bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Photon Upconversion through Dynamic Exciton at Organic Semiconductor Interface
Authors: Izawa Seiichiro 
Published: July 2022

Energy of photons, i.e. the wavelength of light, can be upgraded through interactions with materials—a process called photon upconversion (UC). Although UC in organic solids is important for various applications, such as in photovoltaics and bioimaging, conventional UC systems, based on intersystem crossing (ISC), suffer from low efficiency. Herein, we report a novel UC mechanism at heterojunctions of organic semiconductors in bilayer structures. The UC occurs by triplet formation during the charge separation and recombination through dynamic exciton: charge transfer (CT) state at the interface. This can efficiently convert the incident photons to triplets without relying on the ISC, whose rate is typically accelerated by the heavy-atom effect. As a result, a solid-state UC system is achieved with an external efficiency of two orders of magnitude higher than those of the conventional systems. Using this result, efficient UC, from near-infrared to visible light, cab be realized on flexible organic thin films under a weak light-emitting diode-induced excitation, observable by naked eyes.
Reference: S. Izawa and M. Hiramoto, Nat. Photon., DOI: org/10.1038/s41566-021-00904-w.
Catalytic and Photocatalytic Functionality of Diprotonated Porphyrins
Authors: Kojima Takahiko 
Published: July 2022

Development of strategy in energy conversion and storage is indispensable for a sustainable society. So far, redox-active transition metal complexes have been used as efficient catalysts and photosensitizers in energy-converting reactions such as hydrogen evolution through thermal and photoinduced electron transfer (ET).
We have been working on development of redox and photochemical functionality of diprotonated saddle-distorted porphyrins based on ET reactions. Herein we would like to highlight recent advance in our study of catalytic dioxygen reduction and hydrogen evolution using diprotonated forms of dodecaphenylporphyrin (H2DPP) derivatives as organocatalysts and photosensitizers.
A diprotonated form of a water-soluble H2DPP derivative can act as a photosensitizer (PS) in photocatalytic oxidation of organic substrates in water using Na2S2O8 as an oxidant under visible-light irradiation.1 On the contrary, diprotonated H2DPP has been used as a PS in photocatalytic H2 evolution using platinum nanoparticles as catalysts under near-infrared (710 nm) irradiation in the quantum yield of 17%.2

Diprotonated H2DPP (H4DPP2+) can serve as an organo-photocatalyst in highly selective and efficient O2 reduction to afford H2O2 under photoirradiation at 480 nm; the quantum yield of H2O2 generation was 12% and turnover frequency was 500 h–1.3

Interconversion of O2 and H2O2 has been achieved using an N21,N23-dimethylated H2DPP derivative.4 The porphyrin is reduced by H2O2 to form the corresponding isophlorin derivative as a two-electron-reduced product, which is in turn oxidized by O2 to afford the porphyrin and H2O2. We also developed efficient O2 reduction using N21,N22- and N21,N23-dimethylated H2DPP derivatives as catalysts; in the catalysis, catalytic mechanisms and performance depend on the structures of catalysts used in terms of interaction between O2 and the corresponding isophlorins.5

References

T. Ishizuka et al., Green Chem.
2018, 20, 1975.

H. Kotani et al., ACS Appl. Energy Mater.
2020, 3, 3193.

E. Aoki et al., Chem. Commun.
2019, 55, 4925.

W. Suzuki et al., J. Am. Chem. Soc.
2019, 141, 5987.

W. Suzuki et al., Chem. Eur. J.
2020, 26, 10480.
Polypeptide Oligomers Comprised of Corroles – Hydrogen Bonding Provides “Short-Circuit” Coupling Pathways for Electron Transfer
Authors: Gryko Daniel T. , Orłowski Rafał , Clark John , Gray Harry B. , Vullev Valentine I. , Szumna Agnieszka 
Published: July 2022

Electron flow through proteins is a crucial factor, which decides about their multiple functions in living organisms. Incorporating polypeptides as bridges in donor-bridge-acceptor (DBA) conjugates allows for examining how various structural features in proteins affect the kinetics of the CT processes they mediate. Based on the premise that hydrogen-bonds formation could serve to modify geometry and special orientation of donor and acceptor scaffolds in covalently linked bichromophoric system we designed and synthesized series of dyads comprised of perylene-bisimide and free-base corrole. Specifically, the object of the study was hydrogen-bonded discrete assemblies of corroles possessing core-NH as hydrogen bond donor and amide groups located at position meso-10 as hydrogen bond acceptor. The three dyads differ in type and number of bridging aminoacids’ moieties: L-alanine and L-phenylalanine and one or four respectively. These complex corroles were prepared via synthesis of perylenebisimide-amino acid conjugate possessing free NH2 group followed by amidation of COOH-corrole. Combined steady-state and time-resolved photophysical studies identified that electron-transfer occurs in all four bichromophoric systems. Our focus was on alanine tetramer that is long enough not to mediate too efficiently through-bond CT. A corrole moiety serves as an electron donor, and a perylenediimide as an acceptor. The picosecond rates of electron transfer suggests that the electronic-coupling pathways cannot be through-bond and most likely involve through-hydrogen bond interaction.
References

Orłowski, R.; Vakuliuk, O.; Gullo, M. P.; Danylyuk, O.; Ventura, B.; Koszarna, B.; Tarnowska, A.; Jaworska, N.; Barbieri, A.; Gryko, D. T. Commun.
2015, 51, 8284-8287.

Orłowski, R.; Cichowicz, G.; Staszewska-Krajewska, O.; Schilf, W.; Cyrański, M. K.; Gryko, D. T. Eur. J.
2019, 25, 9658-9664.

Figure 1
Atomic-Scale Oxide Growth and Dissolution Kinetics on Ni-Cr Alloys
Authors: Xiao Penghao , Orme Christine , Wood Brandon C. 
Published: July 2022

Passivation oxide formation is the key for corrosion control of metal alloys. The kinetics of competing oxide formation and dissolution determines alloy corrosion behaviors in aqueous solution. Despite the important role of the multi-component oxide evolution, little has been known on the kinetics from the atomistic level. To this end, we have built a computational framework that enables simulations of competing kinetic processes in multi-component oxides from first principles. The effects of applied voltage, pH and temperature on oxide growth, dissolution and reprecipitation can all be captured in this model. Combining with our experimental measurements on alloy 22, we identified three voltage regimes with distinct oxide thicknesses and compositions. In the low voltage regime, oxide growth is the dominating process. The Cr/Ni ratio in the oxide is close to that in the alloy. In the medium voltage regime, Ni dissolves from the mixed oxide, NixCryO, and reprecipitates back as Ni oxide, NixO, to achieve phase separation. The resulted oxide film is significantly thickened with a duplex structure formed. In the high voltage regime, Ni dissolution dominates, and the Cr/Ni ratio increases. The temperature and pH dependencies have also been simulated. Higher temperature moves the dissolution-reprecipitation to the lower voltage; lower pH suppresses Ni reprecipitation and results in a thinner oxide film. These trends are also in agreement with the experiments.
The oxide energetics of various stoichiometries are calculated by the density functional theory (DFT). Then the obtained data are used to train a surrogate lattice Hamiltonian with the cluster expansion (CE) method. Finally, kinetic Monte Carlo (KMC) simulations are run with the cation hopping barriers calculated on-the-fly based on the local environments from the combination of the above Hamiltonian and the linear Brønsted−Evans−Polanyi (BEP) relation.
(Digital Presentation) Microbial Fuel Cells: Electrochemical Property and Long-Term Stability Improvement
Authors: Houf William , Bashir Sajid , Liu Jingbo Louise 
Published: July 2022

The microbial fuel cells (MFCs) are bioelectrochemical devices to convert chemical energy into electricity using a microorganism, without relying on abiotic catalysts and fossil fuels. The microbes enable proton production and electron transfer by oxidizing organic matters, which can be from wastewater, biomass, and other feedstocks. The electrons ﬂow will produce a direct electrical current, causing the potential diﬀerences between the anode and cathode compartments.
The aromatic sulfonation of membrane may result in acidity changes in the anode, causing microbe inhibitions. The PVA based novel membrane was developed and used as the electrolyte to overcome the above problems. The brewer’s yeast (S. cerevisiae) as a biocatalyst was used in MFCs due to the resilience to environmental changes and simple mechanism of electron transfer. The S. cerevisiae an eukaryote was found to easily retrofit into ethanol plants for in situ power generation, which were found improve the microbial fuel cell performance by our study.
This study indicated that anodic biofilm modification using nanoparticles is an effective approach to improve electrochemical activities due to their high surface area and high electronic conductivity. The red-light facilitates the efficient electron transfer through mediated redox couples within the anodic biota-anchored films. These redox mediators may represent an electronic network permeating the biofilm that can promote long-range electrical transfer in an energy-efficient manner, as a result of increasing MFC electricity production. As society migrates from consumption of gasoline to low carbon-based fuels, the MFCs becomes important to produce electrical energy with near zero net emission.

Figure 1
Poly(ethylene oxide)-Based Electrolytes for Solid-State Potassium Metal Batteries
Authors: Khudyshkina Anna D. , Morozova Polina A. , Butzelaar Andreas J. , Hoffmann Maxi , Wilhelm Manfred , Theato Patrick , Fedotov Stanislav S. , Jeschull Fabian 
Published: July 2022

Most conventional batteries today employ organic liquid electrolytes (LEs) that are not only flammable, but also serve as a medium for irreversible side reactions at the electrode interfaces, especially when metal is used as electrode. In post-lithium systems, such as potassium batteries, this issue is even more pronounced due to a higher reactivity of the metal as compared to lithium, and typically results in electrochemical instability leading to a rapid capacity fade of the battery.[1] When switching from LEs to solid polymer electrolytes (SPEs) that typically show better electrochemical stability at low (< 0.5 V vs. K+/K) and high (> 4 V vs. K+/K) potentials due to polymers inherent inertness, enhanced cycle life of the battery is expected.[2] Moreover, well-known disadvantage of SPEs in Li-based batteries, i.e., poor ionic conductivity at ambient temperature, could be overcome in systems with larger cation size, e.g. K+
[3,4], potentially removing some of the bottlenecks previously encountered in the case of Li-transport.
In this presentation, a series of poly(ethylene oxide) - potassium bis(trifluoromethane sulfonyl)imide (PEO-KTFSI) compositions with different salt concentration was investigated for their potential application as SPEs in potassium metal batteries. To identify the most promising candidate in terms of ion transport and mechanical integrity, the effect of KTFSI concentration on thermal, rheological and electrochemical properties was studied. Several electrolyte compositions were examined in solid-state potassium batteries with a potassium metal negative electrode, and a positive electrode from Prussian blue analogue family. Our results reveal the advantages of solid-state systems with respect to improved capacity retention and Coulombic efficiency as compared to the reference system with carbonate-based LE, as demonstrated in Figure 1, thus paving the way for a new generation of potassium batteries with significantly improved key performance parameters.

Figure 1. Comparison of potassium half-cells employing different electrolyte systems: carbonate-based liquid electrolyte (LE) vs. PEO-based solid polymer electrolyte (SPE) (a) capacity retention and (b) corresponding Coulombic efficiencies.
[1] H. Wang, D. Zhai, F. Kang, Energy Environ.
Sci.
2020, 13, 4583–4608.
[2] J. Mindemark, M. J. Lacey, T. Bowden, D. Brandell, Prog. Polym. Sci.
2018, 81, 114–143.
[3] M. Perrier, S. Besner, C. Paquette, A. Vallée, S. Lascaud, J. Prud’homme, Electrochim. Acta
1995, 40, 2123–2129.
[4] U. Oteo, M. Martinez-Ibañez, I. Aldalur, E. Sanchez-Diez, J. Carrasco, M. Armand, H. Zhang, ChemElectroChem
2019, 6, 1019–1022.

Figure 1
(Digital Presentation) Pinpointing the Potential-of-Zero-Charge in a Alumina-Coated Aluminum/Water Interface Model for Corrosion Applications
Authors: Leung Kevin 
Published: July 2022

The surfaces of most metals immersed in electrolytes feature a several nanometer-thick oxide/hydroxide layer in aqueous electrolytes. This leads to the existence of both a metal/oxide and an oxide/liquid electrotlyte interface. The resulting complexity, and the uncertainty about the structure of and the charges on the surface films, make it challenging to predict from first principles the potential-of-zero-charge (PZC) which has been correlated to the pitting potential [1]. In this work, we use large-scale Density Functional Theory and ab initio molecular dynamics to calculate the PZC of a Al(111)|gamma-Al(2)O(3)|water model within the context of aluminum corrosion. By partitioning the multiple, complex interfaces involved into binary components with additive contributions to the overall work function and voltage, we calculate the PZC in liquid water for this model. Simultaneously, we calculate the orbital energy levels of defects like oxygen vacancies in gamma-Al(2)O(3), which are critical parameters in theories associated with pitting corrosion onset. Our predictions align the Fermi level at PZC with oxygen vacancy impurity defect levels, and estimate the voltage needed to generate charged oxygen vacancies in the flat band approximation. The similarities and differences in results and assumptions used between our model calculations and experiments will be discussed.
[1] J.~O'M. Bockris and Y.~Kang, J. Solid Electrochem. 1:17 (1997).
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the document do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

Figure 1
Electrochemical Detection of Peroxynitrite Using Selenium-Decorated Graphene
Authors: Kalil Haitham , Ibrahim Magdy A , Curtis William , Bayachou Mekki 
Published: July 2022

Peroxynitrite and other reactive oxygen species (ROS) have shown contribution to oxidative stress-driven diseases including cardiovascular dysfunction. A precise detection of these species in biological systems is not only crucial for understanding the genesis and progression of diseases, but also for developing and evaluating effective therapies. In the past decade, selenium attracted the attention of many researchers for its antioxidative applications. Research studies have found that selenium plays a key role in redox regulation as a ROS modulator and as a catalytic cofactor of endogenous antioxidative systems.
Our research study revealed the advantages of preparing electrochemical depositions of selenium as sensitive interfaces for peroxynitrite detection and quantification. In this regard, we fabricated highly sensitive and selective electrochemical sensors from a solution contains selenium dioxide in acidic medium. A series of glassy carbon electrodes (GCEs) have been modified with selenium nanoparticles, while another series of GCEs were modified with selenium-decorated graphene nanostructures for comparison purposes. The morphology and surface chemistry of the selenium and selenium-decorated graphene nanostructures were characterized using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX). The electrochemical catalytic activities of these platforms were measured using cyclic voltammetry and chronoamperometry. The particle size of the prepared interfaces was determined by microscopic imaging particle analysis.
It was shown that elemental selenium nanoparticles incorporated into graphene sheets enhanced the sensitivity toward peroxynitrite. Selenium tends to stimulate the current response to aliquots of peroxynitrite in solution. Additionally, it enabled the use of fewer positive potentials, resulting in better differentiation between peroxynitrite and other analytes that are sensitive to more positive potentials.
(Invited, Digital Presentation) Circularly Polarized Photoluminescence from Nanostructured Arrays of Light Emitters
Authors: Ferry Vivian 
Published: July 2022

Metasurfaces offer compact routes to spatial and polarization control of luminescence from nearby emitters. The most common integration strategy is to coat a patterned metamaterial or metasurface with a film of light emitting material. For example, structures such as arrays of Au nanorods coated with achiral light emitters exhibit circularly polarized photoluminescence at specific outcoupled angles. However, the degree of circular polarization in these systems is limited to relatively low values, and does not coincide with the angles with high photoluminescence intensity.
This talk will discuss an alternative strategy, where the light emitters are patterned instead. We show that this structure offers several advantages: rather than averaging over the contributions of emitters in many different locations, this system exhibits highly directional photoluminescence with high degrees of circular polarization. Most importantly, the photoluminescence intensity is high at the same angles where the degree of circular polarization is high.
These patterned light-emitting nanostructures are formed using direct-write electron beam lithography on semiconductor nanocrystals. This versatile method is capable of forming structures with aspect ratios greater than 2 and feature sizes as small as 30 nm, photoluminescence is retained after patterning, and the system is robust to multiple patterning steps.
(Invited) Enhancement of Light Emission in Luminescent Structures within Nano-Arrays
Authors: Biswas Rana , Peer Akshit , Zhang Yu 
Published: July 2022

Nanostructures can dramatically alter the light emission in luminescent structures by strongly altering the photonic densities of states at the location of the luminescent emitter. We describe and develop two complementary platforms that tailor luminescent emission through i) quantum dots in nanocup arrays and ii) corrugated nanoarrays in organic light-emitting structures.
We fabricated nanocup arrays with pitch ~750 nm by replica molding in polymer molds. A thin non-conformal gold film was sputter-deposited on the polymer film with angle-directed deposition. The gold film was continuous with a variation of spatial thickness, with the film being optically thin at the bottom of the nanocup [1]. Optical measurements revealed an extraordinary optical transmission (EOT) peak at a wavelength slightly smaller than the pitch. Although no holes were etched in the film the optically thin metal at the bottom allowed resonant light transmission. This is a simple pathway to fabricate large area (>cm2) nano-arrays with EOT without expensive lithography which limits such nano-arrays to very small areas. Quantum dots were embedded in these nanoarrays and revealed a marked reduction of photo-luminescence lifetime by ~4 compared to the control samples, when the emitting wavelength was tuned to the optical resonance of the nanoarray. Scattering matrix and FDTD simulations both show an enhancement of the field by a factor >100. The optically enhanced field in nanocups enhanced the spontaneous emission of embedded quantum dots. The simulated Purcell factor is enhanced by >80 at the bottom of the nanocup, and by a factor of 3-15 averaged over the nanocup height, in agreement with measured photoluminescence lifetimes that decreased by a factor of ~4 for a quantum dot ensemble.
We also study and simulate light emission from organic light emitting diodes (OLEDs) -where only 20% of the light is emitted to air and remainder (~80%) is trapped as internally waveguided modes and surface plasmon modes at the cathode-organic interface. We develop rigorous scattering matrix simulations [2] to demonstrate the emission of light can be increased by enhancement factors >3, when the OLEDs are integrated with periodic nanoarrays. The emissive region conformally follows the periodicity of the nano-array. The periodic nanostructures diffract trapped waveguided modes and plasmonic modes to the air cone and are a pathway to achieving light outcoupling efficiencies exceeding 60%. The predicted dependence of the outcoupled light emission on the pitch and height of the nano-arrays will be presented.

Acknowledgements: Partially supported by NSF grants CMMI-1265844 and CMMI-170648.

References:

[1] A. Peer and R. Biswas, Nanoscale
8, 4657 - 4666 (2016)
[2] Y. Zhang, R. Biswas, ACS Omega
6, 13, 9291–9301 (2021).

Figure 1
(Invited) Biodegradable Organic Electronics: Degradation of Eumelanin Studied by Fluorescence Spectroscopy
Authors: Santato Clara 
Published: July 2022

A paradigm shift in resource exploitation and e-waste management is needed to promote sustainability in electronics. Reusing and recycling electronic devices is not only environmentally desirable but also economically viable and increasingly socially acceptable. A promising route to alleviate the environmental footprint of electronics is based on the use of abundant materials, novel production schemes involving non-toxic materials (through green chemistry processes), and eco-design of devices that includes environmentally acceptable end-of-life scenarios. Within this context, we integrate biosourced electro- and photo-active organic electronic materials, such as melanin, indigo, tannin and lignin derivatives (some of these readily available from biomass feedstock, abundant in Canada) into electronic and energy storage devices, such as transistors and
batteries. Biosourced organic electronic materials can be biodegradable. As such, they offer the opportunity for an environmentally benign device end-of-life scenario (as opposed to the present accumulation of e-waste).
The melanin biopigment family serves as a prototypical environmentally benign class of materials for sustainable organic electronics and its powering elements. Among melanins, eumelanin is a brown-black type found in the human body, other mammals, reptiles, amphibians, and fishes as well as in invertebrates, such as cuttlefish and insects. Sepia Melanin (natural eumelanin) is a type of biosourced eumelanin extracted from the ink sac of cuttlefish. Synthetic eumelanin is commercially available (indicated here as Sigma eumelanin).
We recently reported on encouraging studies on the biodegradability of eumelanin in industrial compost conditions (Di Mauro, E., Rho, D. & Santato, C. Biodegradation of bio-sourced and synthetic organic electronic materials towards green organic electronics. Nature Communications, https://doi.org/10.1038/s41467-021-23227-4); unfortunately, we did not report on intermediates of the biodegradation process. Insight on intermediates is expected to bring about an increase of the mineralization rate of eumelanin. Here, we will discuss possible oxidative degradation pathways of the biopigment eumelanin tin industrial compost conditions hrough fluorescence spectroscopy. Indeed, literature reports that oxidized (by oxidative cleavage of the quinoid structure of the indole moiety), naturally occurring eumelanin can give a lipofuscin-like yellow fluorescence.