Abstract: A mosaic design of diamond disks that incorporates different cutting characteristics of diamond grits can allow faster polishing of wafers with less pad consumption. Larger diamond grits can make pad asperities with large peak to valley ratios for achieving high polishing rate. On the other hand, Sharp grits can shave the pad effectively as to eliminate the glazed layer. The conventional diamond disks employ similar type of diamond grits across the entire disk. These grits cannot dress and cut the pad with optimization. By combining different types of diamond grits in a cocktail combination, the pad asperities can be controlled to enhance removal rates of the wafer. The glazed layer may also be removed cleaner so wafer defectivity is minimized.

Abstract: Electrochemical oxidation is a promising candidate for decentralized wastewater treatment, due to its modular design, convenient operation, and small carbon footprint. In this process, pollutants are oxidized at the anode, while valuable hydrogen is produced at the cathode. Different from water splitting, the ideal anodes in EO process should have high activity toward oxidant generation rather than oxygen evolution. The need to develop highly efficient and durable anode material is a never-ending challenge. Chloride, as a ubiquitous component in wastewater, can be oxidized readily to reactive chlorine species (RCS = OCl ­- , HOCl, Cl·, and Cl 2 · - ) to remove pollutants such as organics, ammonium and bacteria. However the speciation of RCS in saline water electrolysis is lacking of quantitative description. The contribution of each RCS species to pollutant removal is still under debate. The first approach of this study is to develop multi-layer heterojunction anode for RCS generation. IrO 2  is an excellent catalyst for water splitting. By depositing a thin film of TiO 2 on IrO 2  (Ti/Ir), the oxygen evolution reaction is hindered while the selectivity toward chlorine production is greatly enhanced. The further deposition of Sb-SnO 2 islands on TiO 2 layer (Sn/Ti/Ir) provides additional active sites for radical generation.  As our second approach, a computational kinetic model covering chlorine generation and radical production is established. Combing it with experimental data, chlorine evolution and the furuther oxidation of chlorine to ClO 3 - and ClO 4 - on Ti/Ir anode can be simulated. It is found that Cl·and HO· is produced concomitantly with chlorine on Sn/Ti/Ir anode and Cl 2 · - is the dominant radical after reaching equilibrium. The rate constant of Cl· production is two to three orders of magnitude lower than that of chlorine generation. The model predicts that the increase of chloride concentration will enhance the chlorine production but quench more radicals, which is in consistance with experimental results. The best performing Sn/Ti/Ir anode was applied to human wastewater electrolysis. Although Cl 2 · - is more oxidative than chlorine, chlorine is the major contributor to the removal of organics and ammonium due to its higher concentration. Figure 1

Abstract: Technology has advanced rapidly, especially in the 21st century, influencing our daily life on unprecedented levels. Most such advances in technology are closely linked to, and often driven by, the discovery and design of new materials. Many researchers have been actively searching for alternative cathode materials for Lithium-ion batteries (LIBs) that can be more clean, efficient, cost-effective, and deliver higher electrochemical performance compared to the already-commercialized electrodes. However, finding new and effective energy storage technologies is a particularly daunting task, even for a very experienced researcher. Computational compilation of battery materials properties such as voltage, diffusivity, and phase stability against irresponsible phase transformations using first-principles density functional theory (DFT) calculations has helped understand the underlying mechanism in many existing and hypothetical compounds that can be used as a part of battery components. By computationally modeling the spinel LiMn 2 O 4 surface structures, we were able to provide a novel strategy to suppress Mn dissolution and the Jahn-Teller distortion associated with Mn 3+ , particularly at the (001) LiMn 2 O 4 facet, which has been a challenging task to overcome in order to mitigate capacity fading in the Mn-based cathodes [1-3]. In addition, the idea of a multi-faceted high-throughput screening within the Open Quantum Materials Database (OQMD) [4,5] was carried out to discover a number of new Li-rich Li 2 MO 3 -type layered compounds (beyond Li 2 MnO 3 ) to narrow down the list of thousands of candidate composite electrodes to a handful that are the most likely to be synthesized in experiment [6]. We classified the family of discovered Li 2 MO 3 compounds as active cathodes or inactive stabilizer and have suggested the top-30 Li 2 M I O 3 -Li 2 M II O 3 active/inactive pair cathode systems (M I, M II = transition- or post-transition-metal ions) by examining the properties with respect to their operating voltage, stability against oxygen loss and metal migration, and the formation of solid-solution and/or coherent nanocomposites [6]. Our computational predictions have included at least a dozen new Li-rich cathode pairs with higher gravimetric energy densities compared to recently-discovered Ru-based Li 2 MO 3 cathodes, which might have varying degrees of practical vs. purely scientific interest due to cost or toxicity reasons. Currently, there is an on-going investigation in order to verify whether these computational predictions can be realized in experiment and the further details will be discussed at the upcoming meeting. Furthermore, our recent study prompted a re-investigation of lithiated spinel (Li 1+ x Co 2 O 4 ; 0 〈 x ≤ 1) and Li 2 Co 2- y Ni y O 4 (0 〈 y ≤ 0.4) with the argument that a lithiated cobalt-containing oxide spinel component embedded in a layered-layered-spinel composite electrode would benefit in terms of both delivered voltage and cycling stability, when compared to a manganese-based spinel oxide [7,8]. In order to understand the electrochemical performance of Li-Co-O cathodes synthesized at different temperatures, we revisited the phase stability of Fd-3m and R-3m LiCoO 2 using DFT calculations [9]. In addition, a structural search of Fd-3m Li 2 Co z M 2- z O 4 (0 ≤ z ≤ 2) lithiated-spinel (M' = Ni or Mn) structures and compositions was conducted to extend the exploration of the chemical space of Li-Co-Mn-Ni-O electrode materials, where we have predicted a new lithiated-spinel based composition lying on the convex hull ( i.e. , thermodynamically-stable) that may have potential for exploitation in structurally-integrated, layered-spinel cathodes for next-generation LIBs [9]. Lastly, our recent alternative synthesis approach to prepare each cathode material separately and to integrate two- or three-component cathode via a high-energy ball-milling process will be presented [10-14], which could be simple, robust, cost effective, rapid, and scalable at industrial scale, as well as it can synthesize a number of new closely-connected nanocomposite systems with the difficulty in preparing phase-pure materials. This simple synthesis method could bring a new perspective on the preparation and use of the high-energy-density cathode material systems, consisting of more than two components. References: S. Kim, et al. , Phys. Rev. B , 92, 115411 (2015). L. Jaber-Ansari, et al. , Adv. Energy Mater. , 5 , 1500646 (2015). K. -S. Chen, et al. , Nano Lett. , 17 , 2539 (2017). J. E. Saal, et al. , JOM , 65 , 1501 (2013). S. Kirklin, et al. , npj Computational Materials , 1 , 15010 (2015). S. Kim, et al. , Energy Environ. Sci. , 10 , 2201 (2017). E. Lee, et al. , ACS Appl. Mater. Interfaces , 8 , 27720 (2016). S. Kim, Electrochem. Soc. Interface , 25 , 96 (2016). S. Kim, et al. , in preparation. S. Kim, et al. , J. Power Sources , 220 , 422 (2012). S. Kim, et al. , J. Mater. Chem. , 22 , 25418 (2012). J. -S. Yun, et al. , Bull. Korean Chem. Soc. , 34 , 433 (2013). J. -K. Noh, et al. , Sci. Rep. , 4 , 4847 (2014). S. Kim, et al. , ACS App. Mater. Interfaces , 8 , 363 (2016). Figure 1

Abstract: Hollandite α-MnO 2 , with an open tunnel structure, is of interest as a cathode material for 3 V lithium batteries [1,2] and as an electrocatalyst for Li-O 2 cells [3]. We recently proposed [4] that α-MnO 2 belong to a class of materials that can be used as the cathode in hybrid Li-ion/Li-oxygen battery systems, which can incorporate/release both lithium and oxygen during cycling with redox reactions occurring on both the transition metal ions and oxygen ions of the electrode. In this talk, we will present in-situ and operando characterization and first principles modeling results of α-MnO 2 during electrochemical cycling in conventional lithium cells and in Li-O 2 cells [5,6]. Operando synchrotron x-ray diffraction (XRD) results, combined with first principles density functional theory (DFT) modeling, indicate insertion of lithium and oxygen into, as well as partial removal of these species from, the tunnel structure during cycling. On heating hydrated α-MnO 2 , in-situ XRD and Raman studies provide information about structural changes and diffusional properties of the oxygen species in the tunnel structure. DFT studies find low diffusion barriers for H 2 O and H 3 O + species in the tunnel. The implications of the results on other high-capacity, hybrid Li-ion/Li-oxygen materials will be discussed. Acknowledgements This work was supported as a part of the Center for Electrochemical Energy Science, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences under award number DE-AC02–06CH11. Use of the Advanced Photon Source, a US DOE Office of Science User Facility operated by Argonne National Laboratory, was supported by DOE under Contract No. DE-AC02-06CH11357. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. References [1] M. H. Rossouw, D. C. Liles, M. M. Thackeray, W. I. F. David and S. Hull, Mater. Res. Bull., “a-Manganese Dioxide for Lithium Batteries: A Structural and Electrochemical Study,” Mater. Res. Bull., 27 , 221 (1992). [2]  C. S. Johnson, D. W. Dees, M. F. Mansuetto, M. M. Thackeray, D. R. Vissers, D. Argyriou, C.-K Loong and L. Christensen, “Structural and Electrochemical Studies of a-MnO 2 ”, J. Power Sources, 68/2 , 570 (1997). [3] A. Debart, A. J. Paterson, J. Bao and P. G. Bruce, “a-MnO 2 Nanowires: A Catalyst for the O 2 Electrode in Rechargeable Lithium Batteries,” Angew. Chem. Int. Ed., 47 , 4521 (2008). [4]  M. M. Thackeray, M. K. Y. Chan, L. Trahey, S. Kirklin, and C. Wolverton, “Vision for Designing High-Energy, Hybrid Li Ion/Li-O 2 Cells,” Journal of Physical Chemistry Letters 4 , 3607 (2013). [5] L. Trahey, N. Karan, M. K. Y. Chan, J. Lu, Y. Ren, J. P. Greeley, M. Balasubramanian, A. K. Burrell, and M. M. Thackeray, “Synthesis, Characterization and Structural Modeling of High Capacity, Dual-Functioning MnO 2 Electrode/Electrocatalysts for Li-O 2 Batteries,” Advanced Energy Materials 3 , 75 (2013). [6] Yang, L. Trahey, Y. Ren, M. K. Y. Chan, C. Lin, J. Okasinski, and M. M. Thackeray, “In-Situ High-Energy Synchrotron X-ray Diffraction Studies and First Principles Modeling of α-MnO 2 Electrodes in Li-O 2 and Li-ion Coin Cells,” Journal of Materials Chemistry A 3 , 7389 (2015). The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.

Abstract: Abstract not Available.

Abstract: Alpha manganese oxide (α-MnO 2 ) is of interest as a cathode material for lithium-ion batteries and as an electrode/electrocatalyst for hybrid Li-ion/Li-O 2 systems. It has a tunnel structure with large 2x2 channels that accommodate different species such as Ba 2+ , K + , NH 4 + , or H 3 O + /H 2 O. Characterization and modeling of the insertion and removal of Li, oxygen, and H 3 O + /H 2 O species under electrochemical cycling and heating is important for understanding how MnO 2 acts as a hybrid Li-ion/Li-O 2 battery material. In this talk, we will discuss our work in using in-situ synchrotron X-ray diffraction (XRD), X-ray absorption near-edge spectroscopy (XANES), in-situ UV resonance Raman spectroscopy, and density functional theory (DFT) calculations, to unravel the changes in α-MnO 2 during electrochemical cycling as well as dehydration process. We found evidence of oxygen incorporation and partial removal during electrochemical cycling, as well as two-stage water removal during heating. Both processes involve facile oxygen diffusion through the center of 2x2 tunnels. Keywords: MnO2, in-situ XRD, DFT Reference: Z.-Z. Yang, D. Ford, J.-S. Park, Y. Ren, S. Kim, H. Kim , T. Fister, M. K. Y. Chan, # M. M. Thackeray, # “Probing the release and uptake of water in α-MnO 2 •xH 2 O,” Chemistry of Materials 29, 1507–1517 (2017). Z. Yang, L. Trahey, Y. Ren, M. K. Y. Chan, # C. Lin, J. Okasinski, and M. M. Thackeray, “In-Situ High-Energy Synchrotron X-ray Diffraction Studies and First Principles Modeling of α-MnO 2 Electrodes in Li-O 2 and Li-ion Coin Cells,” Journal of Materials Chemistry A 3, 7389-7398 (2015). Acknowledgements: This work was supported as a part of the Center for Electrochemical Energy Science, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences under award number DE-AC02–06CH11. Use of the Advanced Photon Source, a US DOE Office of Science User Facility operated by Argonne National Laboratory, was supported by DOE under Contract No. DE-AC02-06CH11357. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Figure 1

Abstract: Hydroxide membrane fuel cells (HEMFCs) operated in alkaline media enables the use of the non-noble catalyst for oxygen reduction reaction (ORR). Therefore, it seems promising that HEM technology can replace the Pt-metal dependent proton exchange membrane (PEM) technology. However, the sluggish hydrogen oxidation reactions (HORs) on Pt-metal catalysts in the alkaline electrolyte, which are up to two orders of magnitude slower than in the acid electrolyte, requires a higher loading of precious metals on the anode of HEMFCs. This, to a larger extent, offsets the cost gains from employing non-precious metal on the cathode of HEMFCs. In order to tackle this challenge, we prepared Pd 50 Cu 50 alloy nanoparticles (NPs) and characterized them for HOR in 0.1 M potassium hydroxide. The HOR activity exhibited a strong dependence on the annealing temperature. In particular, Pd 50 Cu 50 alloy NPs annealed at intermediate temperature outperforms Pt and Pd. The conventional lab-based XRD shows the annealed Pd 50 Cu 50 alloy features a special crystalline phase. And the synchrotron sources based x-ray further revealed the time-resolved phase change of Pd 50 Cu 50 alloy as the temperature was ramped from 30°C to 950°C. Analysis of STEM and XPS, along with the theoretical modeling based on density functional theory (DFT), provides a new insight into the correlation between the crystalline structure of Pd 50 Cu 50 alloy with HOR activity in alkaline media.

Abstract: Hybrid Li-ion/Lithium-O 2 batteries offer extremely attractive theoretical energy densities and therefore represent a rapidly emerging area of research. Our research has focused on developing dual-functioning metal oxides electrode/electrocatalyst materials that can lower the charge hysteresis and potentially impact the nature of the discharge products. Specifically we have synthesized and characterized the transition metal oxide, α–MnO 2 , which has a hollandite-type structure with relatively large, one-dimensional (1-D) ‘2x2’ tunnels formed by the connection of octahedral [MnO 6 ] units, operates as a superior electrode/catalyst in hybrid Li-ion/Li-O 2 cells. α–MnO 2 generally contains 2~3% of lattice water in the crystal structure, which stabilizes the structure and dramatically influences not only electrochemical properties but also other properties such as density and electronic conductivity. The water can be removed from α-MnO 2 framework by heat treatment without degradation of the structure, and then partially replaced by Li 2 O. The Li 2 O-doped alpha-MnO 2 electrodes, stabilize the structure and provide higher capacities on cycling than the parent material. However, the structure changes of hydrated and dehydrated MnO2 related with electrochemical properties has not been clarified yet.  Herein we report operando temperature-resolved high energy X-ray diffraction experiments performed on alpha-MnO 2 electrodes. The data provides evidence that the crystal structure of α-MnO 2 undergoes reversible changes in lattice parameters and strain during heating and cooling. Insights into reversible changes of tunnel structure of MnO 2 with H 2 O/H 3 O + , as determined by first principles density functional theory calculations, are used to provide a possible explanation for some of the observed results. With the help of the proposed technique, we are expecting to understand the water removal and insertion into MnO­ 2 and generate knowledge on how to improve the sustainability in the practical usage of α-MnO2 as Li and oxides capture medium for hybrid Li-ion/Li-O2 cells.

Abstract: We have studied the optoelectronic properties of nanostructure-DNA complexes chemically assembled on transparent, semi-rigid substrates such as poly-methyl methacrylate (PMMA). DNA can be immobilized on these substrates by chemically modifying the PMMA substrates and using suitable cross-linking agents. Additionally, DNA strands end-terminated with TiO2 nanoparticles are used in this study to observe DNA cleavage through photo-induced charge carriers from the TiO2 trapped in guanine (G-) rich sites; polaron transport in such a DNA molecule is analyzed theoretically (3) to provide an understanding of charge injection into DNA as well as theformation, transport of polarons in DNA. Subsequent AFM measurements are used to study the structural characteristics of DNA on the PMMA substrates. Raman spectral lines observed in the 750-850 cm-1 region may be attributed to the phosphodiester backbone in the DNA. The fabrication of these nanostructure-DNA ensembles wil l be discussed and their Raman and AFMcharacterization will be presented.

Abstract: Clean water supply is critical for public health and food production. Currently, about 2.7 billion people around the world lack access to clean water for daily activities. Inadequate sanitation and resulting water-borne diseases lead to millions of deaths every year. While centralized wastewater treatment facilities are not practical in many parts of the developing world, small-scale decentralized treatment represents an attractive alternative that can provide necessary water treatment for reuse. Among various techniques, electrochemical oxidation (EO) has been demonstrated to be particularly suitable for the purpose of decentralized onsite treatment. Performance of EO process depends greatly on the in-situ generation of reactive species, which is determined by the nature of anode materials. Desirable anodes should be efficient in generating reactive species and inert in producing oxygen (O 2 ). Common electrodes possessing these features, such as boron-doped diamond (BDD), antimony-doped tin oxide (Sb-SnO 2 ), and lead oxide (PbO 2 ), have been studied extensively. Among them, Sb-SnO 2 is most applicable for onsite treatment purpose since it has lower manufacture cost comparing to BDD and less toxic byproduct generation comparing to PbO 2 . A modification of Sb-SnO 2 by adding nickel as an additional dopant (Ni-Sb-SnO 2 ) has been reported for its ozone generation capacity, which is desirable since O 3 represents a powerful and more environmentally-friendly oxidant comparing to free chlorine due to cleaner transformation byproducts. While many studies have tried to examine these two types of coatings separately and possible mechanisms for ozone generation have been proposed, none had studied the changes in reactive species generation or reaction kinetics in various electrolytes when ozone is present in an electrochemical system. In this study, a new double-layer anode (NAT/AT) that consists of Sb-SnO 2 bottom layer (AT) coated on a titanium plate and Ni-Sb-SnO 2 top layer (NAT) was designed and prepared. The Sb-SnO2 bottom layer is expected to act as ohmic contact to enhance electron transfer from the top layer to the titanium base, while O 3 generation can be achieved by Ni-Sb-SnO 2 top layer. Moreover, having Ni-Sb-SnO 2 as the top layer offers the advantage in keeping the amount of Ni and Sb low to control leaching. The double-layer NAT/AT was characterized and its performance in reactive species (free chlorine, ozone, hydroxy radicals) was tested against the respective single-layer AT and NAT electrodes. Kinetic modeling was invoked to elucidate the mechanisms behind reactive species generation and quantify contributions to target compound removal from each species. To evaluate its applicability in actual treatment, NAT/AT was further tested in treating real latrine wastewater, during which removal of emerging organic contaminants and pathogens was monitored. Significant O 3 production was detected at NAT/AT and NAT electrodes, confirming the role of nickel in O 3 generation. Meanwhile, addition of nickel leads to lower chlorine evolution activity at NAT/AT and NAT comparing to AT, which likely results from a shift of reactive species. Generation of hydroxyl radicals (HO) was inspected using benzoic acid (BA) as a probe compound. Significant degradation of 1 mM BA in 30 mM NaClO 4 was observed with all AT, NAT/AT, and NAT electrodes within 60-90 min electrolysis. Among the three, NAT/AT has the highest BA removal rate (NAT/AT 〉 NAT 〉 AT), which could be explained by transformation of aqueous O 3 to HO as well as higher contribution from direct electron transfer. When chloride is present (NaCl electrolyte used), we found that O 3 generation was reduced since adsorbed chloride on the active sites could inhibit the recombination of adsorbed oxygen to give O 3 . With chloride, BA degradation was also slower due to the homogeneous consumption of HO by Cl - and electrogenerated free chlorine species. The results suggest that, unlike many commercially available anodes, addition of chloride is not required for electrochemical treatment processes using NAT/AT. For the above processes, rates for reactive species (O 3 , HO, Cl, Cl 2 ) generation were estimated by fitting the kinetic model to experimental data. Target compound degradation in various scenarios could be successfully precited by the model. In treating real human wastewater. Rapid COD removal was observed (around or below 100 mg/L) within 75 min, a lot shorter timescale comparing to commercially available electrodes. Significant removal of all spiked pharmaceutical compounds (~80%) was achieved in the same time period. In our study, ozone chemistry at the microenvironment of electrode/electrolyte interface was investigated and important mechanistic insights were revealed. The double-layer designed NAT/AT anode has demonstrated high reactivity for O 3 and HO generation as well as capability in wastewater treatment. While further testing and optimization are required, NAT/AT possesses great potential for application in decentralized wastewater treatment. Figure 1