ECS Meeting Abstracts最新文献

{"title":"Unraveling Spatial Charge Density Distributions at Electrode-Electrolyte Interfaces","authors":"Lalith Krishna Samanth Bonagiri, Kaustubh S. Panse, Shan Zhou, Haiyi Wu, Narayana R. Aluru, Yingjie Zhang","doi":"10.1149/ma2023-01442384mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01442384mtgabs","url":null,"abstract":"Charge distributions at electrode-electrolyte interfaces play a crucial role in many electrochemical processes, some of which are electrocatalysis, supercapacitors, batteries etc., However, most experimental techniques, either microscopy or spectroscopy tools that are used to probe these systems, cannot provide any information about the interfacial spatial charge distribution. Techniques based on kelvin-probe force microscopy (KPFM) can provide some information, however they have a very limited depth of resolution and can only work with extremely dilute electrolytes. Recently, we developed a technique known as charge profiling three-dimensional (3D) atomic force microscopy (CP-3D-AFM) which could map out the charge densities at angstrom-depth resolution. The method is based on measuring 3D-AFM maps at different electrode potentials and further using electrostatic calculations to obtain the charge density depth profiles at the respective potentials. We used this method to measure charge distributions in highly ionic electrolyte systems and can explain their differential capacitance profiles. This CP-3D-AFM technique could enable to obtain molecular structural insights for a wide range of electrolyte systems and serve in designing principles for engineering effective electrode-electrolyte interfaces.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradation and Multi-Time-Scale State Estimation of Li-Ion Batteries in Satellites","authors":"Linda Bolay, Eiji Hosono, Yoshitsugu Sone, Arnulf Latz, Birger Horstmann","doi":"10.1149/ma2023-01452465mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01452465mtgabs","url":null,"abstract":"In-orbit satellite REIMEI, developed by the Japan Aerospace Exploration Agency (JAXA), has been relying on off-the-shelf Li-ion batteries since its launch in 2005 [1]. The performance and durability of Li-ion batteries is impacted by various degradation mechanisms, one of which is the growth of the solid-electrolyte interphase (SEI). Long-term SEI growth is the greatest contributor to capacity fade in lithium-ion batteries. In this contribution, we will address several aspects of the modeling and simulation of the batteries of satellite REIMEI. We simulate long-term degradation under the generic LEO satellite cycling conditions in a P2D framework. The simulations are validated with experiments and in-flight data provided by JAXA [1]. Our group has developed models for long-term SEI growth [2,3]. To show the inhomogeneous growth of the SEI in 3D, we perform microstructure-resolved simulations [4]. These studies are the foundation for analyzing the states of the batteries, which cannot be measured in operando. To estimate the state of charge and state of health, we make use of filter techniques and the in-flight data of the satellite batteries. Kalman filters are particularly suitable for the noisy data. Since the states change on different timescales, a multi-time-scale algorithm is applied, where two filters are combined. With this approach, we aim to reliably predict the lifetime of satellite batteries in orbit. References [1] M. Uno, et al. , J. Power Sources , 196(20) (2011) 8755–8763. [2] F. Single, et al. , ChemSusChem , 11(12) (2018) 1950–1955. [3] L. von Kolzenberg, et al. , ChemSusChem , 13(15) (2020) 3901–3910. [4] L. Bolay, et al. , J. Power Sources Advances , 14 (2022) 100083.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"(Invited) In Situ Spectroscopy of Electrocatalytic and Photocatalytic Interfaces","authors":"Stephen B. Cronin","doi":"10.1149/ma2023-01462505mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01462505mtgabs","url":null,"abstract":"We report various aspects of electrochemistry and photoelectrochemistry using in situ spectroscopy of electrode (metal) and photoelectrode (semiconductor) interfaces in situ under electrochemical working conditions. These spectroscopies include sum frequency generation (SFG), transient reflectance/absorption spectroscopy (TAS/TRS), and surface enhanced Raman spectroscopy (SERS). Using surface enhanced Raman scattering (SERS) spectroscopy, we monitor local electric fields using Stark-shifts of nitrile-functionalized silicon photoelectrodes. 6 Using Graphene-enhanced Raman spectroscopy (GERS)-based Stark-shifts, we measure local electric fields and local charge densities at monolayer graphene electrode surfaces. 1 We also measured the stacking dependence and Resonant interlayer excitation of monolayer WSe 2 /MoSe 2 heterostructures for photocatalytic energy conversion. 2 Using sum frequency generation (SFG) spectroscopy, we measure the voltage dependence of the orientation of D 2 O molecules at a graphene electrode surface, which is related back to the “stiffness of the ensemble”. 3 In particular, we measured the “free OD” feature in the spectra, which corresponds to the topmost water molecule that is rotated up out of the bulk water solution and is, therefore, not hydrogen bonded. Using transient absorption spectroscopy (TAS), we measure the lifetime of hot electrons photoexcited in plasmon resonant nanostructures. 5 Using transient reflectance spectroscopy (TRS), we measure the photoexcited carrier dynamics in a GaP/TiO 2 photoelectrode, as well as the electrostatic field dynamics at this semiconductor-liquid interfaces in situ under various electrochemical potentials. 4 Here, the electrostatic fields at the surface of the semiconductor are measured via Franz−Keldysh oscillations (FKO). These spectra reveal that the nanoscale TiO 2 protection layer enhances the built-in field and charge separation performance of GaP photoelectrodes. Shi, H.T., B.F. Zhao, J. Ma, M.J. Bronson, Z. Cai, J.H. Chen, Y. Wang, M. Cronin, L. Jensen and S.B. Cronin, Measuring Local Electric Fields and Local Charge Densities at Electrode Surfaces Using Graphene-Enhanced Raman Spectroscopy (GERS)-Based Stark-Shifts. ACS Applied Materials & Interfaces, 11 , 36252-36258 (2019). Chen, J., C.S. Bailey, D. Cui, Y. Wang, B. Wang, H. Shi, Z. Cai, E. Pop, C. Zhou and S.B. Cronin, Stacking Independence and Resonant Interlayer Excitation of Monolayer WSe2/MoSe2 Heterostructures for Photocatalytic Energy Conversion. ACS Applied Nano Materials, DOI:10.1021/acsanm.9b01898 (2020). Montenegro, A., C. Dutta, M. Mammetkuliev, H.T. Shi, B.Y. Hou, D. Bhattacharyya, B.F. Zhao, S.B. Cronin and A.V. Benderskii, Asymmetric response of interfacial water to applied electric fields. Nature, 594 , 62 (2021). Xu, Z.H., B.Y. Hou, F.Y. Zhao, Z. Cai, H.T. Shi, Y.W. Liu, C.L. Hill, D.G. Musaev, M. Mecklenburg, S.B. Cronin and T.Q. Lian, Nanoscale TiO 2 Protection Layer Enhances the Built-In Field and C","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Bifunctional Oxygen Catalyst Layer Composition on Unitized Regenerative Fuel Cell Performance","authors":"Christopher P. Rhodes, Jose Fernando Godinez Salomon, Michael E. Urena","doi":"10.1149/ma2023-01362118mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01362118mtgabs","url":null,"abstract":"Proton exchange membrane unitized regenerative fuel cells (PEM-URFCs) can generate storable fuel (hydrogen) and oxidant (oxygen) which can then be used to produce power from the same cell. Combining electrolysis and fuel cell modes within the same cell allows PEM-URFCs to have the potential for lower mass, volume, and cost compared with discrete fuel cell and electrolyzer systems. The bifunctional oxygen catalyst layer (BOCL) catalyzes the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) at the same electrode, and there are wide potential differences and opposing mass transport phenomena involved within the BOCL when operating in electrolyzer or fuel cell mode. The BOCL composition, structure and morphology significantly affect performance and stability of PEM-URFCs. In our prior work, we showed bimetallic nanoframes provide bifunctional oxygen electrocatalysts with significantly higher activity compared with monometallic structures, evaluated using a rotating disk electrode configuration. 1 We will present our investigation of the effects of the BOCL composition, structure and morphology on URFC membrane electrode assemblies (MEAs) prepared using ultrasonic spraying. Catalyst composition and loading were determined to influence URFC performance, and there are tradeoffs between fuel cell performance, electrolyzer performance, and catalyst cost. In addition to the effects of the active catalyst (either Pt for ORR or IrO 2 for OER), our work supports the non-catalytically active component influences MEA performance, which is in agreement with our finding of synergistic effects of Pt and IrO 2 within rotating disk electrode measurements. 1 We are also evaluating the effects of porous transport layers and different operating conditions on URFC MEA performance and durability over repeated cycling. References Godínez-Salomón, F.; Albiter, L.; Mendoza-Cruz, R.; Rhodes, C.P. Bimetallic Two-dimensional Nanoframes: High Activity Acidic Bifunctional Oxygen Reduction and Evolution Electrocatalysts. ACS Appl. Energy Mater. 2020, 3 , 2404-2421 .","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"162 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Techno-Economic Analysis of Electrochemical Refineries Using Solid Oxide Cells for Oxidative Coupling of Methane","authors":"Fabian Rosner, Mike C Tucker, Boxun Hu, Hanna Breunig","doi":"10.1149/ma2023-0154322mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-0154322mtgabs","url":null,"abstract":"With the shift away from fossil resources, there is a need for alternative pathways to carbon-based commodities such as ethylene. The electrochemical oxidative coupling of methane (OCM) enables the synthesis of higher hydrocarbons from simple organic molecules i.e., methane and has the potential to replace conventional ethylene production in the future. However, current solid oxide OCM cell development is still in an early stage and more comprehensive system-level analyses are needed to better understand operating conditions and economics to guide research and development. For this purpose, process models and new integration strategies for the electrochemical OCM process were developed. The integration of the electrochemical OCM unit into the plant revealed to be challenging based on current solid oxide cell designs and will be discussed as part of this presentation. The performance of the OCM plant is benchmarked against current state-of-the-art ethane steam cracker plants. In this context, key performance metrics are efficiency, direct and indirect carbon dioxide emissions, power consumption, plant cost and cost of ethylene. Of particular interest are aspects of hydrogen co-production and carbon dioxide utilization as well as the impact of carbon dioxide emission factors from the grid, which have shown to be of particular importance for electrochemical processes. Moreover, critical aspects of heat integration will be discussed including fuel pre-heating, carbon deposition and thermal cell management. The analysis will provide new insights into economic cost driving factors and the impact of cell cost, current density, overpotentials and Faraday efficiency upon the cost of ethylene. Based upon this information, performance targets will be recommended that will allow electrochemical OCM to become economically competitive in a free market environment.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Boron Doped Diamond Corrosion Free Supports to Evaluate Fuel Cell Electrocatalyst Stability Under Accelerated Stress Testing","authors":"Daniel Houghton, Pei Zhao, Yisong Han, Richard Beanland, Julie V. Macpherson, Louis Godeffroy, Viacheslav Shkirskiy, Frederic Kanoufi, Jonathan Sharman","doi":"10.1149/ma2023-01382232mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01382232mtgabs","url":null,"abstract":"Proton exchange membrane fuel cell (PEMFC) electrocatalysts are typically Pt or Pt alloy nanoparticles (NPs) supported on high surface area carbon black powders, the latter which contain a significant sp 2 carbon component. One of the barriers to PEMFC commercialisation is the lifetime of the catalyst-support system, which should be at least 5,000 hours for automotive applications. [1] During the start-up and shut-down of the PEMFC, the cathode is subjected to significant oxidative potentials (greater than 1 V vs RHE) which can lead to corrosion of the predominantly sp2 bonded carbon support, a key factor which can limit the lifetime of PEMFCs. [2] High quality boron doped diamond (BDD) is an sp 3 bonded network with above 1:1000 B:C ratio, which is required for metal-like electronic conductivity. BDD has many favourable properties for electrochemical experiments, most notably: higher electrochemical corrosion resistance with respect to sp 2 carbons, low background currents, and a wide aqueous solvent window. [3] In this work we first explore the electrochemical corrosion stability of BDD when undergoing electrochemical cycling in acid solutions. To achieve this BDD substrates (BDD TEM grid) suitable for both electrochemical experiments and high magnification (single atom resolution) transmission electron microscopy (TEM) experiments were produced using precision ion polishing (Gatan PIPS-II). The surface was characterised using X-ray photoelectron spectroscopy to ensure the polishing process did not significantly alter the diamond substrate. Under aggressive electrochemical potential cycling in perchloric acid and sulfuric acid solutions, both TEM morphological analysis and Electron Energy Loss Spectroscopy (EELS) thickness measurements showed no evidence of BDD corrosion. [4] The BDD-TEM substrate was then used as a platform for investigating the degradation of a PEMFC electrocatalyst (Pt NPs) under accelerated stress testing (AST) [1] conditions on an atomic level, using the corrosion free carbon support. This enables the influence of other degradation pathways [2] (such as aggregation, Ostwald Ripening & direct dissolution) to be explored in more detail, free from issues associated with corrosion of the support. Pt NPs, in the size range 1 – 4 nm, were sputter coated onto the BDD TEM grid. Identical location ex-situ TEM (IL-TEM) [5] in combination with image analysis was used to probe NP changes e.g. size, shape, position, on an individual basis before, and after, AST (Fig. 1, which contains c.a. 200 NPs for analysis). Such measurements were complemented by Inductively Coupled Plasma – Optical Emission Spectroscopy analysis for any dissolved Pt, and electrochemical cyclic voltammetry measurements of the Pt to highlight changes in electrocatalytic behaviour (hydrogen evolution reaction and oxygen reduction reaction) due to AST cycling. Figure 1 – High magnification annular dark field (ADF) identical location images of Pt NPs, a) Pt/BDD bef","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"(Invited) Solid State Hybrid Inorganic Organic Polymer Electrolytes for Advanced Sodium Secondary Batteries","authors":"Gioele Pagot, Federico Brombin, Keti Vezzu, Enrico Negro, Vito Di Noto","doi":"10.1149/ma2023-01492563mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01492563mtgabs","url":null,"abstract":"The large-scale rollout of electric vehicles, smart grids and portable electronics is expected to require an amount of energy storage devices that the Li-ion technology alone will not be able to satisfy. In this concern, a quest for novel electrochemical energy storage technologies has started [1]. Sodium secondary batteries appear to be a good choice due to: (i) the high availability of raw materials; (ii) the low cost of sodium; (iii) the low sodium standard reduction potential; and (iv) the similarity between the chemistries of sodium and lithium, which facilitates the transition between the two technologies. Up to date, the best-performing electrolytes for the reversible deposition of sodium are based on organic solvents, which suffer from safety concerns and a poor stability towards sodium metal. Thus, research activities in this field are devoted to the development of safe and stable solid state electrolytes able to efficiently transport Na + ions. Inspired by the pioneering work done by Di Noto and co-workers [2-4], herein we present a family of hybrid inorganic-organic polymer electrolytes (HIOPEs) for advanced solid state sodium secondary batteries. The initial HIOPE is obtained by means of a reaction between zirconium ethoxide and polyethylene glycol (PEG400). The resulting material is doped with sodium perchlorate as source of Na + ions. In this system a 3D network is obtained, where inorganic zirconium metal nodes are interconnected by means of organic PEO chains. The latter ensure flexibility to the overall structure. Na + ions are coordinated by and exchanged between the oxygen atoms of the ethereal functionalities of PEO chains. In addition, to guarantee a good structural stability, positively charged Zr nodes partially coordinate perchlorate anions, thus raising the sodium transference number. After doping with the poly(ethylene glycol) dimethyl ether (PEGDME250) plasticizer, a room temperature conductivity higher than 10 -4 S cm -1 is demonstrated. An advanced study of the thermal and structural properties of the proposed materials is presented, with a particular focus on the interactions established between the different chemical species and complexes composing the HIOPEs. The conduction mechanism is elucidated starting from the results obtained in a wide range of temperatures from broadband electrical spectroscopy studies. Taking all together, this study offers insights on the application of non-traditional solid state electrochemical functional components as replacements for conventional solvents in the emerging field of sodium secondary batteries. Acknowledgments The project “Interplay between structure, properties, relaxations and conductivity mechanism in new electrolytes for secondary Magnesium batteries” (Grant Agreement W911NF-21-1-0347-(78622-CH-INT)) of the U.S. Army Research Office. The project “ACHILLES” (prot. BIRD219831) of the University of Padua. The project “VIDICAT” (Grant Agreement 829145) of the FET-Open call","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Capture and Electrochemical Conversion of CO₂ into Carbon Nanotubes Using Molten Alkali Metal Borates","authors":"Michael Philip Nitzsche, Lev Bromberg, T. Alan Hatton","doi":"10.1149/ma2023-01492558mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01492558mtgabs","url":null,"abstract":"Molten alkali metal borates have recently shown promise as high-temperature sorbents for capture of CO 2 and acid gases. These molten salt sorbents enable realization of thermodynamic enhancements offered by conventional solid high temperature sorbents while resolving practical challenges such as morphological degradation. Prior studies have focused on regeneration of alkali borates through steam sweeping and thermal cycling. In this work, we demonstrate that mixed sodium-lithium borate salts as CO 2 sorbents can also be regenerated electrochemically, producing valuable multiwalled carbon nanotubes (MWCNT) via electroreduction of captured CO 2 . Effects of cathode materials and operating conditions in CO 2 electroreduction in molten sodium-lithium borate are quantified. By varying relative starting compositions of alkali borates and alkali carbonates, an optimal composition of borates and carbonates is determined, achieving high coulombic efficiencies and significantly higher CO 2 uptake capacities than traditionally employed carbonate salts used for conversion of CO 2 into CNTs in the desirable 550-650°C range.","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of Photoelectrochemical Signal Transduction with RNA-Cleaving Dnazymes for Culture-Free Detection of Bacteria","authors":"Sadman Sakib, Zijie Zhang, Enas Osman, Farhaan Kanji, Fatemeh Bahkshandeh, Yingfu Li, Igor Zhitomirsky, Leyla Soleymani","doi":"10.1149/ma2023-01532635mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01532635mtgabs","url":null,"abstract":"There is a growing interest in developing ultrasensitive biological sensors that can be used for rapid testing at the point-of-need. 1 A major hurdle in developing such sensors for detecting pathogens such as bacteria is that they require target enrichment or amplification to deliver the required limit-of-detection. 2 Among signal transduction strategies, photoelectrochemical (PEC) signal readout, built on the use of light for enhancing electrochemical reactions, is emerging as an ultrasensitive signal transduction mechanism. 3 However, the existing PEC platforms fail to deliver single step testing due to the existence of multiple manual steps, including the addition of biological materials labelled with inorganic photoactive nanoparticles, for signal transduction. 3 RNA-cleaving DNAzymes (RCDs), a class of synthetic nucleic acids, have been selected for precisely identifying specific bacterial species without the need for sample processing. 4 RCDs are molecular switches that cleave a segment of themselves in response to a particular bacterial target, combining biological recognition with signal transduction. 4 We developed photoactive RCDs by tagging them with TiO 2 nanomaterials for combining these molecular switches with PEC signal readout. We designed these molecular switches to make and then break semiconductive heterostructures in response to bacterial targets. These photoactive RCDs were the foundational basis for the design novel and highly sensitive PEC bacterial sensor. We developed two photoactive materials for use in the PEC bacterial assay: TiO 2 nanorod clusters (rutile) that form high surface area photoelectrodes and sub-nanometer sized TiO 2 -nanoparticles (anatase) that link to RCDs to create photoactive reporter probes. Combining TiO 2 -assemblies and TiO 2 -nanoparticles gives rise to a semiconductor heterostructure that massively improves the photoexcitation efficiency of the combined material system and improves photocurrent generation. Our PEC bacterial sensor makes use of this phenomenon for bacterial detection by utilizing photoactive RCDs to modulate photocurrent by breaking and then rebuilding the TiO 2 heterostructures, as a signaling mechanism. The assay consists of a release electrode – modified with photoactive RCDs and a capture electrode – modified with single-stranded DNA probes. Upon target interaction, RCDs release photoactive reporters which are captured by the probes, decreasing the release electrode signal while raising the capture electrode signal. The resulting biosensor can detect E. coli bacterial contamination with high specificity and has achieved a very low limit of detection of 21 CFU/mL in buffer and 18 CFU/mL in lake water samples. These results have set a new record for amplification-free detection of bacteria, that does not rely on target enrichment, reagent addition, or sample processing. This presents a new tool for rapid and in-field water testing. References Nat. Microbiol. , 1 , 16089 (2016).","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting Oxygen Release and Surface Reconstructions in Li-Ion Battery Cathodes Via Automated Construction of Computational Surface Phase Diagrams and Machine Learning","authors":"Xinhao Li, Wing-Chi Ashley Lam, In Won Yeu, Abhiroop Mishra, Joaquin Rodriguez Lopez, Alexander Urban","doi":"10.1149/ma2023-01452470mtgabs","DOIUrl":"https://doi.org/10.1149/ma2023-01452470mtgabs","url":null,"abstract":"Although LiNiO 2 (LNO) is chemically very similar to LiCoO 2 (LCO), LNO and related Co-free Ni-rich cathodes suffer from continuing surface degradation via oxygen gas release during electrochemical cycling that leads to the formation of surface phases with high impedance. While the surface degradation of LNO and related cathode compositions have been characterized experimentally on a phenomenological level, an understanding of the surface reconstructions that form on the atomic scale and the intrinsic surface instability of LNO compared with other related cathode compositions is still lacking. To shed light on surface reactivity, we developed a thermodynamic methodology for the prediction of voltage and temperature-dependent surface electrode reconstructions [1] and a computational framework to automate the time-consuming enumeration of surface reconstructions, the construction of symmetric surface-slab models, and the analysis of surface phase diagrams [2]. By applying first-principles atomistic modeling, we determined the self-reduction mechanism of LNO and compared the stable surface reconstructions with those of LCO. To further assess the surface stability of more complicated NMC/NCA cathodes with the help of our own generated LNO and LCO databases, we developed a supervised machine learning (ML) model to train on geometrical and electronic fingerprints from surface and bulk models, respectively. Our results provide insight into the initial stages of surface degradation in Ni-rich cathodes and lay the foundation for the computational design of stable cathode materials against oxygen release. Li, X.; Wang, Q.; Guo, H.; Artrith, N.; Urban, A. ACS Appl. Energy Mater. 2022, 5 (5), 5730–5741. Li, X.; Qu, J.; Yeu, I.; Li, Z.; Rodríguez-López, J.; Urban, A., in preparation , 2023","PeriodicalId":11461,"journal":{"name":"ECS Meeting Abstracts","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135089256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}