Electron Storage Research Articles

CETASim: A numerical tool for beam collective effect study in storage rings

We developed a 6D multi-particle tracking program CETASim in C++ to simulate intensity-dependent effects in electron storage rings. The program can simulate the beam collective effects due to short-range/long-range wakefields for single/coupled-bunch instability studies. It also features the simulation of interactions among charged ions and the trains of electron bunches, including both fast ion and ion trapping effects. The bunch-by-bunch feedback is also included so that the user can simulate the damping of the unstable motion when its growth rate is faster than the radiation damping rate. The particle dynamics is based on the transfer maps from sector to sector, including the nonlinear effects of amplitude-dependent tune shift, high-order chromaticity, and second-order momentum compaction factor. Users can also introduce a skew quadrupole useful for emittance sharing and exchange studies. This paper describes the code structure, the physics models, and the algorithms used in CETASim. We also present the results of its application to the PETRA-IV storage ring.

Biomimetic Redox Capacitor To Control the Flow of Electrons.

In biological systems, electrons, energy, and information "flow" through the redox modality, and we ask, does biology have redox capacitor capabilities for storing electrons? We describe emerging evidence indicating that biological phenolic/catecholic materials possess such redox capacitor properties. We further describe results that show biomimetic catecholic materials are reversibly redox-active with redox potentials in the midphysiological range and can repeatedly accept electrons (from various reductants), store electrons, and donate electrons (to various oxidants). Importantly, catechol-containing films that are assembled onto electrode surfaces can enhance the flow of electrons, energy, and information. Further, catechol-containing films can serve as redox-based interactive materials capable of actuating biological responses by turning on gene expression from redox-responsive genetic circuits. Looking forward, we envision that the emerging capabilities for measuring dynamic redox processes and reversible redox states will provide new insights into redox biology and will also catalyze new technological opportunities for information processing and energy harvesting.

Asymmetric influence of the amplitude-dependent tune shift on the transverse mode-coupling instability

At the 3 GeV ring of the MAX IV Laboratory, a fourth-generation ring-based synchrotron light source, an asymmetric influence of the sign of the amplitude-dependent tune shift (ADTS) on the transverse mode-coupling instability has been observed. Measurements of the instability, in dedicated single-bunch experiments at low chromaticity, revealed a significant dependence of the dynamics of the instability above threshold on the sign of the ADTS. While for a negative sign of the ADTS, the crossing of the instability does not lead to a loss of beam current, a positive sign results in the loss of 40% or more of the beam current at the threshold. In order to investigate the observed asymmetry, the systematic measurement of beam dynamics above the threshold has been conducted in combination with particle tracking simulations with 2 and theoretical calculations of the Landau damping due to the ADTS. The findings point toward an influence of the Landau damping in combination with the low synchrotron frequency, which indicates that this effect could become relevant in the future low-emittance electron storage rings. Published by the American Physical Society 2024

Porous biochar supported PET plastic waste MOF heterostructure as a novel, efficient and recyclable catalyst for acetaminophen degradation

Herein, the innovative hybrid photocatalyst PET-based Zn-MOF on orange peel biochar (BC)(PZM/BC) was designed and synthesized via the hydrothermal method. Electrochemical methods have been used to demonstrate the action of the PET-MOF in the PZM/BC photocatalyst as a medium for electron transfer. The latter involved the synthesis of a zinc-containing metal–organic framework (MOF) in which the linkers were derived from the depolymerization of polyethylene terephthalate (PET) originating from plastic wastes. According to research, the catalytic reactions are sped up when porous BC and linker PET are assimilated into PZM/BC photocatalyst hetero-junction. Furthermore, BC stored electrons under light and released these electrons under dark conditions. When BC was combined with PET-MOF, the electrons on the biochar activated the catalytic redox activity of acetaminophen. Additionally, it lowers the reassimilation rate due to the combined meshed nanostructures and functionality of PET-MOF and PZM/BC. UV–Vis DRS, Mott-Schottky, Photoluminescence(PL), and Electrochemical Impedance spectra(EIS) results showed that the PZM/BC exhibited efficient spatial separation and transportation of photogenerated charge carriers and exhibited superior photocatalytic ability. Electron spin resonance(ESR) analysis confirmed that ⋅OH and h+ were the predominant radical species responsible for the degradation of acetaminophen(ACT). The optimum conditions for ACT removal were observed at pH 6.07, with a PZM/BC dosage of 0.1 g L−1, and an initial ACT concentration of 50 mg L−1, highlighting the pivotal role of the PZM/BC system in ACT degradation. Furthermore, potential photocatalytic degradation pathways of ACT were inferred renders on the identified intermediates which are responsible for the degradation of refractory intermediates. Regeneration trials were carried out to assess the stability of the photocatalyst. Additionally, the degraded intermediates generated during the degradation processes were examined, providing a comprehensive elucidation of the degradation mechanism.Graphical

Oxygen and Electron Storage Effects in W-Modified Ceria Catalysts for Ammonia Conversion.

Tungsten-modified CeO2 is an excellent catalyst for the catalytic conversion of ammonia. However, the geometric and electronic properties of this catalyst and the detailed reaction mechanisms are not well understood. In this work, the potential configurations of various monomer tungsten oxides supported on the CeO2(111) surface (WOX(x=0-4)/CeO2(111)) are systematically studied and their relative stabilities are evaluated by using on-site Coulomb interaction corrected density functional theory calculations. Their performances are also investigated in enhancing the catalytic efficiency of NH3 adsorption and activation. It is found that the WOx clusters can always form tetrahedron-like structures on the CeO2(111) surface, and the CeO2(111) can exhibit both oxygen- and electron-storage roles to help the WOX maintain such tetrahedron-like WO4 structures and keep the W species at the highest 6+ state. Moreover, the flexibility of the tetrahedral WO4 structure leads to the preferential heterolytic NH3 dissociation at the WO sites, forming stable WNH2 and OH species. This study deepens the understanding of the unique oxygen- and electron-storage effects of the CeO2 support, it also provides valuable insights into the extraordinary catalytic properties of the W-modified CeO2 in NH3 conversion, paving the way for the rational design of more efficient CeO2-based NH3 treatment catalysts.

Enhanced photocathodic protection performance of TiO2/SnO2/CdIn2S4 composites for 304 stainless steel in marine environments

In humid and saline environments, metal corrosion leads to significant economic losses, necessitating enhanced anti-corrosion methods. This study aims to enhance the photocathodic protection (PCP) performance of TiO2 nanotubes (NTs) by incorporating SnO2 quantum dots (QDs) and CdIn2S4 nanoflowers (NFs). TiO2 NTs were fabricated on titanium substrates via anodization, followed by successive deposition of SnO2 QDs and CdIn2S4 NFs using immersion and hydrothermal methods. The composite materials were characterized using SEM, TEM, XRD, and XPS. The PCP performance was evaluated through electrochemical tests on 304 stainless steel (304ss). The TiO2/SnO2/CdIn2S4 (T/S/C) composite exhibited a photocurrent density seven times that of pure TiO2 NTs, indicating significantly enhanced separation ability. The composite also demonstrated a notable open-circuit potential (OCP) of −1045 mV vs. SCE. Furthermore, T/S/C could provide delayed protection for up to 10 h in the dark, indicating its electron storage capability. The T/S/C composite material enhances the corrosion resistance of 304ss, offering a promising approach for practical anti-corrosion applications.

Enhanced photocathodic protection performance of Co3S4 nanoparticles modified porous BiVO4 composites for 304 stainless steel

A nanoporous Co3S4/BiVO4 composites were successfully fabricated via electrodeposition, immersion and oil-bath heating methods. ZIF-67 was used as a cobalt source and template. Co3S4/BiVO4 obtained by treatment for 6 h displayed the best photocathodic protection (PCP) performance. Under light, Co3S4–6 h/BiVO4 reduced the potential of 304 stainless steel (SS) to −490 mV vs. SCE, which was 200 mV below that of pure BiVO4. In addition, the photocurrent densities of 304 SS coupled with Co3S4–6 h/BiVO4 were up to 13 μA cm−2, which was more than 4 times that of pure BiVO4. Remarkably, the Rct of 304 SS coupled with Co3S4–6h/BiVO4 (142.6 Ω·cm2) was 1/27 of that of pure BiVO4 (3918 Ω·cm2). The outstanding PCP property of Co3S4/BiVO4 can be owed to the synergistic effects of strong visible light absorption, improved charge transfer efficiency, and enhanced electron storage capacity. These advantages make Co3S4/BiVO4 a promising candidate for providing effective PCP effects on metals.

Enhancing the photoelectrochemical performance of TiO2 photoanode by employing carbon nanoparticles as electron reservoirs and photothermal materials.

Photoelectrochemical (PEC) water splitting is regarded as a potential technique for converting solar energy. However, the fast charge recombination and slow water oxidation kinetics significantly have hindered its practical application. It is found that an elevation in operation temperature can activate the charge transport in the photoanodes. Here, a strategy was performed that carbon nanoparticles were employed to TiO2 nanorods, acting as electron reservoirs as well as photothermal materials. More specifically, a record photocurrent density of 1.62mAcm-2 at 1.23V vs. RHE has been achieved, accompanied by a high charge separation efficiency of 96% and a long-term durability for 8h. The detailed experimental results reveal that under NIR light irradiation, the synergistic effect between electron storage and temperature rise leads to accelerated charge transport in the bulk and water oxidation kinetics on the surface. This research offers a new perspective on how to boost the PEC performance of photoelectrodes.

Hydrogen-bond enhanced interior charge transport and trapping in all-fiber triboelectric nanogenerators for human motion sensing and communication

Maximizing charge density output within confined tribolayer areas is crucial for advancing triboelectric nanogenerator (TENG) performance. While conventional methods primarily focus on enhancing current density by modifying the surface properties of tribo-surfaces, the impact of dipole-dipole interactions between polymer molecular chains in the fibrous tribomaterials has been underexplored. This study reveals that intermolecular dipole-dipole interactions, mediated by hydrogen bonding between chitosan and nylon66 molecular chains, serve as effective bridging mechanisms that substantially boost TENG current density. Furthermore, we developed a breathable and antibacterial electrode by depositing silver nanowires (AgNWs) on the tribolayer surfaces. To prevent air breakdown resulting from excessively high current density, multiwalled carbon nanotubes (MWCNTs) were integrated to enhance electron transfer and storage. The structure we constructed achieved an optimized performance with a high voltage of 335 V, current density of 194.5 mA m−2 and power density of 65.1 W m−2, which demonstrates outstanding performance compared to previously obtained results. Finally, the prepared SWS-TENG was attached to the fingertips, wrist, and neck to track the physiological signals of the human state during standing, walking, and running. In addition, the integration of Morse code functionality introduces new possibilities for healthcare, particularly for non-verbal patients, enabling non-invasive communication of symptoms and emotions. This technology demonstrates significant potential as a versatile and non-invasive tool for point-of-care (PoC) and biomedical applications when deployed on various parts of the human body.

MoS2/CuS/g-C3N4 double S-scheme with charge storage ability for efficient photocatalytic H2 production

The photocatalytic H2 production technology exhibits promising potential in addressing the challenges of environmental pollution and energy crisis. In this work, CuS particles decorated MoS2 seaweed spheres (MoS2/CuS) were synthesized through a hydrothermal method, then they are loaded on the surface of g-C3N4 nanosheets using a solvent evaporation strategy to form MoS2/CuS/g-C3N4 double S-scheme heterojunction. The investigation reveals the H2 production rate of 25 wt% MoS2/CuS/g-C3N4 can reach up to 1438 μmol·g-1·h-1, which is 14.8-fold of g-C3N4 (97 μmol·g-1·h-1). Further studies indicate that the introduction of MoS2/CuS can broaden the light absorption range, increase electrochemical specific surface area, reduce the activation energy for H2 production and increase hydrophilicity of the composite. Especially, CuS can suppress carrier recombination effectively through its electron storage and release ability. Based on the experimental and theoretical analysis of band structures, the charge transfer in MoS2/CuS/g-C3N4 shares optimized double S-scheme charge transfer pathways with a dual reduction site, leading to an enhanced H2 evolution kinetics. This work offers valuable insights for the advancement of novel double S-scheme heterojunctions, showcasing their potential in energy storage and photothermal enhancement effects.

Dual-energy electron storage ring

A dual-energy electron storage ring is a novel concept initially proposed to cool hadron beams at high energies. The design consists of two closed rings operating at significantly different energies: the low-energy ring and the high-energy ring. These two rings are connected by an energy recovery linac (ERL) that provides the necessary energy difference. The ERL features superconducting radio-frequency (SRF) cavities that first accelerate the beam from the low energy EL to the high energy EH and then decelerate the beam from EH to EL in the next pass. The different SRF cavities in the ERL section can be adjusted based on the applications. In this paper, we present a possible layout of a dual-energy electron storage ring. The preliminary optics of the ring is designed to optimize chromaticity correction, dynamic aperture, momentum aperture, beam lifetime, radiation damping, and intrabeam scattering effects. The primary focus of this paper is on the stability conditions and beam dynamics studies associated with this storage ring. Published by the American Physical Society 2024

Transverse echo effect induced multiple harmonic generation scheme in an electron storage ring

Multiple harmonic generation is a key issue for coherence radiation generated by an electron beam modulated by the seeding laser. A new multiple harmonic generation scheme by combining the angular dispersion-induced microbunching (ADM) with the transverse echo effect, which can be easily generated by using pulsed dipoles, a pulsed quadrupole and a pulsed multipole, is investigated in a multi-bend achromatic storage ring. Simulation results demonstrate a triple of harmonic number compared to the case of pure ADM, making it possible to generate coherent extreme ultraviolet radiation in storage rings.

Revealing the effect regularity of cations on electron storage capacity of poly(heptazine imide) in “dark photocatalysis”

As a crystalline carbon nitride material, poly(heptazine imide) (abbreviated as PHI) exhibits higher photoinduced charge separation performance than traditional melon-based carbon nitride. The excellent charge separation is mainly attributed to the fact that the photoinduced electrons can be captured by cations (such as K+ and H+) and further stored in the PHI framework with the presence of sacrificial agents (such as methanol). Due to this special property, the stored electrons can be used for delayed H2O2 or H2 production in the “dark photocatalysis” field. Nevertheless, the effect regularity of cations on the electron storage capacity of PHI is still not clear. In this work, this problem has been preliminarily revealed. The electron storage capacity of a series of PHI materials has been quantified by the H2O2 production test in dark conditions. The result indicates that the electron storage capacity of PHI samples shows a volcano curve with the alkali metal ion content. Based on experimental tests and theoretical simulations, it is concluded that the electron storage capacity of PHI is related to the conductivity of the cation and its binding force for photogenerated electrons.

Fabrication of bio-abiotic hybrid living hydrogel for bifunctional electrochemical conversion

Design and intelligent use renewable natural bioenergy is an important challenge. Electric microorganism-based materials are being serve as an important part of bioenergy devices for energy release and collection, calling for suitable skeleton materials to anchor live microbes. Herein we verified the feasibility of constructing bio-abiotic hybrid living materials based on the combination of gelatin, Li-ions and exoelectrogenic bacteria Shewanella oneidensis manganese-reducing-1 (MR-1). The gelatin-based mesh contains abundant pores, allowing microbes to dock and small molecules to diffuse. The hybrid materials hold plentiful electronegative groups, which effectively anchor Li-ions and facilitate their transition. Moreover, the electrochemical characteristics of the materials can be modulated through changing the ratios of gelatin, bacteria and Li-ions. Based on the gelatin-Li-ion-microorganism hybrid materials, a bifunctional device was fabricated, which could play dual roles alternatively, generation of electricity as a microbial fuel cell and energy storage as a pseudocapacitor. The capacitance and the maximum voltage output of the device reaches 68 F·g-1 and 0.67 V, respectively. This system is a new platform and fresh start to fabricate bio-abiotic living materials for microbial electron storage and transfer. We expect the setup will extend to other living systems and devices for synthetic biological energy conversion.

Unlocking high-efficiency charge storage: Co-assembled nanoparticles of lignin and polyaniline molecules

Redox-active lignin rich in phenolic hydroxyl groups is an ingenious charge storage material. However, its insulating nature limits the storage/release of electrons and requires the construction of electron transfer channels within it. Herein, nanoparticles (PANI/DKL-NPs) are prepared by co-assembly via π–π interactions between conducting polyaniline (PANI) and demethylated Kraft lignin (DKL) molecules for the first time, and rapid electron transfer inside DKL is achieved. The co-assembled PANI/DKL-NPs consist of interpenetrating structures of PANI and DKL at the molecular scale, and the content of PANI molecules interspersed within them is controllable. Meanwhile, the extensive and abundant mesoporous structure in nanoscale PANI/DKL-NPs facilitates ion transport and electron storage. Based on this favorable microstructure, the specific capacitance of PANI/DKL-NPs at 1 A·g−1 is as high as 532 F·g−1, which is 780 % and 90.68 % higher compared to DKL-NPs and PANI-NPs, respectively. Meanwhile, the rate performance of PANI/DKL-NPs is significantly enhanced than that of DKL-NPs (33.11 %) and comparable to that of PANI-NPs (more than 69 %). Furthermore, the symmetric supercapacitor (PANI/DKL-NPs//PANI/DKL-NPs) assembled from it achieves a high energy density of 27.49 Wh·kg−1 at 400 W·kg−1 power density, and superb flexibility and mechanical stability. Therefore, the co-assembly of DKL and PANI will effectively stimulate the energy storage potential of lignin, providing a practical pathway to promote the development of biopolymers in energy storage.

Expediting Photo‐Charging of Semiconductors through a Bipolar Charge Storage Junction for Responsive Dark Photocatalysis

AbstractPhoto‐charging of semiconductors stores electrons for decoupled solar utilization, overcoming intermittent sunlight availability. However, the sluggish photo‐charging process impedes responsive charge storage. Herein, a bipolar charge storage junction is demonstrated to expedite the photo‐charging process within a renowned ionic‐CN/Co3O4 configuration, benefiting from their mismatched photo‐charging kinetics. Rapid photo‐hole storage associated with structural evolution at geometrically dependent Co sites in Co3O4 improves sluggish electron storage for ionic‐CN, while slow recovery of altered [CoO4] and [CoO6] structures delayed electron‐hole recombination. By passivating individual atomic sites, rapid hole storage is attributed to synergistic contributions of tetrahedral Co2⁺ and octahedral Co3⁺ species. The bipolar charge storage junction is photo‐charged at 0.86 A g−1, rivaling the electrical charging rate in ion batteries. With 60 s photo‐charging, the junction yields 0.27 mmol g−1 of “dark” hydrogen, the benchmark for such a short photo‐charging timeframe. This proof‐of‐concept design empowers the fast photo‐charging ability of bipolar charge storage junctions, advancing responsive photo‐charge storage for decoupled solar utilization.

Enhancing the production of reactive oxygen species in the rhizosphere to promote contaminants degradation in sediments by electrically strengthening microbial extracellular electron transfer

The production of reactive oxygen species (ROS) in the rhizosphere is limited by the low extracellular electron transfer capacity of indigenous microorganisms. In the present study, electrical stimulation was used to promote the generation of rhizospheric ROS by accelerating extracellular electron transfer. The result showed that •OH concentrations in the electrically stimulated group (ES group) exceeded the control group by 15.76 %. Accordingly, the removal rate of the target pollutant (i.e., 2,4-dichlorophenol, and sulfamethoxazole) was 20.01 %−24.80 % higher in the ES group than in the control group. The sediment of the ES group had a higher capacity (30.55 %) and a lower electrical resistance (29.15 %) compared to the control group, which subsequently promoted the dissimilatory iron reduction to produce Fe(II) for triggering a Fenton-like process. The increased extracellular respiratory capacity under electrical stimulation could be attributed to the polarization of C-N and CO bonds, which provided more electron storage sites and thus participated in proton-coupled electron transfer. In addition, the concentration of ATP and co-enzymes (NADH/NAD+ and Complex I/Complex III), reflecting electron exchange within respiratory chains, increased distinctly under electrical stimulation. Applying electrical stimulation seemed feasible to increase ROS production and contaminant degradation in the rhizosphere, deepening the understanding of electrical stimulation to promote the production of ROS in the natural system.

Main‐Group Metal‐Nonmetal Dynamic Proton Bridges Enhance Ammonia Electrosynthesis

The electrochemical nitrogen reduction reaction is a crucial process for the sustainable production of ammonia for energy and agriculture applications. However, the reaction’s efficiency is highly dependent on the activation of the inert N≡N bond, which is hindered by the electron back‐donation to the π* orbitals of the N≡N bond, resulting in low eNRR capacity. Herein, we report a main‐group metal‐non‐metal (O‐In‐S) eNRR catalyst featuring a dynamic proton bridge, with In‐S serving as the polarization pair and O functioning as the dynamic electron pool. In‐situ spectroscopic analysis and theoretical calculations reveal that the In‐S polarization pair acts as asymmetric dual‐sites, polarizing the N≡N bond by concurrently back‐donating electrons to both the πx* and πy* orbitals of N2, thereby overcoming the significant band gap limitations, while inhibiting the competitive hydrogen evolution reaction. Meanwhile, the O dynamic electron pool acts as a “repository” for electron storage and donation to the In‐S polarization pair. As a result, the O‐In‐S dynamic proton bridge exhibits exceptional NH3 yield rates and Faradaic efficiencies (FEs) across a wide potential window of 0.3 V, with an optimal NH3 yield of 80.07 ± 4.25 μg h‐1 mg‐1 and an FE of 38.01 ± 2.02%, outperforming most previously reported catalysts.

Main-Group Metal-Nonmetal Dynamic Proton Bridges Enhance Ammonia Electrosynthesis.

The electrochemical nitrogen reduction reactionis a crucial process for the sustainable production of ammoniafor energy and agriculture applications. However, the reaction's efficiency is highly dependent on the activation of the inert N≡N bond, which is hindered by the electron back-donation to the π* orbitals of the N≡N bond, resulting in low eNRR capacity. Herein, we report a main-group metal-non-metal (O-In-S) eNRR catalyst featuring a dynamic proton bridge, with In-S serving as the polarization pair and O functioning as the dynamic electron pool. In-situ spectroscopic analysis and theoretical calculations reveal that the In-S polarization pair acts as asymmetric dual-sites, polarizing the N≡N bond by concurrently back-donating electrons to both the πx* and πy* orbitals of N2, thereby overcoming the significant band gap limitations, while inhibiting the competitive hydrogen evolution reaction. Meanwhile, the O dynamic electron pool acts as a "repository" for electron storage and donation to the In-S polarization pair. As a result, the O-In-S dynamic proton bridge exhibits exceptional NH3 yield rates and Faradaic efficiencies (FEs) across a wide potential window of 0.3 V, with an optimal NH3 yield of 80.07 ± 4.25 μg h-1 mg-1 and an FE of 38.01 ± 2.02%, outperforming most previously reported catalysts.

(Invited) Surface State Modulation of Colloidal Quantum Dots and Construction of Quantum Dot Based Infrared Detectors

Near-infrared photodetection and imaging devices play an important role in fields such as biological detection, information communication, military meteorology, etc. Traditional imaging devices require integration with readout circuits, and the complex integration process limits the development of infrared imaging systems. Lead sulfide colloidal quantum dots have excellent photoelectric properties in the infrared region, with a tunable bandgap width ranging from 0.4 to 1.5 eV, and spectral response covering below 2400 nm. Lead sulfide quantum dot films exhibit high absorption coefficients in the infrared region and excellent carrier mobility. In recent years, the performance of infrared detectors based on quantum dot systems has rapidly improved, and they are expected to develop into a new type of infrared detection and imaging technology. The speaker's team has combined infrared quantum dots with visible light quantum dots to prepare a simple, low-cost, and efficient infrared upconversion imaging device. By using the method of inducing band bending through interface electron storage, the efficiency of carrier tunneling and photon conversion has been improved, and the application of this technology in biological imaging has been preliminarily demonstrated. This report will introduce the development of quantum dot infrared detection materials and devices in recent years, as well as the research progress of the speaker's team in this area.