage that these deposits can be more effective for anticorrosion protection since this property is dependent on the homogeneity and contoinuity of an electrodeposit.
ACKNOWLEDGEMENTS. The financial support provided by CONACYT (México), project Fondo Sectorial SEP-CONACYT CB 2011 168032 and The Engineering Research Council of Canada (NSERC) are gratefully acknowledged.
Study of Aminosilane-Compound Modification Condition on Polished Silicon Wafer and Its Influence on the Adhesion of Electroless Nickel/Phosphorous Film
Authors: Wang Wei-Yan , Hsu Chin Wei , Wei Tzu Chien , Chen Chih-Ming , Lai Kuei-Chang 
Published: February 2020

Electroless deposition (ELD) of nickel/phosphorous (Ni/P) layer has been a special interest in modern technique, especially in the production of diffusion barriers in the silicon industry [1]. The crucial part of ELD is a catalytic reaction that needs a trace amount of palladium [2] as the activator to lower the activation energy of metal formation. Due to the adhesion of ELD Ni/P film is associated with the interfacial property of catalyst and silicon surface. In order to increase the bridging between the silicon substrate and palladium catalyst, modifying silicon surface with organo-silane compound such as 3-[2-(2-aminoethylamino)ethylamino] propyl-trimethoxysilane (ETAS). The ETAS then form a self-assembled monolayer (SAM) to facilitate the adsorption of palladium catalyst [3]. However, it is known that the SAM formation is very sensitive to process condition such as soaking time, soaking temperature and solvent agents. In this study, the ETAS modification condition on silicon wafer is investigated. In particular, the ETAS-modified film was fabricated by a wet-soaking method and the effects of soaking time, soaking temperature and solvent agents onto silicon surface were discussed. As shown in Fig 1, the images of AFM with various soaking time of ETAS-modified silicon surface showed significant difference; this means that the long soaking time did influence SAM formation. Finally, the adhesion of ELD Ni/P on ETAS-modified silicon surface with different process parameters is discussed.

REFERENCES

[1] A. Brenner, G.E. Riddell, J. Res. Nat'l Bur. Std. 37 (1946) 31.
[2] L. Li, B. Liu, Mater. Chem. Phys. 128 (2011) 303.
[3] T. C. Wei, T. P. Pan, C. M. Chen, K. C. Lai, C. H. Wu, Electrochem. Commun. 54 (2015) 6

Figure 1
(Invited) Applications of Solid Electrolyte Membranes in Heterogeneous Catalysis. Electrochemical Reaction and Separation
Authors: Stoukides Michael , Vourros Anastasios , Vasileiou Eirini , Kyriakou Vasileios , Garagounis Ioannis 
Published: February 2020

In addition to their applications in sensors, separators and solid oxide fuel cells, solid electrolytes have been used in the construction of solid state cell-reactors, in which catalytic reactions were studied. Depending on the reaction system, there was a variety of goals in these studies: a) to take advantage of the selective conduction of ions, b) improve the yield to the desired product and c) cogenerate electricity and value-added chemicals. Two examples of applications of solid state cell-reactors in heterogeneous catalysis are presented here, a) the production of ethylene and hydrogen from methane with simultaneous separation of hydrogen from the reaction mixture and b) the electrochemical synthesis of NH3.
The production of hydrogen with simultaneous conversion of methane to C2 hydrocarbons was studied in a solid state oxygen ion (O2-) conducting cell at temperatures between 700 oC and 850 oC. Methane, diluted in nitrogen was introduced over the anode (Ag) and steam, also diluted in nitrogen, was introduced over the cathode (Pt). When oxygen was electrochemically “pumped” from the cathode to the anode, steam was electrolyzed to produce gaseous H2 while CH4 was converted to C2H6, C2H4 and CO2. At the anode, C2yields exceeding 8% were obtained while an up to 65% conversion of steam was achieved at the cathode.
The electrochemical synthesis of ammonia was studied in a proton conducting solid electrolyte cell. The BaZr0.7Ce0.2Y0.1O2.9 (BZCY72) proton conducting ceramic was used as the electrolyte with a Ni-BZCY72 cermet and a Pt film serving as cathodic and anodic electrodes, respectively. The reaction was studied at atmospheric pressure and at temperatures between 450 oC and 700 oC, under both, open- and closed-circuit conditions. A peculiar reaction rate enhancement was observed when the cell returned to open-circuit after operating under closed-circuit for a certain time. A possible explanation of this new phenomenon is that a fraction of protons electrochemically transported to the cathode, is "stored" in the Ni-BZCY72 electrode in the form of a highly reactive hydride which, upon current interruption, reacts with adsorbed N species to produce ammonia.
Water Purification in Porous Media Via Shock Electrodialysis
Authors: Schlumpberger Sven , Lu Nancy B. , Suss Matthew E , Bazant Martin Z. 
Published: February 2020

In this project, we demonstrate experimentally and theoretically the feasibility of exploiting deionization shocks in porous media to perform water purification (“shock electrodialysis”, see figure 1). The basic idea of this new approach is to drive an over-limiting current (faster than diffusion) through a weakly charged porous medium sandwiched between two cation-exchange membranes, producing a sharp “shock” (a propagating wave of salt depletion driven by surface conduction [1,2]) in the salt concentration profile within the porous medium [3, 4]. Flowing through the porous medium allows for continuous deionized and brine streams, which can be separated at the outlet. We here will present our work towards the development of a shock electrodialysis device (see figure 2), which enables the desalination of arbitrary feedwater streams, and allows for continuous, fast flows through the device for high throughput desalination. Using this device, we were able to remove up to 99+% of ions from NaCl feed solutions of various concentrations (see figure 3 for data for one specific feed flowrate and concentration). In addition, in order to gain a thorough understanding of the phenomena underlying the system, we performed detailed simulations of the device (see figure 4). This simulation framework will be compared to experimental data and is also used to gain useful engineering insights which are useful in improving the prototypes that we are building. Overall, preliminary results show good desalination factors, reasonable efficiency, and unique separation capabilities, such as removal of particles and disinfection, which may find applications in compact water treatment and brine concentration.
[1] Mani, A.; Zangle, T.; Santiago, J.G. On the Propagation of Concentration Polarization from Microchannel-Nanochannel Interfaces Part I: Analytical Model and Characteristic Analysis. Langmuir 2009, 25 (6), 3898-3908
[2] Zangle, T.; Mani, A.; Santiago, J.G. On the Propagation of Concentration Polarization from Microchannel-Nanochannel Interfaces Part II: Numerical and Experimental Study. Langmuir 2009, 25 (6), 3909-3916
[3] Deng, D.; Dydek, E.V.; Han, J.; Schlumpberger, S.; Mani, A.; Zaltzman, B; Bazant, M. Z. Overlimiting Current and Shock Electrodialysis in Porous Media. Langmuir 2013, 29 (52), 16167-16177
[4] Deng, D.; Aouad, W.; Braff, W.A.; Schlumpberger, S.; Suss, M.E.; Bazant, M.Z. Water Purification by Shock Electrodialysis: Deionization, Filtration, Separation, and Disinfection. Desalination 2015, 357, 77-83

Figure 1
Porous Diamond Membrane Fabricated By Templated Growth for Electrochemical Separation Processes
Authors: Gao Fang , Giese Christian , Lewes-Malandrakis Georgia , Nebel Christoph E. 
Published: February 2020

Boron-doped diamond has been applied as an outstanding electrode material for electrochemical applications. Using templated growth techniques, a variety of diamond nanostructures like diamond wires and diamond foams can be fabricated [1, 2]. Using quartz or glass fiber paper as growth templates, porous diamond membranes are fabricated [3]. Compared to polymer membranes or membranes based on sp2 carbons, diamond membranes can survive in aggressive media and high temperature conditions. Also, the ion selectivity can be controlled by surface terminations as well as the bias potential of the membrane. Therefore, this kind of membranes is very promising for the electrochemical separation processes such as desalination, pollutants concentration and protein separation. However, both the fabrication and application of diamond membranes are so far reported only in very limited cases.
In this paper, we report our recent progress with respect to the templated diamond growth using quartz fiber paper as the growth template. With optimized microwave CVD growth, nanocrystalline diamond film is fully coated onto the quartz fiber as has been confirmed via SEM. The growth conditions in terms of temperature, methane concentration and boron/carbon ratio are investigated in detail. The diamond quality is evaluated via Raman spectroscopy, and the boron concentration is determined via SIMS. The potential window of the diamond membrane is determined via cyclic voltammetry in an aqueous NaClO4 solution to be ~2.5 V. By applying potential to the membrane, ions will accumulate inside the membrane and change its porosity. As a result, the ion flux through the membrane can be well tuned. This ion selectivity can be used to separate charged molecules. As an example, 5-Carboxyfluorescein and substance P are separated by the diamond membrane under different biases. In a neutral solution, for example, negatively charged 5-caboxyfluorescein can penetrate a positively charged membrane, while the positively charged substance P cannot. Therefore, this membrane can potentially be used for separation processes in biochemical and biomedical applications. Finally, due to the robustness of diamond, the membrane can be cleaned via a high potential (+3 V vs Ag/AgCl) oxidation process in 2 M H2SO4. Metal deposits and organic contaminants are proved to be removable by this method. Therefore, this membrane is also suitable for applications like undersea activities where only simple in-situ maintenances are possible.
[1] F. Gao, M.T. Wolfer, C.E. Nebel, Carbon, 80 (2014) 833-840.
[2] F. Gao, G. Lewes-Malandrakis, M.T. Wolfer, W. Müller-Sebert, P. Gentile, D. Aradilla, T. Schubert, C.E. Nebel, Diamond Relat. Mater., 51 (2015) 1-6.
[3] S. Ruffinatto, H.A. Girard, F. Becher, J.C. Arnault, D. Tromson, P. Bergonzo, Diamond Relat. Mater., 55 (2015) 123-130.
Hybrid Films Deposition for Nanochannel Membranes with Functional Surfaces
Authors: Kim Jeong Hwan , Lee Sung-Woong , Jung Sun-A , Yoon Jae-Sung , Yoo Yeong-Eun 
Published: February 2020

Thin film deposition is one of the most significant issues in the fabrication of nano structures. Especially it is difficult to achieve conformal films on high-aspect ratio nanostructures, such as nanochannel membranes. Though there are various thin film deposition techniques, atomic layer deposition (ALD) has attracted due to its extreme surface conformality and excellent thickness controllability. Because ALD is a chemical gas phase thin film deposition method based on sequential and self-saturating surface reactions, it can be used for coating of nano structures with high-aspect ratio.
Sputtering process is one of the popular film deposition techniques due to its relative simplicity of process and fast deposition speed. However, film depositions by sputtering technique are less conformal compared to those by ALD, because of ions directionality sputtered by plasma. Therefore it is difficult to form films on the surfaces perpendicular to substrate by sputtering process.
However, if ALD and sputtering techniques are combined, hybrid thin films deposition which different films are deposited on selectively different surfaces (eg. surfaces perpendicular and parallel to substrate). In this poster, I will present the results of hybrid films deposition on nanochannel membranes with high-aspect ratio. For different functionalities (hydrophilicity and hydrophobicity) of surfaces, Al2O3 and Pt films were grown on nanochannel membranes. Al2O3 films deposition on the vertical surfaces (inner surfaces of nanochannels) was controlled precisely in nanometer scale by using ALD process. Pt films were formed on horizontal surfaces (outer surfaces of nanochannels) by using DC magnetron sputtering. In addition, I will also present the ionic seperation in NaCl solution using fabricated nanochannel membranes by hybrid deposition process and using electrcal bias on Pt films.
Spectroscopic Ellipsometry Characterization of Pd Thin Film Grown by Atomic Layer Deposition
Authors: Zhang Yihang , Zhou Xueqi , Cao Kun , Chen Xiuguo , Liu Shiyuan , Shan Bin , Chen Rong 
Published: February 2020

Ultrathin noble metal films have attracted lots of attentions in fuel cell catalysts, hydrogen storage, emission control, etc. Among many synthesis methods, atomic layer deposition (ALD) is a powerful one to fabricate ultrathin films with great precision [1]. The measurement of such noble metal films is quite important to both understand the initial growth behavior and guide the film fabrication process. Spectroscopic ellipsometry (SE) is a fast and non-destructive thin film characterization technique with atomic sensitivity [2]. The initial growth of noble metals, however, is in island growth mode and bulk metal model could not correlate with such structures. Similar structures have been reported by the Maxwell-Garnett Effective medium approximation (MG-EMA) model to study the optical properties of Au, Ag thin films [3-4]. In this paper, we choose the MG-EMA model with General oscillator (GO) to study the size and volume fraction.
In this study, MG-EMA model has been chosen to study Pd ultrathin film grown on Si substrate, as well as its growth on self-assembled monolayers (SAMs) modified substrate respectively. The GO model with one Drude and two Lorentz oscillators is firstly applied to fix the optical constants of Pd. Compared with Pd bulk model, MG-EMA model with GO is more reliable to predict the film thickness verified by X-ray reflection test. The stable growth rate on Si substrate reveals our methods are feasible and is in accordance with the quartz crystal microbalance measurement. For Pd coverage, MG-EMA fitting result is similar with the statistical computation from scanning electron microscope when cycles of Pd ALD cycles are over 400, while large bias exists for cycles under 400, might be due to that air is not the proper filling medium between nanoparticles. Then we change the filling medium into SAMs as a comparison, better fitting performance is obtained. It is demonstrated that the filling medium between nanoparticles is important for the application of MG-EMA model.
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H. Feng, J. Lu, P. C. Stair, J. W. Elam. Catal. Lett, 141, 512-517(2011).

K. Vedam, Thin Solid Films, 313, 1-9(1998).

K. C. See, J. B. Spicer, J. Brupbacher, D. Zhang, T. G. Vargo, J. Phys. Chem. B, 109, 2693-2698(2005).

T. Ung, L. M. Liz-Marzán, P. Mulvaney, J. Phys. Chem. B, 105, 3441-3452(2001).
(Invited) A Rational Design for Batteries at Nanoscale by Atomic Layer Deposition
Authors: Liu Chanyuan , Gillette Eleanor , Chen Xinyi , Pearse Alexander J , Kozen Alexander C , Schroeder Marshall A , Gregorczyk Keith , Lee Sang Bok , Rubloff Gary W 
Published: February 2020

A self-aligned nanostructured battery fully confined within a single nanopore presents a powerful platform to determine the rate performance and cyclability limits of nanostructured storage devices. Atomic layer deposition (ALD) has enabled us to create and evaluate such structures, comprised of nanotubular electrodes and electrolyte confined within anodic aluminum oxide (AAO) nanopores as “all-in-one” nanopore batteries.This nanopore battery displays exceptional power-energy performance and cyclability when tested as massively parallel devices (~2billion/cm2), each with ~1um3 volume (~1fL). [1]
The unprecedented thickness and conformality control of ALD and the highly self-aligned nanoporous structure of anodic aluminum oxide (AAO) are essential to enable fabrication of precision, self-aligned, regular nanopore batteries. To realize such structure, we began with fine tuning of ALD process conformality inside high aspect ratio (300:1) AAO nanopores. Ru/Pt metal is optimized to be 15µm deep at both sides of 50µm long AAO pores in order to provide fast electron transport to overlying V2O5 at both anode and cathode sides, while keeping them spatially and electrically isolated. Crystalline V2O5 was deposited as active storage material inside the metal nanotubes using O3 as the oxidant. Then the V2O5 was electrochemically prelithiated at one end to serve as anode while pristine V2O5 without Li at the other end served as cathode, enabling the battery to be cycled between 0.2V and 1.8V. Capacity retention of this full cell is 95% at 5C rate and 46% at 150C, with more than 1000 charge/discharge cycles. Further increase of full cell output potential is also demonstrated for SnO2 and TiO2 anodes in asymmetric full cells with V2O5cathodes. These results demonstrate the promise of ultrasmall, self-aligned/regular, densely packed nanobattery structures as a test bed to study ionics and electrodics at nanoscale with a variety of geometrical modifications and as a building block for high performance energy storage systems.

[1] Liu, C.; Gillette, E. I.; Chen, X.; Pearse, A. J.; Kozen, A. C.; Schroeder, M. A.; Gregorczyk, K. E.; Lee, S. B.; Rubloff, G. W., An all-in-one nanopore battery array. Nature Nanotechnology
2014,
9 (12), 1031-1039.
(Invited) Organic-Inorganic Hybrid Materials Formed By ALD Organometallic Infiltration into Polymers
Authors: Jur Jesse S , Akyildiz Halil Ibrahim 
Published: February 2020

Atomic layer deposition on polymers has been demonstrated to yield infiltration of reactive vapors that react with the polymer to form hybrid organic-inorganic materials structures. From this infiltration, new dosing schemes have been utilized to elicit controlled reaction and diffusion. Inspection of these materials has shown a unique set of characteristics, including the ability to fabricate optically active hybrid materials as a result of the formation of a bandgap. As an example process, we examined the ability to infiltrate trimethylaluminum into polyethylene terephthalate (PET) using elongated sequential exposures. As a consequence of PET-AlOx coordination complex formation within the PET polymer (in film and fiber form), semiconductor behavior is observed in modified material; hence a novel approach toward modifying the band structure of organic materials for optoelectronic and electronic applications. Furthermore, the photoluminescence behavior of the modified PET is shown to increase up to 13 fold while internal quantum efficiency (IQE) values increased from ~4-5% up to ~25% in the UV spectrum. Photocatalytic applications have been explored for these materials for their ability to reduce metal ions, such as Ag and Au, out of aqueous salt solutions during UVA light exposure. As a result of this photoreduction process, patterned metallic structures are formed that are useful for flexible electronic and e-textile device systems.
Sulfate Adsorption onto and Desorption from Silicon Dioxide Films
Authors: Wu Bing , Raghavan Srini 
Published: February 2020

Sulfuric acid, especially in a mixture with hydrogen peroxide, is a commonly used chemical in the surface preparation of silicon. Removal of adsorbed sulfate based contaminants by DI rinsing is an important step in processing steps using sulfuric acid. Fundamental information on the rate and extent of adsorption and desorption of sulfate on surfaces is very scarce.
This presentation will discuss sulfate adsorption onto and desorption from SiO2 surfaces using a quartz crystal microbalance with dissipation monitoring capability (QCM-D). The amount of adsorption of sulfate was estimated from frequency shifts of a SiO2 coated AT-cut quartz crystal. The quartz crystal, with a fundamental frequency of 5 MHz, consists of a quartz disk of 14mm diameter, and gold electrodes that are sputtered on both sides of the quartz disc. The SiO2 coating, 300 nm thick, was deposited by PVD onto the active side of quartz crystals.
Figure 1 shows a real time frequency recording of a SiO2 coated crystal exposed to flowing 0.2 M sodium sulfate solution. The frequency and dissipation change were measured for different harmonics of the fundamental crystal frequency at the same time. The divergent overtones and high dissipation factor indicated a “soft” adsorbed layer, rendering the Sauerbrey relation invalid for mass calculation from frequency changes. Hence, a viscoelastic model was used for conversion of frequency changes to mass changes. It can be seen the sulfate adsorption onto and desorption from SiO2 surface happens fairly quickly as marked in the figure. At 22 C, the rate constants of desorption are about 0.06 s-1 and 0.16–0.18 s-1 for flow rates of 0.2 ml/min and 1.0 ml/min respectively.
The adsorption isotherm of sulfate is shown in figure 2. The equilibrium adsorption increases linearly with sulfate concentration at the range of 0.1 M to 0.6 M.

Figure 1
(Invited) Advanced Nanostructured Thermoelectric Materials for Energy Conversion
Authors: Wu Yue 
Published: February 2020

The rapid development of nanomaterials in the past decade has provided a possibility of directly converting waste heat back to electricity based on the thermoelectric Seebeck effect. In the past four years, we have developed a transformative approach to pioneered low cost and scalable solution-phase growth methods to mass produce thermoelectric nanowires and nanowire heterostructures to match the physical and economic magnitudes of energy use and economical entertainment in the manufacture/recycling. These nanostructured thermoelectric materials show a significantly enhanced performance compared to the bulk crystals based on the quantum confinement and minority carrier blocking.