Bulletin of the American Physical Society
APS March Meeting 2023
Volume 68, Number 3
Las Vegas, Nevada (March 5-10)
Virtual (March 20-22); Time Zone: Pacific Time
Session Z17: Nanoscale Chemical Physics and Other Frontiers |
Hide Abstracts |
Sponsoring Units: DCP Chair: SABYASACHI Roy Chowdhury, University of South Dakota Room: Room 209 |
Friday, March 10, 2023 11:30AM - 11:42AM |
Z17.00001: Optical phase control induced by molecular vibrations in strongly driven infrared nanoresonators Mauricio A Arias, Felipe F Herrera, Johan F Triana Recent experimental advances on quantum control with mid-IR nanoresonators have stimulated the development of quantum theory that can accurately describe driven-dissipative light-matter physics in the quantum few-photon regime. We propose a semi-empirical quantum optics approach to describe light-matter interaction between nanoconfined resonant fields with ensembles of molecular vibrations in the mid-IR, subject to ultrafast laser driving with femtosecond pulses. For strong pulses that moderately deplete the vacuum field level, the model predicts the ability to implement coherent intensity-dependent phase shifts on the scattered output pulse at room temperature, which rely on a dynamical blockade effect that occurs naturally for weak light-matter coupling due to the anharmonicity of the vibrational potential [1]. The scaling of the proposed phase shifts with molecule number is also discussed. Our results suggest novel applications of vibration-nanoantenna systems for quantum control and quantum information processing in the mid-infrared regime. |
Friday, March 10, 2023 11:42AM - 11:54AM |
Z17.00002: Electrosorption-Induced Actuation in Nanoporous Silicon Manuel Brinker, Patrick Huber Porous silicon provides a scaffold structure to study the confinement related effects of soft matter. |
Friday, March 10, 2023 11:54AM - 12:06PM |
Z17.00003: Exploring IRMOF-1 as chemical sensors based in optics Rubén A Fritz, Felipe Herrera Monitoring and detecting chemical compounds of interest requires portable, reusable, and non-destructive chemical sensors with high specificity. As a porous material, metal-organic frameworks (MOFs) are potentially useful for optical sensing; upon loading, their optical properties, including dielectric function change, and such phenomena can be exploited for sensing purposes. A wide range of sciences has benefited from metal-organic frameworks because of their exceptional crystalline properties and applications. MOFs are formed by molecules used as linkers and metals as nodes in a modular fashion. This creates a network that, in some cases, can form pores that can adsorb other chemicals. The combinatorial ensemble of structures from their constituent parts yields an infinite amount of possible combinations. This creates a very rich chemical space that is extremely challenging to explore solely by experiment. Here we present a computational approach to study the changes in the optical properties of the IRMOF-1 upon loading methane. Our work aims to establish the basis for a computational filter and characterization of MOFs for chemical sensing. |
Friday, March 10, 2023 12:06PM - 12:18PM |
Z17.00004: Aptasensors based on graphene field-effect transistors for arsenite detection Zhaoli Gao All-electronic chemical sensors based on field-effect transistors (FETs) hold tremendous promise for rapid and sensitive detection of arsenic in groundwater. Their sensitivity, however, is fundamentally limited by a chemical gating mechanism where target ion charges are directly measured. We have developed a highly sensitive aptasensor, based on scalable graphene FETs, which relies on the conformational change of the negatively charged aptamer upon arsenite binding, offering a wide analytical range, from 0.05 to 1000 ppb, and with a 0.02 ppb detection limit. Circular dichroism spectroscopy studies confirmed the conformational change of the aptamer, and molecular dynamic studies further validated that arsenite had bound with the hairpin loop of the aptamer. This work provides a highly accurate chemical sensing platform for rapid detection of arsenic in drinking water. |
Friday, March 10, 2023 12:18PM - 12:30PM |
Z17.00005: Investigation of the direct methane oxidation over Sm-doped ceria for application in SOFC system Hyunwoo Ha, Graeme Henkelman, Yoonseok Choi, Hyun You Kim, WooChul Jung One of the key advantages of solid oxide fuel cells is that they can use hydrocarbon fuels, and CeO2-δ (ceria)-based oxides play an important role in hydrocarbon activation and carbon coking inhibition. However, even for the simplest hydrocarbon molecule, CH4, the mechanism of electrochemical oxidation on the ceria surface remains largely unknown. This is due to the complex architecture of typical metal/oxide composite electrodes and the heterogeneity of electrode reactions involving multiple chemical/electrochemical steps. Here, we present a Sm-doped ceria thin-film model electrochemical cell capable of selectively monitoring CH4 direct-oxidation on the ceria surface. Combined impedance spectroscopy, in operando X-ray photoelectron spectroscopy and DFT calculations reveal that the ceria surface catalyzes the C-H cleavage and that the overall electrode reaction rate is dominantly determined by the H2O formation step. These observations end the longstanding academic debate over the direct use of CH4 and provide an ideal electrode design for high-performance fuel cells. |
Friday, March 10, 2023 12:30PM - 12:42PM |
Z17.00006: Interface Engineering Between Ag Nanocatalyst and CuxO Support for the Fuel Cell Application Kihyun Shin, Changsoo Lee An iterative electrochemical activation process is demonstrated to maximize the interface between Ag and CuxO. Morphological reconstruction and phase transformation of CuxO occurs through the iterative electrochemical redox reaction, as indicated by energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. The activated Ag/CuxO/C catalysts exhibits enhanced oxygen reduction reaction performance, with an onset potential of 0.86 V vs. the reversible hydrogen electrode, a Tafel slope of 46 mV dec−1, and a high stability as compared to Ag/C. A mechanistic study using density functional theory shows that the weakened binding energy of the OH intermediate, originating from the charge transfer from Ag to CuxO, improves the ORR activity at the interface sites of the Ag/CuxO electrocatalysts. Ag/CuxO shows a higher limiting potential of 0.14 V for interface sites than isolated Ag nanoparticles. The interfacial charge transfer between Ag and CuO is verified experimentally. |
Friday, March 10, 2023 12:42PM - 12:54PM |
Z17.00007: Modifying the cooperative effect of composites [Fe(Htrz)2(trz)](BF4) plus polyaniline through the addition of iron magnetite nanoparticles Wai Kiat Chin The high spin state to low spin state transition characteristics of the spin crossover molecule [Fe(Htrz)2(trz)](BF4) (where Htrz = 1H-1,2,4-triazole) plus polyaniline can be modified by the addition of iron magnetite (Fe3O4) nanoparticles. [Fe(Htrz)2(trz)](BF4) exhibits a strong spin state transition from a diamagnet (S=0) to moment paramagnet (S=4) with increasing temperature, but this spin state transition is hysteretic in temperature due to intermolecular interactions - otherwise known as cooperative effects. The temperature dependent hysteresis of the spin state transition decreases, in [Fe(Htrz)2(trz)](BF4) polymer thin films, with the addition of polyaniline. This indicates a decrease in the cooperativity in [Fe(Htrz)2(trz)](BF4) polymer. Addition of the ferromagnetic Fe3O4 nanoparticles leads to a strong superparamagnetic contribution and an increase in the temperature dependent hysteresis of the spin state transition. This suggests that there is not just intermolecular interactions due to strain and steric effects, but also exchange coupling. |
Friday, March 10, 2023 12:54PM - 1:06PM |
Z17.00008: Microscopic Theory, Analysis, and Interpretation of Conductance Histograms in Molecular Junctions Ignacio Franco, Pilar Cossio, Leopoldo Mejia Molecular junctions have emerged as a powerful tool to investigate chemistry and physics at the single-molecule limit. However, their utility as a platform to develop spectroscopies and construct molecular devices is limited by the broad conductance histogram typically encountered in experiments. Here we advance a microscopic theory of the conductance histogram by merging the theory of force spectroscopy developed in biophysics with molecular conductance. The theory augments the information content that can be extracted from molecular junction experiments and identifies the key physical elements that need to be controlled to enhance the ability of this class of experiments to resolve molecular events. |
Friday, March 10, 2023 1:06PM - 1:18PM |
Z17.00009: Reaction-driven restructuring of Pt-Rh nanoparticles: Bragg coherent diffraction imaging (BCDI) during gas-surface reactions Tomoya Kawaguchi, Thomas F Keller, Henning Runge, Luca Gelisio, Christoph Seitz, Young Y Kim, Wonsuk Cha, Stephan O Hruszkewycz, Ross J Harder, Ivan A Vartanyants, Andreas Stierle, Hoydoo You Platinum group metals and their metal alloys are among the most important catalysts for organic and electrochemical reactions [1,2]. For this reason, the structure-activity relationships of the platinum alloy nanoparticles have been a focus of extensive studies. Some studies [3,4] even suggested that the core-shell compositions of nanoparticles can dynamically change depending on gas reaction environments. Until now, however, there was no direct evidence for the dynamic restructures because there has been no in-situ experimental technique that can directly image the internal alloy compositions. The situation changed recently because new coherent X-ray imaging techniques emerged and advanced rapidly. The internal composition of Pt-Rh nanoparticles was, therefore, analyzed in situ under different gas environments, which unveiled dynamic composition changes near the particle surfaces [5]. |
Friday, March 10, 2023 1:18PM - 1:30PM |
Z17.00010: Atomistic simulations of double layer graphene structure and its reactivity Malgorzata Kowalik, Nadire Nayir, Saiphaneendra Bachu, Swarit Dwivedi, Nasim Alem, Adri C Van Duin The two-dimensional transition metal dichalcogenides (TMDs), such as WSe2, are considered for a range of optoelectronic or energy applications. However, the structural differences in the graphene templet may strongly affect the TMD growth. To explain experimentally observed stacking-dependence of WSe2 nucleation, we performed the ReaxFF reactive molecular dynamics simulations to 1) identify the possible stacking changes in the case of the Bernal stacked as well as twisted bilayer graphene due to an in-build strain difference between the graphene layers, and 2) assess the possible changes in reactivity of the resultant stacking configurations. In the case of the Bernal stacked bilayer graphene with in-build strain difference we observed a formation of interlayer changes in stacking order (dislocations). Moreover, if this in-build strain difference is sufficiently high, we can also observed a localized buckling of graphene. This localized buckled graphene is characterized with higher reactivity, compared to any other considered stacking configuration, and might be responsible for experimentally observed higher density of WSe2 grown in the cases of Bernal stacked bilayer, compared to the twisted one. |
Friday, March 10, 2023 1:30PM - 1:42PM |
Z17.00011: Towards realistic simulations of strongly correlated open quantum systems in steady-state Anqi Li, Michael Galperin We discuss the applicability of theoretical Green's function methods to open quantum systems out of equilibrium, in particular, to single molecule junctions. Two characteristic energy scales governing the physics are many-body interactions within junctions and molecule–contacts couplings. Both weak interactions and weak coupling cases can be treated within diagrammatic expansions. However, lacking small parameter, the intermediate regime, where these two scales are comparable, can mostly be treated efficiently within the nonequilibrium dual approaches. We discuss the recently developed auxiliary quantum master equation dual-fermion and dual-boson approaches. Applications of both approaches in realistic simulations are limited by heavy numerical cost, which grows exponentially with system size when solving the auxiliary quantum master equation. Therefore, we explore the possibility of employing the flow equation renormalization group and low-order many-body Green's function techniques as inexpensive solvers capable of providing single- and two-particle Green's functions of the auxiliary problem. This will be a valuable addition to the theoretical toolbox by itself and as a part of a divide-and-conquer type of approach to study the response of strongly correlated open quantum systems to external perturbations in the field of spintronics, optoelectronics, and energy harvesting. |
Friday, March 10, 2023 1:42PM - 1:54PM |
Z17.00012: Synthesis of programmable graphene nanoribbons from perfectly sequenced polymers of molecular precursors Ziyi Wang, Peter H Jacobse, Jiangliang Yin, Daniel Pyle, Guangbin Dong, Michael F Crommie Graphene nanoribbons (GNRs), nanometer-wide strips of graphene, are interesting because of their versatile electronic, optical, and magnetic properties. Progress in bottom-up synthesis over the last decade has enabled different types of GNRs to be realized by chemically designing molecular precursors that can be linked into molecular chains (i.e., polymers) and then subjected to cyclodehydrogenation to produce GNRs with atomically-precise widths, dopants, and edge configurations. Despite this progress, there currently exists no technique for “rationally” synthesizing GNRs that exhibit engineered precursor sequences that go beyond the simplest A-B-A-B-A-B pattern and that have well-defined length. More complex sequencing is necessary to create the types of reproducible heterojunctions required for useful nanodevice functionality (e.g., designed sequences of GNR p-n junctions, metallic segments, and quantum dots). Here we describe a new method for preparing diverse GNR structures from different molecular building blocks that can be attached in any order, thus yielding the first truly “sequenced” GNRs. This method enables precise control over GNR length, shape, and sequence of internal structural elements. The technique used to accomplish this is called protecting-group-aided iterative synthesis (PAIS), and involves monomer-by-monomer construction of polymers to yield well-defined molecular sequences. GNR polymers created using PAIS were deposited onto Au(111) for subsequent cyclodehydrogenation using matrix-assisted direct (MAD) transfer, a technique that allows clean surface deposition of large molecules from solution. The resulting complete, fully sequenced GNRs were imaged using low-temperature bond-resolved scanning tunneling microscopy (BRSTM). I will show images of atomically-precise GNR heterojunctions produced using PAIS that would not be possible using other more conventional GNR synthesis techniques. PAIS opens the door to future GNRs having complex multi-heterojunction layouts designed for quantum device functionality. |
Friday, March 10, 2023 1:54PM - 2:06PM Author not Attending |
Z17.00013: Thermoplasmonic Effects of Gold Nanorods Priscilla Lopez, Kathryn Mayer, Nicolas Large Gold nanoparticles have been used in recent decades in many biomedical applications including photothermal therapies, sensing, and enhanced spectroscopies due to their unique plasmonic properties. These properties which can include enhanced electric fields and a localized photothermal heating effect, result from their localized surface plasmon resonance (LSPR). The LSPR itself is dependent on many factors including properties of the particle such as shape, size, and composition but also on the dielectric properties of the surrounding medium and the presence of neighboring particles (plasmonic interactions). In addition to utilizing directly the photothermal effect, there has been interest in the effect of that plasmonic heating on bound biomolecules that can be used for in vivo studies. With the potential development of new applications using these hybrid plasmonic systems there now arises the need for more basic knowledge on the relationship of the plasmonic heating of nanoparticles to coupled biomolecules. In this work we created a computational model of gold nanorods that can be used to predict the plasmonic and photothermal effects of various nanoparticles and nanoparticle-biomolecule conjugates including temperature profiles and rates of temperature increase. These models were compared to a photothermal heat study conducted using synthesized gold nanorods coupled to bovine and human serum albumin (BSA and HSA). Future work in this study will include examining the heating effect of the gold nanorods on the coupled proteins experimentally using analytical techniques such as Raman spectroscopy. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700