High Redox Potential Research Articles

Engineering S-scheme mCN@mPDIP molecular heterojunction with highly efficient interface charge transfer for photocatalytic aerobic oxidation synthesis

The construction of S-scheme heterojunctions, which offers a promising approach for spatially separating photogenerated charge carriers with high redox potentials and multimolecular activation, represents a viable modification strategy in photocatalytic applications. However, the prevalent insufficient contact areas between two components result in low interface charge transfer efficiency, thereby impeding the photocatalytic performance of such heterostructures. Herein, we address this limitation by introducing a unique mCN@mPDIP molecular heterojunction through a pH-triggered molecule self-assembly eutectoid technique, enabling intimate interface contact and promoting highly efficient interfacial charge transfer following an S-scheme mechanism. Consequently, the mCN@mPDIP molecular heterojunction achieves significantly improved charge separation efficiency and higher concentration of active carriers compared to typical bCN-bPDIP bulk heterojunction and nCN/nPDIP nano heterojunction. Combined with the effective sulfide activation on mPDIP sites and O2 activation on mCN sites, the resulting mCN@mPDIP demonstrates outstanding activity in the photocatalytic aerobic oxidation of sulfides into sulfoxides without any redox mediators.

Constructing Three-Dimensional Architectures to Design Advanced Copper-Based Current Collector Materials for Alkali Metal Batteries: From Nanoscale to Microscale.

Alkali metals (Li, Na, and K) are deemed as the ideal anode materials for next-generation high-energy-density batteries because of their high theoretical specific capacity and low redox potentials. However, alkali metal anodes (AMAs) still face some challenges hindering their further applications, including uncontrollable dendrite growth and unstable solid electrolyte interphase during cycling, resulting in low Coulombic efficiency and inferior cycling performance. In this regard, designing 3D current collectors as hosts for AMAs is one of the most effective ways to address the above-mentioned problems, because their sufficient space could accommodate AMAs' volume expansion, and their high specific surface area could lower the local current density, leading to the uniform deposition of alkali metals. Herein, we review recent progress on the application of 3D Cu-based current collectors in stable and dendrite-free AMAs. The most widely used modification methods of 3D Cu-based current collectors are summarized. Furthermore, the relationships among methods of modification, structure and composition, and the electrochemical properties of AMAs using Cu-based current collectors, are systematically discussed. Finally, the challenges and prospects for future study and applications of Cu-based current collectors in high-performance alkali metal batteries are proposed.

Revealing Roles of High-Electronegativity Fluorine Atoms in Boosting Redox Potential of Layered Sodium Cathodes.

The development of high-energy-density cathode materials is regarded as the ultimate goal of alkali metal-ion batteries energy storage. However, the strategy of regulating specific capacity is limited by the theoretical capacity, and meanwhile focusing on improving capacity will lead to structural destructions. Herein, a novel perspective is proposed that tuning the electronic band structure by introducing highly electronegative fluoride atoms in NaxTMO2-yFy (0 < x < 1, 0 < y < 2) model compounds to improve redox potential for developing high-energy-density layered oxides. Highly electronegative fluoride atoms is introduced into P2-type Na0.67Fe0.5Mn0.5O2 (NFM), and the thus fluoride NFM (F-NFM) cathode achieved high redox potential (3.0V) and high energy density (446Whkg-1). Proved by structural characterizations, fluorine atoms are successfully incorporated into oxygen sites in NFM lattice. Ultraviolet photoelectron spectroscopy is applied to quantitatively analyze the improved redox potential of F-NFM, which is achieved by the decreased valence band energy in electronic band structure due to the strongly electrophilic fluoride ions. Moreover, fluoride atoms can stabilize the local environment of NFM and improve its redox potential. The work provides a perspective to improve redox potential by tuning the electronic band structure in layered oxides and developing high-energy-density alkali metal-ion batteries.

Polyaniline-modified amorphous tin-based Prussian blue analogue as cathodes for long-life aqueous zinc ion batteries

Prussian blue analogs (PBAs) have emerged in the field of aqueous zinc ion batteries (AZIBs) owing to their simple synthesis method and three-dimensional open framework structure. Although PBAs have high redox potentials, the unsatisfactory specific capacity and poor electrical conductivity limit their development to some extent. In this work, amorphous tin hexacyanoferrate (SnHCF) and polyaniline (PANI) were combined to form SnHCF/PANI composite. The synergistic effect of the amorphous structure of SnHCF and PANI with good conductivity makes the SnHCF/PANI electrode exhibit excellent redox activity and achieve rapid ion/electron transfer. When used as a cathode in AZIBs, the SnHCF/PANI provides a high specific capacity (136.8 mAh g−1 at 0.5 A g−1) and excellent cycling stability (a discharge specific capacity of 54.3 mAh g−1 after 2500 cycles at 2 A g−1). This work offers a new idea for the development of PBAs-based composites as cathode materials for AZIBs.

Fabrication of SrTiO3 anchored rGO/g-C3N4 photocatalyst for the removal of mixed dye from wastewater: dual photocatalytic mechanism

A metal-free combination of rGO/g-C3N4-coupled SrTiO3 (SRN) ternary nanocomposite prepared via a wet impregnation method for UV–Vis light photocatalytic applications. Various physicochemical properties of the samples were investigated by several spectroscopic techniques including X-ray diffraction (XRD), FT-IR, Raman, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM-EDX), high-resolution transmission electron microscopy (HR-TEM), UV–Vis, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) surface area analysis. The data suggest agglomerated SRT nanoparticles are dispersed and distributed throughout the surface of the rGO sheets and GCN nanostructures. The photocatalytic performance of the SRN towards combined mixed dye and its degradation activities were evaluated towards the most common industrial effluents, Rhodamine B (RhB) and Methylene blue (MB), under UV–Vis light illumination. The results revealed that the degradation efficiency of the SRN photocatalyst shows excellent performance compared with that of the binary composition and the pure SrTiO3 (SRT) sample. The reaction rate constant for RhB was estimated to be 0.0039 min−1 and for MB to be 0.0316 min−1, which are 3.26 (RhB) and 4.21 (MB) times faster than the pure SRT sample. The enhanced degradation efficiency was attained not only by interfacial formation but also by the speedy transportation of electrons across the heterojunction. After 5 runs of the photocatalytic recylic process, the SRN photocatalyst exhibited ultimate stability without structural changes, and no noticeable degradation was observed. The outcomes of the ternary SRN nanocomposite manifest a dual photocatalytic scheme, the photocatalytic enrichment could be caused by the Z-scheme charge transfer process between GCN, SRT, and rGO nanocomposite, which helps effectual charge separation and keeps a high redox potential. From the results, SRN sample provides insight into the integration of an effective and potential photocatalyst for wastewater treatment toward real-time environmental remediation applications.

Assembling-induced redox property adjustment of Fe(III)/Fe(IV) electroredox couple-based commercial dye catholyte via bio-inspired multicoordination sphere construction strategy for stable aqueous redox flow batteries

Redox flow batteries (RFBs) are capable of storing and integrating indirect clean energy. This is due to their scalability, safety, and reliability, as well as their independent decoupling of power and energy. Aqueous organic redox flow batteries (AORFBs) have redox-active materials that are composed of abundant elements, have tunable redox potential, greater solubility, and lower cost. Here We propose the use of an inexpensive commercial dye, naphthol green B (NGB), as a catholyte material for AORFBs. This is the first time that NGB has been utilized in the Fe(III)/Fe(IV) electroredox couple, demonstrating a high redox potential of 0.73 V vs. NHE under neutral conditions. Experimental characterizations and theoretical simulations indicate that hydroxypropyl-β-cyclodextrin (HP-β-CD) can serve as the secondary and outer coordination sphere of NGB, enhancing its electrochemical performance and stability, while also preventing transmembrane crossover. In the NGB/K3Fe(CN)6 test with HP-β-CD symmetric battery, NGB demonstrated excellent electrochemical stability. When used as anolyte with 1,1′-bis(3-sulfonatopropyl)-4,4′-bipyridinium (Spr)2V, the NGB/(Spr)2V AORFB with HP-β-CD demonstrated exceptional cycling performance at current rates ranging from 5 to 30 mA cm−2. It is worth noting that the NGB/(Spr)2V AORFB maintained over 99 % of its total capacity or experienced less than 0.00125 % capacity decay per cycle, with an average Coulombic efficiency of almost 100 % over 800 cycles at 10 mA cm−2. NGB is a novel and superior catholyte that offers multiple options for studying AORFBs and the potential for large-scale energy storage applications.

Mechanisms of conjugative transfer of antibiotic resistance genes induced by extracellular polymeric substances: Insights into molecular diversities and electron transfer properties

Dissemination of antibiotic resistance genes (ARGs) has become a critical threat to public health. Activated sludge, rich in extracellular polymeric substances (EPS), is an important pool of ARGs. In this study, mechanisms of conjugation transfer of ARGs induced by EPS, including tightly bound EPS (TBEPS), soluble EPS (SEPS), and loosely bound EPS (LBEPS), were explored in terms of molecular diversities and electron transfer properties of EPS. Conjugation transfer frequency was increased by 9.98-folds (SEPS), 4.21-folds (LBEPS), and 15.75-folds (TBEPS) versus the control, respectively. Conjugation-related core genes involving SOS responses (9 genes), membrane permeability (18 genes), intercellular contact (17 genes), and energy metabolism pathways (13 genes) were all upregulated, especially in the presence of TBEPS. Carbohydrates and aliphatic substances in SEPS and LBEPS were contributors to ARG transfer, via influencing reactive oxygen species (ROS) formation (SEPS) and ROS and adenosine triphosphate (ATP) production (LBEPS). TBEPS had the highest redox potential and greatest lability and facilitated electron transfer and alternated respiration between cells, thus promoting ARG transfer by producing ATP. Generally, the chemical molecular characteristics and redox properties of EPS facilitated ARG transfer mainly by influencing lipid peroxidation and ATP, respectively.

LiF-Rich Alloy-Doped SEI Enabling Ultra-Stable and High-Rate Li Metal Anode.

Li metal is regarded as the "Holy Grail" in the next generation of anode materials due to its high theoretical capacity and low redox potential. However, sluggish Li ions interfacial transport kinetics and uncontrollable Li dendrites growth limit practical application of the energy storage system in high-power device. Herein, separators are modified by the addition of a coating, which spontaneously grafts onto the Li anode interface for in situ lithiation. The resultant alloy possessing of strong electron-donating property promotes the decomposition of lithium bistrifluoromethane sulfonimide in the electrolyte to form a LiF-rich alloy-doped solid electrolyte interface (SEI) layer. High ionic alloy solid solution diffusivity and electric field dispersion modulation accelerate Li ions transport and uniform stripping/plating, resulting in a high-power dendrite-free Li metal anode interface. Surprisingly, the formulated SEI layer achieves an ultra-long cycle life of over 8000 h (20,000 cycles) for symmetric cells at a current density of 10 mA cm-2. It also ensures that the NCM(811)//PP@Au//Li full cell at ultra-high currents (40 C) completes the charging/discharging process in only 68 s to provide high capacity of 151 mAh g-1. The results confirm that this scalable strategy has great development potential in realizing high power dendrite-free Li metal anode.

LiF‐Rich Alloy‐Doped SEI Enabling Ultra‐Stable and High‐Rate Li Metal Anode

AbstractLi metal is regarded as the “Holy Grail” in the next generation of anode materials due to its high theoretical capacity and low redox potential. However, sluggish Li ions interfacial transport kinetics and uncontrollable Li dendrites growth limit practical application of the energy storage system in high‐power device. Herein, separators are modified by the addition of a coating, which spontaneously grafts onto the Li anode interface for in situ lithiation. The resultant alloy possessing of strong electron‐donating property promotes the decomposition of lithium bistrifluoromethane sulfonimide in the electrolyte to form a LiF‐rich alloy‐doped solid electrolyte interface (SEI) layer. High ionic alloy solid solution diffusivity and electric field dispersion modulation accelerate Li ions transport and uniform stripping/plating, resulting in a high‐power dendrite‐free Li metal anode interface. Surprisingly, the formulated SEI layer achieves an ultra‐long cycle life of over 8000 h (20,000 cycles) for symmetric cells at a current density of 10 mA cm−2. It also ensures that the NCM(811)//PP@Au//Li full cell at ultra‐high currents (40 C) completes the charging/discharging process in only 68 s to provide high capacity of 151 mAh g−1. The results confirm that this scalable strategy has great development potential in realizing high power dendrite‐free Li metal anode.

Improved peracetic acid activation under simulated solar-light irradiation by regulating shells of Cu2O: In-situ photothermal activation

Advanced oxidation processes based on light-mediated peracetic acid (PAA) activation are novel degradation systems for wastewater purification. In this work, different shells of Cu2O are controllably synthesized and used to activate PAA under simulative solar light. Interestingly, the kobs in the system without temperature control is 2.47 times that in the temperature-controlled system, implying the important role of the photothermal conversion effect in PAA activation. Reactive oxygen species identification demonstrates that photothermal promotes the decomposition of PAA into radical OH with higher redox potential instead of R–O, which together with non-radical 1O2 achieves a high mineralization rate (72.49%). The core–shell structure enhances light absorption and photogenerated charge separation of Cu2O, thereby improving photothermal conversion efficiency. Meantime, the in-situ photothermal conversion effect expedites the diffusion of ROS and the cycle of active Cu(Ⅱ)/Cu(Ⅰ) ultimately achieves the high-efficiency and long-lasting PAA activation. This work provides novel strategies for solar energy utilization and PAA activation processes in wastewater purification.

Epitaxial growth of Bi4Ti3O12-BiPO4 Z-scheme heterojunction to promote carrier transfer for photocatalytic oxidation of NO

The lack of compactness in heterojunction interfaces and poor charge separation is a great challenge in developing high-efficiency heterojunction photocatalysts. Herein, a novel Bi4Ti3O12-BiPO4 heterojunction was successfully prepared for the first time by epitaxial growth of BiPO4 on the surface of Bi4Ti3O12 nanosheets. The optimized Bi4Ti3O12-BiPO4-0.5 increased the NO oxidation efficiency to 73.05%, surpassing pure Bi4Ti3O12 (63.45%) and BiPO4 (8.35%). Experiments and theoretical calculations indicated that the closely contacted heterointerface between BTO and BPO promoted the generation of the built-in electric field, which led to the formation of the Z- scheme transfer pathway for the photogenerated carriers. Therefore, the separation of photogenerated carriers was facilitated while retaining high redox potential, generating more ·O2– and ·OH to participate in NO oxidation. Furthermore, the adsorption of NO and O2 was enhanced by introducing BiPO4, further improving the photocatalytic NO oxidation performance. This work emphasizes the critical role of heterointerface in accelerating charge transfer, providing a basis for the design and construction of tightly contacted heterojunction photocatalysts.

P-016 Prevalence of high oxidative stress and poor sperm DNA fragmentation levels in different groups of patients

Abstract Study question What is the prevalence of patients with high oxidation-reduction potential (ORP) and high sperm DNA fragmentation (SDF) in different patient groups with and without varicocele? Summary answer A large percentage of normozoospermic patients and patients who are normally considered of manageable in assisted reproduction show high SDF and/or high ORP. What is known already Standard semen analysis, even according to WHO criteria, is very limited in predicting male fertility potential. Oxidative stress is widely recognized as a major contributor to male infertility. Therefore, sperm DNA fragmentation (SDF) is increasingly recommended as additional test in diagnostics. High levels of oxidative stress and SDF have also been reported in patients with varicocele. Yet, SDF and oxidative stress tests are not routinely tested in ART laboratories. Apart from the cost and/or complexity of these tests, a reason for the lack of usage is the lack of knowledge of the prevalence. Study design, size, duration This is a retrospective analysis of data obtained from 2,946 patients attending the Department of Urology, Hamad Medical Corporation, Doha, Qatar, for fertility diagnosis from January to December 2018. For this analysis only patients (n = 773) who had a full data set for sperm DNA fragmentation (SDF) and seminal oxidative stress as measured by means of the oxidation-reduction potential (ORP) were included. Participants/materials, setting, methods Apart from SDF and ORP, standard semen parameters (ejaculate volume, sperm concentration, total and progressive motility, and normal sperm morphology), and the presence of varicocele were determined. Semen parameters were determined according to WHO 2010 criteria. SDF was tested using the Halosperm G2 test (Halotech DNA SL, Madrid, Spain), while ORP was determined using the MiOXSYS® (Aytu BioScience, Englewood, CO). Patients were categorized as normo-, oligo-, astheno-, and teratozoospermic. Main results and the role of chance The mean sperm concentration of the patients was 33.5 × 106 sperm/mL with a mean total motility of 50.3%. The overall percentage of patients with high (&amp;gt;20% SDF) SDF was 57.4% and those with high (≥1.34 mV/106 sperm/mL) ORP 63.4%. Varicocele was diagnosed in 14.0% of the patients. In normozoospermic patients, 26.8% had high SDF, whereas in the non-normozoospermic group this was 59.8% (P = 0.0108). In non-oligozoospermic (53.7%), non-asthenozoospermic (34.7%) and non-teratozoospermic (43.4%) groups, SDF was significantly higher. High ORP values were recorded in 35.7% of normozoospermic, 53.4% non-oligozoospermic, 47.2% of non-asthenozoospermic, and 49.7% of teratozoospermic patients. The difference between the prevalence of high ORP in the normozoospermic (35.7%) and the non-normozoospermic group is significant (P = 0.0063). When both tests (high SDF or high ORP) were considered, 50.0% of normozoospermic, 76.9% of non-oligozoospermic, 59.7% of non-asthenozoospermic, and 71.2% of non-teratozoospermic patients showed seminal pathology. High SDF was detected in 59.3% of varicocele patients, while 50.0% of varicocele patients had high ORP values. In patients without varicocele, 57.1%, 65.6%, and 82.7% had high SDF, high ORP, and high SDF or high ORP, respectively. These percentages were significantly (P &amp;lt; 0.0003) higher than for the corresponding normal groups. Limitations, reasons for caution Although the overall sample size of 773 is reasonably high, after sub-grouping the sample size is much smaller. Since this study only analyzed the SDF and ORP in patients attending and andrological outpatient clinic, the results could be different if patients in IVF and/or ICSI treatment cycles were analyzed. Wider implications of the findings This study highlights that complementation of semen analysis with SDF and oxidative stress testing will identify a large percentage of patients who would benefit from andrological treatment before assisted reproductive techniques (ART). This approach would result in better chances of these patients for successful ART. Trial registration number not applicable

Omeprazole-Loaded Copper Nanoparticles for Mitochondrial Damage Mediated Synergistic Anticancer Activity against Melanoma Cells.

Metallic nanoparticles are promising candidates for anticancer therapies. Among the different metallic systems studied, copper is an affordable and biologically available metal with a high redox potential. Copper-based nanoparticles are widely used in anticancer studies owing to their ability to react with intracellular glutathione (GSH) to induce a Fenton-like reaction. However, considering the high metastatic potential and versatility of the tumor microenvironment, modalities with a single therapeutic agent may not be effective. Hence, to enhance the efficiency of chemotherapeutic drugs, repurposing them or conjugating them with other modalities is essential. Omeprazole is an FDA-approved proton pump inhibitor used in clinics for the treatment of ulcers. Omeprazole has also been studied for its ability to sensitize cancer cells to chemotherapy and induce apoptosis. Herein, we report a nanosystem comprising of copper nanoparticles encapsulating omeprazole (CuOzL) against B16 melanoma cells. The developed nanoformulation exerted significant synergistic anticancer activity when compared with either copper nanoparticles or omeprazole alone by inducing cell death through excessive ROS generation and subsequent mitochondrial damage.

Dual modification of current collector for high-performance lithium metal batteries by laser etching

Despite the lithium metal anode is regarded as the next generation of anode for its high energy density and low redox potential, the huge volume expansion and high reactivity between lithium and electrolyte still limit its application. Herein, a multilayer Cu current collector is designed to accommodate the volume expansion and suppress the high reactivity. Through laser etching, the structure and the chemical component of Cu foil are deeply changed. Planar Cu is etched to construct regular microstructure with different length in interval, which regulate the current density distribution and alleviate the massive volume expansion during the charging process. And the surface of microstructure reacts with air to form lithiophilic phase CuxO layer in situ resulting in stable surface of lithium metal anodes. The simple dual-modification strategy enables the half-cell to achieves a cycle life of over 240 cycles with the CE above 98%. In contrast, the initial Cu only achieve a cycle life of less than 50 cycles. Meanwhile, full battery based on multilayer current collector delivered outstanding cycle stability. This work shows an innovative sight for the modification of current collector and safe Li metal anode.

Poly(PROXYL−Methacrylate) Polymer for High Redox Potential Organic Electrodes

AbstractRadical polymers are actively being investigated in different applications such as batteries. In order to store higher energy, radical polymers with high redox potential are searched. This work describes the synthesis of 2,2,5,5‐tetramethylpyrrolin−N−oxyl methacrylate monomer (PROXYL−methacrylate) and its polymerization to get a PolyPROXYL−methacrylate (PPMA) by free radical polymerization. The structures of the monomer and the percentage of redox active groups of the polymer were determined by mean of NMR and UV‐Vis spectroscopy, respectively. Cyclic voltammetry of the novel redox polymer revealed a half‐wave potential (E1/2) of 3.7 V vs Li+/Li stable at different scan rates, which was ascribed to the efficient swelling and insoluble properties of PPMA. The polyPROXYL−methacrylate polymer exhibits higher nominal redox potential than the reference radical polymer polyTEMPO−methacrylate (PTMA). Li−metal lab‐scale cells fabricated with the PPMA cathode active material performed at different C‐rates (up to 50 C) with reversible charge/discharge and a specific capacity output of 80 mAh g−1 at 1 C, along with 96 % capacity retention after more than 100 cycles. Finally, the comparison between PPMA and PTMA redox polymers evidenced the superior performances of the PROXYL with respect to TEMPO in terms of energy density and half‐wave potential.

Analytical fingerprint of the interactions between quinones and bioenergetic membranes in Chlamydomonas reinhardtii

The use of intact photosynthetic organisms (e.g. microalgae or cyanobacteria) for biotechnological approaches is a promising avenue to extract sustainable energy from oxygenic photosynthesis. More particularly, exogenous quinones can act as electron shuttles to reroute part of the photosynthetic electron flow of living cells to an outer collecting electrode. This encouraging approach is however hampered by reported poisoning or side-effects of exogenous quinones on the cell bioenergetics. In order to contribute to understand those effects, we investigated the modes and sites of interaction of two model quinones (2,6-DCBQ and 2,6-DMBQ) with the respiratory and photosynthetic electron transfer chains of the green alga Chlamydomonas reinhardtii. By considering different analytical tools (chlorophyll a fluorescence, transient absorption spectrometry, O2 consumption rate), the two exogenous quinones are shown to hamper the photosynthetic electron transfer from photosystem II (PSII) to the cytochrome b6f and, at longer term, PSII damage. In addition, the investigated quinones initiate the suppression of mitochondrial respiration, illustrated by the decrease of O2 consumption. This results in the diminution of the ATP exchanges between mitochondrion and chloroplast responsible for the generation of the proton motive force across the thylakoid in darkness, and in turn affects the performances of the CF1FO ATPase. For all those effects, 2,6-DCBQ was more effective than 2,6-DMBQ in agreement with its higher redox potential and partition coefficient values. This work provides a new framework for the study of biophotovoltaic devices using photosynthetic organisms and quinones as mediators and could be extended to find the best candidates combining efficient bioelectricity production and limited toxicity.

Inhibiting the Jahn-Teller Effect of Manganese Hexacyanoferrate via Ni and Cu Codoping for Advanced Sodium-Ion Batteries.

Manganese (Mn)-based Prussian blue analogs (PBAs) are of great interest as a prospective cathode material for sodium-ion batteries (SIBs) due to their high redox potential, easy synthesis, and low cost. However, the Jahn-Teller effect and low electrical conductivity of Mn-based PBA cause poor structure stability and unsatisfactory performance during the cycling. Herein, a novel nickel- and copper-codoped K2Mn[Fe(CN)6] cathode is developed via a simple coprecipitation strategy. The doping elements improve the electrical conductivity of Mn-based PBA by reducing the bandgap, as well as suppress the Jahn-Teller effect by stabilizing the framework, as verified by the density functional theory calculations. Simultaneously, the substitution of sodium with potassium in the lattice is beneficial for filling vacancies in the PBA framework, leading to higher average operating voltages and superior structural stability. As a result, the as-prepared Mn-based cathode exhibits excellent reversible capacity (116.0 mAh g-1 at 0.01 A g-1) and superior cycling stability (81.8% capacity retention over 500 cycles at 0.1 A g-1). This work provides a profitable doping strategy to inhibit the Jahn-Teller structural deformation for designing stable cathode material of SIBs.

Interfacial modulation of bifunctional electrolyte additive engineering for dendrite-free and robust lithium metal anode

Anode materials for rechargeable electric car batteries are obtained from Li-metal owing to their extremely high specific capacity and low redox potential. Unfortunately, safety concerns related to dendrite formation on the anode surface caused by the uneven distribution of Li-ions during the discharge process interfere with the use of Li-metal in industrial batteries. In this study, methyl vinyl sulfone (MVS), a sulfone-based functional electrolyte additive, is used in an additive engineering strategy to control Li-electrolyte interactions and address the aforementioned problems. Li dendrite growth may be restricted, and transition metal degradation on the surface of the cathode can be reduced by the MVS-derived functional electrolyte additive interfacial layer. The electrochemical performance of an ethylene carbonate/dimethyl carbonate (EC/DMC) + 1 wt% MVS Li-metal anode of a Li||Li symmetric cell exhibits remarkable cycle stability, maintaining a low overvoltage for over 750 h at 1 mA cm−2, and capacity of 1 mA h cm−2. Additionally, LiNi0.8Co0.1Mn0.1O2 (NCM811) full cells with the MVS additive exhibit enhanced electrochemical stability for 250 cycles at a current density of 100 mA g−1. This study provides an innovative approach for stabilizing the metal-electrolyte interfacial layer that may be used for practical applications in metal-based rechargeable batteries.

Efficient photocatalytic reforming of cellulose for H2 production enabled by oxygen-vacancy rich SrMoO4/palygorskite nanocomposite

Photocatalytic reforming of biomass into hydrogen along with the simultaneous production of high-value chemicals, plays a significant role in advancing a sustainable economy. A major challenge in this process is the effective utilization of photogenerated holes while simultaneously preventing the rapid recombination of photoinduced carriers, which is crucial for optimizing solar-to-hydrogen conversion efficiency. In this study, an exquisite oxygen-rich vacancy (OV) plasmonic SrMoO4/phosphor acidized palygorskite (H-Pal) nanocomposite was prepared for efficient photocatalytic H2 evolution while producing high value-added lactic acid (LA) simultaneously. Results showed that the integration of local surface plasmon resonance (LSPR) effect and OV enhanced the photothermal catalytic conversion of cellulose reaching as high as 87%. Notably, the selectivity of LA reached as high as 31% while the H2-evolution efficiency reached 906 μmol•g-1•h-1. The local thermal effect improved the conversion efficiency of cellulose, and the OV in SrMoO4 introduced instantaneous Lewis acid sites during light irradiation, which improved the selectivity for LA. Moreover, the formation of an S-scheme SrMoO4-OV/H-Pal heterostructure effectively inhibited the recombination of photogenerated electron-hole pairs and maintained a high redox potential. This work demonstrates a promising strategy for efficient photocatalytic H2-evolution, coupled with production of high-valuable chemicals from biomass resources by taking advantage of clay materials.

Tautomeric pillars in vanadyl phosphate cathode to screen the divalent charge on Zn2+ for aqueous Zn batteries

Cathode materials with high redox potential are important for constructing high-energy-density aqueous zinc batteries. The polyanion compound of layered hydrate vanadyl phosphate (H2O-VOP) provides high potential thanks to the inductive effect. However, the sluggish Zn2+ diffusion in the lattice results in large voltage hysteresis, obstructing the capacity release at high voltage. Herein, tautomeric pillars are inserted in the VOPO4 layers (Tau-VOP) by the desulfhydryl reaction of l-cysteine, aiming to suppress voltage hysteresis with their charge screening effect. Specifically, the Lewis alkaline sites on the tautomers capture inserted Zn2+, and the divalent charge is further delocalized over the conjugated structure of pillars. This reduction of effective charge on cations ensures much weakened electrostatic interactions with the lattice and reduced diffusion barrier. As a result, the Tau-VOP cathode achieves 193 mAh g−1 capacity with 1.47 V/1.6 V redox voltage in zinc cells, which are superior to 110 mAh g−1 capacity and 1.1 V average discharge voltage with large voltage hysteresis obtained with H2O-VOP. The rate performance and energy efficiency are also significantly improved with the help of tautomer pillars. This work presents an effective charge screening strategy by suitable pillars to facilitate multivalent cation transport in cathode structures and enhance electrochemical performance.