Proton Activation Research Articles

Proton‐Modulated Resistive Switching in a Synapse‐Like Tyrosine‐Rich Peptide‐Based Memristor

AbstractArtificial intelligence has become an essential part of the daily lives and has revolutionized various sectors, including healthcare, finance, transportation, and entertainment. With a substantial increase in processed data, neuromorphic devices that replicate the operation of the human brain have been emphasized owing to their superior efficiency. Typical neuromorphic devices focus on constructing synapse‐like structures. However, biological synapses have more complex mechanisms for efficient data processing. One of the most prominent mechanisms is proton activation, which forms an ion concentration gradient prior to the transmission of neurotransmitters and plays a key role in efficient computation. In this study, proton‐mediated signaling at biological synapses is successfully replicated by fabricating a proton‐modulated memristor device using a tyrosine‐rich peptide film. The ionic input of the memristor is controlled by applying a voltage to proton‐permeable PdHx contacts in a hydrogen atmosphere, thus successfully adjusting the resistive switching behavior. Remarkable improvements in resistive switching and computing performance are observed through proton injection, analogous to “proton‐mediated signaling” at the actual synapse. It is believed that this study proposes a new paradigm for designing biorealistic devices and provides inspiration for precisely controllable ion‐based neuromorphic devices.

A novel simultaneous abatement of bromate and diphenyl phosphate using the freezing process

The purification of bromate (BrO3-)-contaminated water has become a challenge because of its persistence and adverse effects. Furthermore, there has been concern over the release of byproducts, such as diphenyl phosphate (DPHP), from flame retardants in wastewater treatment plant (WWTP). In this study, we designed the water treatment system for the oxidation of DPHP accompanied by bromate (BrO3-) reduction via freezing the solution. A sample containing 10 μM DPHP, 100 μM Br-, and 50 μM BrO3-, with a pH of 3 was frozen at -20oC, approximately 25 μM BrO3- was reduced, and DPHP was fully eliminated after a 0.5 h reaction time. Conversely, these reactions did not advance in water at 20oC. This increase in the rate of chemical reaction in ice is the consequence of the freeze concentration effect, which refers to the extraction of dissolved chemical species into the liquid-like regions of the polycrystalline ice micro-structure during the freezing of the solution. The redox reactions among DPHP, Br-, and BrO3- become thermodynamically favorable due to the distinctive environment in the liquid brine in ice. The efficiency of the DPHP oxidation significantly increased with an increase in BrO3- concentration, and vice versa. The Br-/BrO3--induced HOBr production is proposed as a primary oxidant for DPHP degradation. The proton activity (pH) has a significant influence on the reaction efficiency. The low freezing temperature accelerated the reaction kinetics of DPHP degradation and BrO3- reduction. The results of this study indicate the possibility of utilizing ice chemistry for the BrO3- reduction that concomitantly removes DPHP for water treatment. This environmentally friendly water treatment method can be considered to implement in regions with a cold climate.

Through-bond and through-space radiofrequency amplification by stimulated emission of radiation

Radio Amplification by Stimulated Emission of Radiation (RASER) is a phenomenon observed during nuclear magnetic resonance (NMR) experiments with strongly negatively polarized systems. This phenomenon may be utilized for the production of very narrow NMR lines, background-free NMR spectroscopy, and excitation-free sensing of chemical transformations. Recently, novel methods of producing RASER by ParaHydrogen-Induced Polarization (PHIP) were introduced. Here, we show that pairwise addition of parahydrogen to various propargylic compounds induces RASER activity of other protons beyond those chemically introduced in the reaction. In high-field PHIP, negative polarization initiating RASER is transferred via intramolecular cross-relaxation. When parahydrogen is added in Earth’s field followed by adiabatic transfer to a high field, RASER activity of other protons is induced via both J-couplings and cross-relaxation. This through-bond and through-space induction of RASER holds potential for the ongoing development and expansion of RASER applications and can potentially enhance spectral resolution in two-dimensional NMR spectroscopy techniques.

Strategically Modulating Proton Activity and Electric Double Layer Adsorption for Innovative All-Vanadium Aqueous Mn2+/Proton Hybrid Batteries.

Aqueous Mn-ion batteries (MIBs) exhibit a promising development potential due to their cost-effectiveness, high safety, and potential for high energy density. However, the development of MIBs is hindered by the lack of electrode materials capable of storing Mn2+ ions due to acidic manganese salt electrolytes and large ion radius. Herein, the tunnel-type structure of monoclinic VO2 nanorods to effectively store Mn2+ ions via a reversible (de)insertion chemistry for the first time is reported. Utilizing exhaustive in situ/ex situ multi-scale characterization techniques and theoretical calculations, the co-insertion process of Mn2+/proton is revealed, elucidating the capacity decay mechanism wherein high proton activity leads to irreversible dissolution loss of vanadium species. Further, the Grotthuss transfer mechanism of protons is broken via a hydrogen bond reconstruction strategy while achieving the modulation of the electric double-layer structure, which effectively suppresses the electrode interface proton activity. Consequently, the VO2 demonstrates excellent electrochemical performance at both ambient temperatures and -20°C, especially maintaining a high capacity of 162mAhg-1 at 5Ag-1 after a record-breaking 20000 cycles. Notably, the all-vanadium symmetric pouch cells are successfully assembled for the first time based on the "rocking-chair" Mn2+/proton hybrid mechanism, demonstrating the practical application potential.

Hybrid Nanoparticles: Ni and Au Decorated with [FeFe]‐Hydrogenase Mimics

Complexes [(μ‐S₂C₂H₄NHR)Fe₂(CO)₆] (R = p‐C₆H₄‐OCO(CH₂)₉Br (3a); R = p‐C₆H₄‐OCO(CH₂)₈CH₃ (3b)) were used as stabilizing agents in the synthesis of Ni@3 and Au@3 nanoparticles (NPs), which are the first reported stable metallic NPs decorated with [(μ‐S₂C₂H₄NHR)Fe₂(CO)₆] moieties. Electrochemical analysis reveals that incorporating the hydrogenase mimic into the NPs lowers the overpotential and enhances proton reduction electrocatalytic activity in organic media. The NPs act similarly to the [Fe₄S₄] cluster in natural enzymes, functioning as an electron reservoir/relay.

Mastering Proton Activities in Aqueous Batteries.

Advanced aqueous batteries are promising solutions for grid energy storage. Compared with their organic counterparts, water-based electrolytes enable fast transport kinetics, high safety, low cost, and enhanced environmental sustainability. However, the presence of protons in the electrolyte, generated by the spontaneous ionization of water, may compete with the main charge-storage mechanism, trigger unwanted side reactions, and accelerate the deterioration of the cell performance. Therefore, it is of pivotal importance to understand and master the proton activities in aqueous batteries. This Perspective commentson the following scientific questions: Why are proton activities relevant? What are proton activities? What doweknow about proton activities in aqueous batteries? How dowebetter understand, control, and utilize proton activities?

Modulating the Microenvironments of Robust Metal Hydrogen-Bonded Organic Frameworks for Boosting Photocatalytic Hydrogen Evolution.

Hydrogen-bonded organic frameworks (HOFs) are outstanding candidates for photocatalytic hydrogen evolution. However, most of reported HOFs suffer from poor stability and photocatalytic activity in the absence of Pt cocatalyst. Herein, a series of metal HOFs (Co2-HOF-X, X=COOMe, Br, tBu and OMe) have been rationally constructed based on dinuclear cobalt complexes, which exhibit exceptional stability in the presence of strong acid (12 M HCl) and strong base (5 M NaOH) for at least 10 days. More impressively, by varying the -X groups of the dinuclear cobalt complexes, the microenvironment of Co2-HOF-X can be modulated, giving rise to obviously different photocatalytic H2 production rates, following the -X group sequence of -COOMe>-Br>-tBu>-OMe. The optimized Co2-HOF-COOMe shows H2 generation rate up to 12.8 mmol g-1 h-1 in the absence of any additional noble-metal photosensitizers and cocatalysts, which is superior to most reported Pt-assisted photocatalytic systems. Experiments and theoretical calculations reveal that the -X groups grafted on Co2-HOF-X possess different electron-withdrawing ability, thus regulating the electronic structures of Co catalytic centres and proton activation barrier for H2 production, and leading to the distinctly different photocatalytic activity.

The plasma membrane inner leaflet PI(4,5)P2 is essential for the activation of proton-activated chloride channels

Proton-activated chloride (PAC) channels, ubiquitously expressed in tissues, regulate intracellular Cl- levels and cell death following acidosis. However, molecular mechanisms and signaling pathways involved in PAC channel modulation are largely unknown. Herein, we determine that phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] of the plasma membrane inner leaflet is essential for the proton activation of PAC channels. PI(4,5)P2 depletion by activating phosphatidylinositol 5-phosphatases or Gq protein-coupled muscarinic receptors substantially inhibits human PAC currents. In excised inside-out patches, PI(4,5)P2 application to the cytoplasmic side increases the currents. Structural simulation reveals that the putative PI(4,5)P2-binding site is localized within the cytosol in resting state but shifts to the cell membrane’s inner surface in an activated state and interacts with inner leaflet PI(4,5)P2. Alanine neutralization of basic residues near the membrane-cytosol interface of the transmembrane helice 2 significantly attenuates PAC currents. Overall, our study uncovers a modulatory mechanism of PAC channel through inner membrane PI(4,5)P2.

Proton Activity and Pathway in Aqueous Organic Redox Flow Battery Electrolyte

Aqueous soluble organic (ASO) redox-active materials have recently shown great promise as alternatives to transition metal ions employed as energy-bearing active materials in redox flow batteries for large-scale energy storage because of their structural tunability, cost-effectiveness, availability, and safety features. However, development so far has been limited to a small palette of organics that are aqueous soluble. This presentation will use fluorenone as an example to showcase how a natively redox-inactive molecule can be tuned to possess two-electron redox reversibility through hydrogenation and dehydrogenation. The modified fluorenone molecules demonstrated high energy density and recorded stable cycling. Furthermore, research has shown the unique chemical-electrochemical coupled redox reactions mechanism; thus, the system rate capabilities can be improved by incorporating suitable hydrogen acceptors that regulate the proton pathway for faster kinetics.Reference:Feng et al., Science 372, 836–840, 2021Feng et al., Joule 7, 1–14, 2023

Regulated Interfacial Proton and Water Activity Enhances Mn2+/MnO2 Platform Voltage and Energy Efficiency

Aqueous zinc battery (AZB) is one of the most promising energy storage systems for large-scale applications due to its high safety, low cost, and environmental friendliness. To match the high capacity of zinc metal (~820 mAh g-1), various cathode materials, such as oxides, open structure analogues, chalcogens, and halogens, have been explored for AZBs. Among them, manganese dioxide (MnO2) has been considered to be one of the most attractive candidates due to its high capacity (~308 mAh g-1 for one-electron transfer) and adequate redox potential (~0.70 V vs. SHE). Recently, the MnO2 dissolution/deposition charge storage mechanism has been demonstrated to further increase the voltage and capacity of Mn-based AZBs. The dissolution/deposition (Mn2+/MnO2) is a two-electron transfer process, which doubles the theoretical capacity of MnO2 cathode to ~616 mAh g-1 and considerably increases the redox potential (~1.229 V vs. SHE). The charge storage via the dissolution/deposition mechanism pushes the aqueous-based energy density even higher, to over 1000 Wh kg-1.However, this charge storage mechanism involves liquid-solid transition, as well as the thermodynamics and kinetics of this reaction are highly dependent on the acidity and interfacial environment. Yet, the opposite effect of interfacial H+ on the dissolution/deposition processes and the role of interfacial H2O are rarely discussed. Here we introduce tetrafluoroborate anion (BF4 -) into the sulfate-based electrolyte to regulate the interfacial H+ and H2O activity. First, BF4 - hydrolysis increases the electrolyte’s acidity, promoting MnO2 dissolution. Second, BF4 - forms an H-bond network with interfacial H2O that assists H+ diffusion while retaining sufficient H2O supply to facilitate MnO2 deposition. As a result, the cathode-free Zn//MnO2 electrolytic cell achieves a high plateau of ~1.92 V and energy efficiency of ~84.23 % in the BF4 - containing electrolyte. Significantly, the cell delivers 1000 cycles at 1 C with ~100 % Coulombic efficiency and a high energy efficiency retention of 93.65 %. Our findings disclose a new strategy to promote Mn2+/MnO2 platform voltage and energy efficiency for future large-scale energy storage systems.

Aspects of Reduced Performance of Proton-Exchange-Membrane Water Electrolysis Via Continuum Modeling

Proton-exchange-membrane water electrolysis (PEMWE) is a technology, where hydrogen is electrochemically produced from water. Efficient industrial-scale production of hydrogen via PEMWE is contingent upon developing systems that are sufficiently resilient to operate under non-ideal operating conditions. Mathematical models can provide insight into the underlying physical mechanisms and inform the development of mitigating strategies. In the current work, a cell-level non-isothermal continuum model that is based on concentrated-solution theory that accounts for multiple ionic mobile species in the membrane and ionomer, energy transport, and fluid flow through porous media, was used to investigate two challenges to PEMWE becoming a viable technology, specifically contamination and hydrogen crossover. In cationic contamination, dissolved salts in the reactant water supplant protons in the membrane and ionomer and significantly increase the applied potentials required for operation. Hydrogen crossover is a concern especially in low-current operational modes, which can arise due to PEMWE powered by variable and cyclical renewable energy sources and can result in the production of combustible gas mixtures.For cation-contaminated cells, simulation results suggest that the uptake of the contaminant cation increased as a function of current density until local conditions in the cathode catalyst layer (cCL) allowed the contaminant desorption to occur. The model suggests that the increased cell potential is primarily due to proton activity losses in the hydrogen evolution reaction within the cCL and that ionic conductivity losses are insufficient to cause the performance losses observed experimentally. Agreement with experimental data lends the model as a possible method or predictive models for PEMWE cell recovery methods. Observations of hydrogen crossover simulations suggest several aspects of hydrogen crossover, which include that localized pressures within the catalyst layers can enhance crossover, bubble-nucleation kinetics limit the exhaust of product gases, and convective fluxes due to electroomostic drag are negligible. An improved understanding of the crossover mechanisms can inform the development of low-crossover designs and mitigation strategies. Figure 1

Raman spectra of oxidized sulfur species in hydrothermal fluids

Raman spectroscopic determination of sulfur species molalities in hydrothermal fluids requires correct assignment and knowledge of the scattering efficiencies of Raman bands. Therefore, we studied the Raman spectra of NaHSO4 and H2SO4 solutions experimentally to 700 °C, and of Na2SO4, NaHSO4, H2SO4, and H2SO3 solutions by ab initio molecular dynamics simulation at 727 °C. The results indicate that the scattering efficiencies of the νs(SO3), νas(SO3), and ν(S–OH) Raman bands of HSO4−(aq) depend on the H+ activity. The asymmetric shape of the νs(SO3) Raman band of HSO4−(aq) becomes more symmetric with increasing temperature, which correlates with decreasing hydrogen bonding in the molecular environment. Proton activity and ion pairing do not have a large effect on the change in the band asymmetry with temperature, and a resonance effect on the band shape is not observed. Therefore, we attribute the asymmetric shape of the νs(SO3) Raman band of HSO4−(aq) mostly to hydrogen bonding of the proton in the H–OSO3− molecule with water in its environment. The AIMD simulations clarify assignments of Raman bands of H2SO40, specifically to νs(SO2) and νas(SO2) at ∼1140 cm−1 and ∼1370 cm−1, to νs(SO4) and νas(SO4) at ∼970 cm−1 and ∼1220 cm−1, and to νs(S–(OH)2) and νas(S–(OH)2) at ∼750 cm−1 and ∼840 cm−1. In addition, the experiments showed that diamond is not inert to H2SO4 at high temperatures as reduction of S(VI) to S(IV) produces SO20 and oxidation of diamond generates CO20.

Modulating the Microenvironments of Robust Metal Hydrogen‐Bonded Organic Frameworks for Boosting Photocatalytic Hydrogen Evolution

AbstractHydrogen‐bonded organic frameworks (HOFs) are outstanding candidates for photocatalytic hydrogen evolution. However, most of reported HOFs suffer from poor stability and photocatalytic activity in the absence of Pt cocatalyst. Herein, a series of metal HOFs (Co2‐HOF‐X, X=COOMe, Br, tBu and OMe) have been rationally constructed based on dinuclear cobalt complexes, which exhibit exceptional stability in the presence of strong acid (12 M HCl) and strong base (5 M NaOH) for at least 10 days. More impressively, by varying the ‐X groups of the dinuclear cobalt complexes, the microenvironment of Co2‐HOF‐X can be modulated, giving rise to obviously different photocatalytic H2 production rates, following the −X group sequence of −COOMe>−Br>−tBu>−OMe. The optimized Co2‐HOF‐COOMe shows H2 generation rate up to 12.8 mmol g−1 h−1 in the absence of any additional noble‐metal photosensitizers and cocatalysts, which is superior to most reported Pt‐assisted photocatalytic systems. Experiments and theoretical calculations reveal that the −X groups grafted on Co2‐HOF‐X possess different electron‐withdrawing ability, thus regulating the electronic structures of Co catalytic centres and proton activation barrier for H2 production, and leading to the distinctly different photocatalytic activity.

Phosphorus and sulfur co-doped nickel molybdate with rich-oxygen vacancies for efficient water splitting

The rational design of high-performance electrocatalysts is essential for promoting the industrialization of electrocatalytic water-splitting technology. Herein, phosphorus and sulfur co-doped nickel molybdate with rich-oxygen vacancies (P, S-NiMoO4) was prepared as an efficient bifunctional self-supporting water-splitting catalyst from the perspective of enhancing the conductivity and optimizing the electronic configurations. The incorporation of P, S and oxygen vacancies greatly enhances the conductivity and charge-transfer efficiency of NiMoO4. Additionally, P and S can serve as proton carriers and electron acceptors to enhance the catalytic activity by accelerating proton activation and high-valent metal generation in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As expected, P, S-NiMoO4 demonstrates efficient bifunctional catalytic activity with an overpotential of only 31/206 mV at 10 mA cm−2 for HER/OER in 1 M KOH. Meantime, the electrolyzer assembled with P, S-NiMoO4 as electrodes requires a voltage of only 1.55 V to achieve a water-splitting current density of 50 mA cm−2 along with good stability over 110 h. This work puts forward a novel approach based on elemental doping and vacancy engineering for the design of effective and enduring catalysts for water splitting.

How Droplets Can Accelerate Reactions─Coacervate Protocells as Catalytic Microcompartments.

ConspectusCoacervates are droplets formed by liquid-liquid phase separation (LLPS) and are often used as model protocells-primitive cell-like compartments that could have aided the emergence of life. Their continued presence as membraneless organelles in modern cells gives further credit to their relevance. The local physicochemical environment inside coacervates is distinctly different from the surrounding dilute solution and offers an interesting microenvironment for prebiotic reactions. Coacervates can selectively take up reactants and enhance their effective concentration, stabilize products, destabilize reactants and lower transition states, and can therefore play a similar role as micellar catalysts in providing rate enhancement and selectivity in reaction outcome. Rate enhancement and selectivity must have been essential for the origins of life by enabling chemical reactions to occur at appreciable rates and overcoming competition from hydrolysis.In this Accounts, we dissect the mechanisms by which coacervate protocells can accelerate reactions and provide selectivity. These mechanisms can similarly be exploited by membraneless organelles to control cellular processes. First, coacervates can affect the local concentration of reactants and accelerate reactions by copartitioning of reactants or exclusion of a product or inhibitor. Second, the local environment inside the coacervate can change the energy landscape for reactions taking place inside the droplets. The coacervate is more apolar than the surrounding solution and often rich in charged moieties, which can affect the stability of reactants, transition states and products. The crowded nature of the droplets can favor complexation of large molecules such as ribozymes. Their locally different proton and water activity can facilitate reactions involving a (de)protonation step, condensation reactions and reactions that are sensitive to hydrolysis. Not only the coacervate core, but also the surface can accelerate reactions and provides an interesting site for chemical reactions with gradients in pH, water activity and charge. The coacervate is often rich in catalytic amino acids and can localize catalysts like divalent metal ions, leading to further rate enhancement inside the droplets. Lastly, these coacervate properties can favor certain reaction pathways, and thereby give selectivity over the reaction outcome.These mechanisms are further illustrated with a case study on ribozyme reactions inside coacervates, for which there is a fine balance between concentration and reactivity that can be tuned by the coacervate composition. Furthermore, coacervates can both catalyze ribozyme reactions and provide product selectivity, demonstrating that coacervates could have functioned as enzyme-like catalytic microcompartments at the origins of life.

The pH paradox

This paper highlights the critical role of pH or proton activity measurements in environmental studies and emphasises the importance of applying proper statistical approaches when handling pH data. This allows for more informed decisions to effectively manage environmental data such as from mining influenced water. Both the pH and {H+} of the same system display different distributions, with pH mostly displaying a normal or bimodal distribution and {H+} showing a lognormal distribution. It is therefore a challenge of whether to use pH or {H+} to compute the mean or measures of central tendency for further environmental statistical analyses. In this study, different statistical techniques were applied to understand the distribution of pH and {H+} from four different mine sites, Metsämonttu in Finland, Felsendome Rabenstein in Germany, Eastrand and Westrand mine water treatment plants in South Africa. Based on the statistical results, the geometric mean can be used to calculate the average of pH if the distribution is unimodal. For a multimodal pH data distribution, peak identifying methods can be applied to extract the mean for each data population and use them for further statistical analyses.

Preparation and electrochromism of amorphous Bi-doped TiO2 film for aqueous-based electrochromic device

Amorphous Bi–TiO2 films with improved electrochromic properties have been successfully fabricated by a facile sol-gel spin-coating technology. The influence of dopant bismuth (Bi) content and sol amount on the electrochromic performance of Bi–TiO2 films was studied. The optimized Bi–TiO2 films show outstanding electrochromic properties, including wide transmittance modulation (ΔT = 74.26 % at 640 nm), short switching times (2.6 s/3 s for bleaching and coloring), and large coloration efficiency (52.77 cm2 C−1). A proton-based electrochromic device was prepared by the amorphous Bi–TiO2 film as the electrochromic film and Cu sheet as the counter electrode. The prepared device has a small operating potential range (1.0 V) in aqueous electrolyte due to the excellent electrochromic performance and high proton activity for the amorphous Bi–TiO2 film. In addition, the device shows excellent performance (ΔT = 67.41 %, 2.5 s/3.9 s for bleaching and coloring), providing an important reference value for the development of high-efficiency electrochromic device.

Fe-N co-doped carbon nanofibers with Fe3C decoration for water activation induced oxygen reduction reaction

ABSTRACT Proton activity at the electrified interface is central to the kinetics of proton-coupled electron transfer (PCET) reactions in electrocatalytic oxygen reduction reaction (ORR). Here, we construct an efficient Fe3C water activation site in Fe-N co-doped carbon nanofibers (Fe3C-Fe1/CNT) using an electrospinning-pyrolysis-etching strategy to improve interfacial hydrogen bonding interactions with oxygen intermediates during ORR. In situ Fourier transform infrared spectroscopy and density functional theory studies identified delocalized electrons as key to water activation kinetics. Specifically, the strong electronic perturbation of the Fe–N4 sites by Fe3C disrupts the symmetric electron density distribution, allowing more free electrons to activate the dissociation of interfacial water, thereby promoting hydrogen bond formation. This process ultimately controls the PCET kinetics for enhanced ORR. The Fe3C-Fe1/CNT catalyst demonstrates a half-wave potential of 0.83 V in acidic media and 0.91 V in alkaline media, along with strong performance in H2-O2 fuel cells and Al-air batteries.

Suppressing proton-induced HER and cathode fading by an aprotic hybrid electrolyte for long-cycle stability of aqueous Na||Zn hybrid batteries

Aqueous zinc metal batteries with unique advantages of intrinsic safety and low cost are considered as one of the most promising next-generation energy-storage technologies. However, their lifespan is significantly constrained by the electrolyte, specifically due to limitations caused by proton-induced HER and dendritic growth at the anode side and dissolution phenomena at the cathode. Unlike most studies on the protic electrolyte systems, herein, a new aprotic hybrid electrolyte of Na/Zn tetrafluoroborate-trimethyl phosphate with ultralow proton activity tuned by reconstruction of hydrogen bonding network and ultrahigh interfacial stability endowed by simultaneous formation of SEI and CEI were designed for the first time. Attributed to the synergistic effect of proton activity attenuation and ZnF2-Zn3(PO4)2 SEI formation, HER-trigged corrosion current was decreased by 96.52%, which leads to an exceptionally high coulombic efficiency up to 99.63%, and operational lifespan exceeding 2000 hours at 1 mA cm−2/ 1 mAh cm−2 for Zn||Cu asymmetric cell and Zn||Zn symmetric cell, respectively. Furthermore, the suppression of excess hydrated proton co-insertion reaction and construction of inorganic-organic CEI enabled the PBAs||Zn full cell a prolonged cycling life of 6000 cycles with an ultralow decay rate of 0.004% per cycle. The special electrolyte utilizing cheap tetrafluoroborate salts in conjunction with cost-effective PBA cathode and Zn anode provides a new choice for low-cost, high-safety, non-toxic batteries for practical applications.

Novel Palladium Hydride Surface Enabling Simultaneous Bacterial Killing and Osteogenic Formation through Proton Capturing and Activation of Antioxidant System in Immune Microenvironments.

Achieving bacterial killing and osteogenic formation on an implant surface rarely occurs. In this study, a novel surface design-a palladium hydride (PdHx) film that enables these two distinct features to coexist is introduced. The PdHx lattice captures protons in the extracellular microenvironment of bacteria, disrupting their normal metabolic activities, such as ATP synthesis, nutrient co-transport, and oxidative stress. This disruption leads to significant bacterial death, as evidenced by RNA sequence analysis. Additionally, the unique enzymatic activity and hydrogen-loading properties of PdHx activate the human antioxidant system, resulting in the rapid clearance of reactive oxygen species. This process reshapes the osteogenic immune microenvironment, promoting accelerated osteogenesis. These findings reveal that the downregulation of the NOD-like receptor signaling pathway is critical for activating immune cells toward M2 phenotype polarization. This novel surface design provides new strategies for modifying implant coatings to simultaneously prevent bacterial infection, reduce inflammation, and enhance tissue regeneration, making it a noteworthy contribution to the field of advanced materials.