bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphitic Carbon Nitride (g-C3N4) Modified N-Doped LaTiO3 As an Organic–Inorganic Hybrid for Higher Visible Light Photocatalytic and Photo-Electrochemical Performance
Authors: Rakibuddin MD , Shinde Mahesh Ashok , Kim Haekyoung 
Published: February 2020

Photocatalysis mimics natural photosynthesis by converting solar energy into chemical energy, and hence, it has tremendous potential to be an alternative sustainable means for dealing with global energy crisis and environmental remediation. LaTiO3 is an important rare-earth-metal-based perovskite semiconductor, but unfortunately, the visible light photocatalytic and photocurrent activity of LaTiO3 has been rarely studied. In the present work, we report interesting results on enhancing visible light photocatalytic and photocurrent activity of LaTiO3
via N-doping and making heterojunction with metal free g-C3N4. We synthesized the g-C3N4 modified N-doped LaTiO3 (CLT) organic-inorganic hybrid via a sol-gel polymerized complex method followed by facile solid state transformation route. The synthesized hybrids are thoroughly characterized. The CLT hybrid exhibits not only longer wavelength absorption in the visible region but also an enhancement in the catalytic activity under visible light compared to pure N-doped LaTiO3 and g-C3N4. The improved visible light activity of the CLT hybrid is ascribed by its suitable band edge potential and better separation of photoinduced charge carriers through the heterojunction of g-C3N4 and N-LaTiO3. Based on the results of photoluminescence, electrochemical impedance, and radical scavenger studies, a possible photocatalytic mechanism for the hybrid is also proposed. The photostable and reusable CLT hetero-structure is expected to provide new insight for the application of organic-inorganic hybrid and perovskite in light energy conversion and could be suitable for water splitting under sun light as well.
Reference: 1. Appl. Surf. Sci. 2018, 452, 400-412

2. Angew. Chem. Int. Ed.
2017, 56, 2064–2068.
Fujimi’s New SiC CMP Slurry Development
Authors: Hirano Shinya , Takami Shinichiro , Noguchi Naoto , Ishibashi Tomoaki , Ito Yasuaki , Oda Hiroyuki , Arakawa Shigekazu , Mori Yoshio , Greene Bill , Sanford James , Riesen Jon , Kato Tomohisa 
Published: February 2020

Introduction
Since silicon carbide (SiC) is a very hard substrate and is stable both chemically and physically, wafer processing is costly and takes a lot of time. Particularly, in the chemical mechanical polishing (CMP) process, which is the final wafering process, significant improvement in performance such as surface quality and productivity is required for high volume commercial production.
At Fujimi, we have developed a high removal rate slurry of over 1.5 μm per hour on the Si-face under neutral pH and conventional CMP processing conditions. We have also proven that the slurry had a nice behavior in removal rate performance based on Prenston equation, that is, removal rate was proportional to the pressure and velocity of substrate. Furthermore, our testing result has shown great surface morphology such as no scratches and no latent scratches beneath the surface. Low surface roughness was achieved under 0.1nm of RMS at 10x10μm area.
Fujimi has introduced this new SiC slurry at the Advanced Industrial Science and Technology (AIST) as a suitable stock polishing slurry to remove surface damage coming from previous grinding or lapping steps. We have demonstrated the benefit of a two-step CMP process which applies a stock step using the higher removal rate slurry followed by a fine step using our Colloidal silica type slurry. As a result, the combination process could realize to produce the SiC epi-ready wafer with fine quality surface in shorter process time than conventional process [1].
Results and Discussion
In this study, we will discuss our SiC slurry development technologies. At Fujimi, we can control the size and shape of the abrasive grains. Utilizing our expertise in chemical and additive formulation, we can modify our slurries to meet our customers’ various performance criteria.
In Figure 1, it shows a test result example in which the removal rate of the Si-Face was improved. These improved performances depended on the type of additive used in the slurry.　Test was performed using substrates of 4-inch 4H-N SiC (4°off) Si-face substrates with exactly the same polishing process and pad condition for all slurries.　Slurry A was a result of high speed conventional slurry used by AIST [1] as a reference slurry. Slurry B was a newly developed slurry with improved abrasive grains dispersion. Slurry C was also a newly developed slurry focusing on the improvement of oxidation efficiency. As a result, it was possible to achieve a polishing removal rate over 2 um / hour as well as maintain low surface roughness at the same time.
[1] S. Hirano et al., Journal of the Japan Society for Abrasive Technology, 60, (2016)353

Figure 1
Effects and Characterizations of Pulse Electrodeposition Parameters of Silver on Surface Roughness and Scattering Parameters of Horn Antennas
Authors: Başaran Caner , Karakaya Ishak 
Published: February 2020

Electronic conductivity is a parameter that exhibits the free-electron transportation ability of a material. The radiation efficiency of reflector type antennas and insertion loss of waveguide transmission lines are directly related to the conductivity of the materials used to construct such structures. Signal quality of antenna and waveguides in the transmission of electromagnetic waves are also very much dependent on the surface finish that has good conductivity [1].
The use of pulse currents produces homogenous deposits of better surface finish than direct current [2,3]. Effects of pulse parameters on the surface properties of silver coatings of the copper base material have been analyzed in terms of surface roughness and S-parameter (scattering parameter). Grain morphologies of silver coatings were characterized by SEM and XRD. The duty cycle, frequency and the average current density were selected as three pulse parameters. Three levels were selected for each parameter in the experimental design. A relationship was developed for surface finish in terms of duty cycle, average current density and pulse frequency. The S11 scattering parameter observations were made relative to a gold-plated reference coupon. It was analyzed that smoother surfaces had more reflection power in terms of S11 parameter thus decreasing the loss of radiation. Therefore, the results may be used to develop a silver coating procedure to improve signal quality of antenna and waveguides in the transmission of electromagnetic waves.
[1] Balanis, C. A. (1989), “Advanced Engineering Electromagnetics”, John Wiley & Sons
[2] Chandrasekar, M.S. and Pushpavanam, M. (2008) ‘Pulse and pulse reverse plating—Conceptual, advantages and applications’, Electrochimica Acta, 53(8), pp. 3313–3322.
[3] Arslan, B., Demirci, G., Karakaya, İ. and Erdoğan, M. (2015) ‘Formation of gold-plated electroformed copper structures’, Advances in Materials and Processing Technologies, 1(3-4), pp. 384–393.
High Temperature Oxidation Resistance of Cr Coatings on 22MnB5 Steel Electroplated in Trivalent Cr Baths
Authors: Huang Chao-Yu , Lin Chao-Sung 
Published: February 2020

22MnB5 steel is one kind of advanced high-strength steels commonly used for vehicles to enhance passengers’ safety and reduce carbon dioxide emission[1]. However, 22MnB5 steel is vulnerable to high-temperature oxidation and a protective coating is essential to inhibit oxidation during hot stamping process. For example, hot-dip Al-10 wt % Si coating has been extensively applied on press hardening steel although it does not provide sacrificial protection on the steel parts[2]. In contrast, hot-dip Zn coating, which confers sacrificial protection, tends to suffer oxidation and liquid metal embrittlement during hot stamping[3, 4].
This study investigated the structure and properties of Cr coatings on 22MnB5 steel electroplated in a trivalent Cr (Cr(III)) bath. The DC electroplating was conducted in a chloride-based Cr(III) electrolyte with and without the addition of sulfur-containing organic compounds. The morphology, microstructure, and composition of the Cr coating were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), and electron dispersive spectroscopy (EDS). The thickness of the deposit before and after high-temperature heat treatment (900℃ for 5 min in air) was measured using cross-sectional SEM.
Experimental results show that the sulfur-containing organic compound in the electrolyte reduces the carbon content and increases the sulfur content of the Cr coating, which, in turn, reduces the residual stress of the coating. As a result, a crack-free Cr coating can be obtained in the electrolyte with the organic additive. In contrast, many cracks develop on the Cr coating plated in the electrolyte without the organic additive. After the heat treatment at 900℃ for 5 min, extensive oxidation was observed on the crack-free Cr coating, but not on the Cr coating with cracks. It is likely that the presence of sulfur in Cr coating deteriorates the oxidation resistance. Crack openings of the Cr coating free of sulfur are filled with compact oxides after 900℃heat treatment for 5 min. The steel substrate with a Cr overlay remains intact, indicating the Cr coating prevents the steel substrate from oxidation at 900℃.Finally, a 2-mm-thick Cr coating can be electroplated in the Cr(III) bath without the organic additive at a current density of 10 A/dm2and a plating time of 1 min and effectively protects the 22MnB5 steel from high-temperature oxidation.
Reference
[1] H. Karbasian, A.E. Tekkaya, Journal of Materials Processing Technology, 210 (2010) 2103-2118.
[2] D.W. Fan, H.S. Kim, J.-K. Oh, K.-G. Chin, ISIJ international, 50 (2010) 561-568.
[3] C.W. Lee, D.W. Fan, I.R. Sohn, S.-J. Lee, B.C. De Cooman, Metallurgical and Materials Transactions A, 43 (2012) 5122-5127.
[4] M. Razmpoosh, A. Macwan, E. Biro, D. Chen, Y. Peng, F. Goodwin, Y. Zhou, Materials & Design, (2018).
Influence of ZrO2 Incorporation into Coating on Electrochemical Response of Low-Carbon Steel Processed By Plasma Electrolytic Oxidation
Authors: Lee Kang Min 
Published: February 2020

The carbon steel is one of the most widely used metals material in engineering with good properties, such as high strength, high toughness, good mechanical properties and low cost. The surface treatment of the steel is essential, however, before use it in industry due to the low corrosion resistivity of steel substrate, which is a problem to use in high humid environment. Meantime it is important to improve the wear resistance and the interfacial adhesion of the coating. Since the thick alumina coating is one of most effective anti-corrosion layer which has high corrosion resistance relatively with the metals, the alumina coating on the steel substrate is good way to improve corrosion resistance. Among the ceramic coating technique for fabrication the alumina layer, such as chemical vapor deposition, magnetron sputter and ionization-assisted beam, plasma electrolytic oxidation (PEO) has been investigation as a new electrochemical surface treatment.
PEO process is a unique process that utilized electrochemical reactions to form an oxide layer on a metal surface. The PEO process has been reported to attractive combination of wear resistance and corrosion resistance as well as enhancing thermal property of coating layer. However this advanced coating technique has been performed only if material was valve metals, such as Mg, Al, Ti, Nb and etc. and only a few papers of PEO processed steel have been published. Although several researchers performed PEO process on the steel substrate, the specimen was pretreated by plasma spray, laser re-melting or chemical vapor deposition, therefore it was not convenience to widely use in engineering due to the very high cost and thermal shock to the substrate.
The structure and morphology of coating layer formed by PEO process, on the other hand, is influenced on experiment conditions which are composition and concentration of electrolyte, current density and condition of substrate, in particular, composition of electrolyte effect on forming oxide layer. Recently, the incorporation of second oxide nanoparticles into the oxide layer generated by the PEO process in order to improve functionality has received considerable attention. Our previous work has demonstrated that incorporated ZrO2 nanoparticles into oxide layer may enhance the resistance against pitting corrosion.
In this study, we conducted PEO process on A36 carbon steel without any pretreatment and successfully formed an incorporated alumina layer with 200-400 nm size of ZrO2 nanoparticles on the carbon steel and prepared comparison specimen which is unincorporated alumina coating with any others during PEO process. The microstructure and phase of coating layers were investigated and corrosion behavior was evaluated by electrochemical impedance spectroscopy.
Electrochemical Behavior and Extraction of Yttrium on Cu Electrode in LiCl-KCl Eutectic
Authors: Li Wenlong , Han Wei , Li Mei , Yang Xiaoguang , Sun Yang 
Published: February 2020

The electrochemical behaviors of Y(III) were investigated on inert W and reactive Cu electrodes in LiCl-KCl eutectic by electrochemical technique at 773K. On an inert W electrode, the apparent standard potential of Y(III)/Y(0) couple was studied at different concentration of Y(III) ions using cyclic voltammetry. The result shows the apparent standard potential of Y(III)/Y(0) couple has a dependent on the concentration of Y(III) ions. On a reactive Cu electrode, cyclic voltammetry, stripping voltammetry and square wave voltammetry experiment results indicated that the deposition potential of Y (III) shift toward more positive values than that on W electrode because of the formation of Cu-Y intermetallic compound. Five Cu-Y intermetallic compounds, Cu6Y, Cu4Y, Cu7Y2, Cu2Y and CuY, were found to be formed by transient and steady electrochemical methods. Based on open circuit chronopotentiogram, the intermetallic compounds of Cu7Y2 is easier to form and more stable than the others because its platform is longer. Potentiostatic and galvanostatic electrolysis was conducted on Cu electrode to extract metallic yttrium. Furthermore, the cyclic voltammetry curves showed that the redox signals observed before electrolysis almost disappeared after electrolysis. In addition, the concentration of Y(III) ions in LiCl-KCl melts were detected by inductive coupled plasma atomic emission spectrometer before and after electrolysis, and the current efficiency for the electroextraction of Y was estimated. The results showed that Y(III) ions could be effectively extracted using reactive Cu electrode. Finally, the electrolysis products were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results showed that yttrium and copper can form Cu-Y intermetallic compounds during electrolysis and the thickness of alloy layer is about 50 mm.
Acknowledgement
The work was financially supported by the National Natural Science foundation of China (11675044, 11575047, 21790373, 21271054 and 21173060), the Major Research plan of the National Natural Science Foundation of China (91326113 and 91226201), and the International Exchange Program of Harbin Engineering University for Innovation−oriented Talents Cultivation.

Figure 1
Size-Effects of Micropattern on Lithium Metal Surface on the Electrochemical Performance of Lithium Metal Secondary Batteries
Authors: Kim Dohwan , Park Joonam , Jin Dahee , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

As lithium (Li) metal has a low reduction potential (-3.045 V vs. SHE) and a high capacity per weight (3860 mAh g-1), Li has been researched continuously as one of the fine secondary battery anode materials. However, there are some electrochemical issues that Li metal’s charge/discharge efficiency is lower than those of conventional carbon-based anode materials, and Li is intensively grown at a specific region of the Li surface and form a dendritic dendrite. Dendrites not only increase the dead Li but also lead to an internal short to cause a battery explosion. In order to solve this problem, this research group has reported that micropatterns can be formed on the surface of Li metal to successfully control Li plating/stripping position behavior
In this study, we investigated how the pattern controls the shape of Li according to the charging/discharging current density, and the effect of the pattern size change on the electrochemical properties of the battery. Micropatterns of two sizes, 50 and 80 μm, are designed to have an available capacity of 1.06 and 2.44 mAh cm-2, respectively. We fabricated a micropatterned Li metal with two effective capacities and made a Li/Li symmetric cells to analyze the overpotential characteristics. The overpotential characteristic of 80 μm-patterned Li was lower than that of 50 μm-patterned Li during long charge. Also, full cells (LiNi0.6Co0.2Mn0.2O2 / 2 mAh cm-2) were fabricated with each patterned Li metals. As a result, 80 μm-patterned Li showed stable morphologic behavior inside pattern and exhibited much better electrochemical performance.
Onion-like Synergetic Multilayer Coating for High-Stability Silicon Monoxide Anode in Lithium-Ion Batteries
Authors: Tan Tian , Lee Pui-kit , Yu Denis Yau Wai 
Published: February 2020

Silicon monoxide (SiO) is a potential next-generation high-capacity anode material for lithium-ion batteries. However, SiO undergoes severe volume change during charge and discharge, which leads to mechanical failure and thus fast capacity decay. Nano-structuring has been reported as an effective method to improve cycle stability of SiO by preventing particle pulverization and increasing void content to accommodate the large volume change. Though, nano-particles are difficult to handle and energy-intensive to manufacture in large scale. In addition, the larger surface area facilitates side reactions between active material and electrolyte. Therefore, the use of micron-size materials is desirable.
Herein, we engineer a multilayer surface coating on micron-sized (5 µm) carbon-coated SiO particles (SiO@C) to enhance the stability of the electrode during charge and discharge. The layer of carbon on SiO@C enhances its electrical conductivity. The material is treated with ultra-violet irradiation to generate -OH functional groups on its surface. The resulting particles are treated with an organosilane self-assembled monolayer (SAM) with (3-aminopropyl)triethoxysilane (APTES). The powder is then further combined with imide monomers and heat-treated to form a robust chemical bonding between the amine (-NH2) functional group of the SAM and the dianhydride group of the polyimide (PI) on the surface. The resulting SiO@C@UV@NH2@PI composite possesses excellent mechanical stability, where the high-modulus PI layer suppresses volume change, particle pulverization and electrode cracking during charge and discharge. In addition, the PI coating reduces side reactions between the electrolyte and the active material and improves the Coulombic efficiency of the electrode.
Our study demonstrates that the SiO@C electrode with the multilayer coating exhibits a stable capacity of 1310.7 mAh g-1 after 100 cycles at 150 mA g-1, and a capacity of 910.3 mAh g-1 (capacity retention 94.2%, with respect to the 2nd cycle) under 1 A g-1 after 300 cycles. In comparison, SiO@C electrode without surface coating gives only a reversible capacity of 247.1 mAh g-1 after 100 cycles, with a 15.1% capacity retention (see Figure 1a). Figure 1b shows a comparison of the thickness change of the two SiO electrodes during charge-discharge, verifying that the multilayer coating can reduce volume expansion. Further characterizations of the surface-coated material to identify the mechanism of the improvement are underway and more data will be presented at the meeting.

Figure 1
Pre-Electrochemical Treatment Effect of Cu Eqcm Electrode on Lithium Electrodeposition/Dissolution Processes
Authors: Kondo Toshihiro , Smaran Kumar Sai , Ohama Ayano , Niida Asako , Nishihara Kaho 
Published: February 2020

Lithium has been extensively expected as one of the most ideal anode materials of the next generation lithium-based batteries, because of its higher theoretical specific capacity (3860 mA h g-1) and its most negative redox potential (-3.04 V vs. SHE). On the lithium anode surface, however, it is well known that the dendrite, which further leads to poor performance and short circuit, forms. In addition, solid electrolyte interphase (SEI), which is generated by decomposition of electrolytes and/or solvents, also accumulates on the anode surface during the anode reaction. An ideal SEI layer is expected to be higher and lower conductive for lithium ion and electron, respectively, and it is flexible and has a relatively uniform flat surface with an appropriate thickness, in order to avoid dendrite formation [1].
During the electrochemical reaction, on the other hand, electrochemical quartz crystal microbalance (EQCM) technique gives us information not only of mass change on the electrode surface but also resonance resistance change, which shows surface area change of the electrode [2,3] and/or density and viscosity change at the electrode/electrolyte solution interface [4,5]. Using this technique, we found that the pre-electrochemical treatment of Cu EQCM electrode strongly effects on the lithium electrodeposition/dissolution processes.
Acknowledgements
This work was totally supported by the Advanced Low Carbon Technology Research and Development Program (ALCA), specially promoted research for innovative next generation batteries (SPRING) from the Japan Science and Technology (JST).
References:
[1] X.-B. Cheng, R. Zhang, C.-Z. Zhao, F. Wei, J.-G. Zhang, Adv. Sci.3 (2016) 1500213.
[2] K. Kanamura, S. Shiraishi, Z. Takehara, J. Electrochem. Soc.147 (2000) 2070.
[3] D. Aurbach, M. Moshkovich, Y. Cohen, A. Schechter, Langmuir15 (1999) 2947.
[4] K. Naoi, M. Mori, Y. Naruoka, W. M. Lamanna, R. Atanasoski, J. Electrochem. Soc.146 (1999) 462.
[5] N. Serizawa, S. Seki, K. Takei, H. Miyamoto, K. Yoshida, K. Ueno, N. Tachikawa, K. Dokko, Y. Katayama, M. Watanabe, T. Miura, J. Electrochem. Soc.160 (2013) A1529.