Oxide Oxygen Research Articles

C-Peptide Ameliorates Particulate Matter 2.5-Induced Skin Cell Apoptosis by Inhibiting NADPH Oxidation.

Connecting peptide (C-peptide), a byproduct of insulin biosynthesis, has diverse cellular and biological functions. Particulate matter 2.5 (PM2.5) adversely affects human skin, leading to skin thickening, wrinkle formation, skin aging, and inflammation. This study aimed to investigate the protective effects of C-peptide against PM2.5-induced damage to skin cells, focusing on oxidative stress as a key mechanism. C-peptide mitigated NADPH oxidation and intracellular reactive oxygen species (ROS) production induced by PM2.5. It also suppressed PM2.5-induced NADPH oxidase (NOX) activity and alleviated PM2.5-induced NOX1 and NOX4 expression. C-peptide protected against PM2.5-induced DNA damage, lipid peroxidation, and protein carbonylation. Additionally, C-peptide mitigated PM2.5-induced apoptosis by inhibiting intracellular ROS production. In summary, our findings suggest that C-peptide mitigates PM2.5-induced apoptosis in human HaCaT keratinocytes by inhibiting intracellular ROS production and NOX activity.

Metformin in Antiviral Therapy: Evidence and Perspectives

Metformin, a widely used antidiabetic medication, has emerged as a promising broad-spectrum antiviral agent due to its ability to modulate cellular pathways essential for viral replication. By activating AMPK, metformin depletes cellular energy reserves that viruses rely on, effectively limiting the replication of pathogens such as influenza, HIV, SARS-CoV-2, HBV, and HCV. Its role in inhibiting the mTOR pathway, crucial for viral protein synthesis and reactivation, is particularly significant in managing infections caused by HIV, CMV, and EBV. Furthermore, metformin reduces oxidative stress and reactive oxygen species (ROS), which are critical for replicating arboviruses such as Zika and dengue. The drug also regulates immune responses, cellular differentiation, and inflammation, disrupting the life cycle of HPV and potentially other viruses. These diverse mechanisms suppress viral replication, enhance immune system functionality, and contribute to better clinical outcomes. This multifaceted approach highlights metformin’s potential as an adjunctive therapy in treating a wide range of viral infections.

Structural Stabilization of 4.6V LiCoO2 Through Tri-Site Co-Doping with Al-Mg-F.

Uplifting the charging voltage of LiCoO2 is crucial for surpassing current energy density thresholds in Li-ion batteries. However, the structural and chemical instability of LiCoO2 in the deeply delithiated state is a major obstacle to the practical implementation of high-voltage LiCoO2. This study proposes a multi-element co-doped LiCoO2 that exhibits enhanced electrochemical performances at 4.6V (vs Li/Li+). Al, Mg, and F are doped at three distinct lattice sites, and the contributions of each dopant are investigated using advanced synchrotron X-ray analyses and electron microscopies. Al and Mg delay the detrimental transition to the H1-3 phase and facilitate a smoother phase transition, thereby preserving particle robustness. The electronegative anion dopant F mitigates oxygen oxidation and ensures a wider range of transition metal redox reactions. These enhancements enable the particles to withstand numerous cycles without severe cracking or surface degradation, thereby significantly improving cyclability. Consequently, the tri-site doping strategy effectively minimizes capacity sacrifice and bolsters battery performance, with every dopant functioning synergistically.

Chemical Competing Diffusion for Practical All-Solid-State Batteries.

The thermal safety issues of currently available Ni-rich cathode-based power supplies brought in the development of all-solid-state batteries, yet the cascade reactions in Ni-rich materials and the chemo-mechanical degradation between the cathode and solid electrolyte diminished the cycle life. Here, by introducing a new heteroatom chemical competing diffusion strategy, we successfully stabilize the Ni-rich cathode and the contact face with an solid electrolyte. Combining extensive explorations in theoretical calculation and multiscale in/ex situ characterization, we elucidate the atomic-level chemical competing diffusion upon the topological lithiation of layered materials. The heteroatoms with higher binding energy to the coordinated oxygen served as the "oxygen anchor" in the bulk and alleviated the excessive oxygen oxidation through charge compensation, thus easing the chemical aggression of the solid electrolyte by evolved oxygen. Comparably, others were enriched in the surface and formed an ionic "diffusion regulator" with residual lithium, and the special ionic transfer regulation mechanism of the piezoelectric layer validly improved the interface compatibility with the solid electrolyte and weakened the space-charge layer in solid-state batteries. This helped the designed Ni-rich cathode-based sulfide solid-state battery exhibit excellent cyclability under 4.5 V (97.3% after 120 cycles). Our findings unlocked the structure-function relationship between the polarization field generated by the piezoelectric material and the electrode.

Cooperative Active Sites on Ag2Pt3TiS6 for Enhanced Low‐Temperature Ammonia Fuel Cell Electrocatalysis

AbstractAmmonia has attracted considerable interest as a hydrogen carrier that can help decarbonize global energy networks. Key to realizing this is the development of low temperature ammonia fuel cells for the on‐demand generation of electricity. However, the efficiency of such systems is significantly impaired by the sluggish ammonia oxidation reaction (AOR) and oxygen reduction reaction (ORR). Here, we report the design of a bifunctional Ag2Pt3TiS6 electrocatalyst that facilitates both reactions at mass activities exceeding that of commercial Pt/C. Through comprehensive density functional theory calculations, we identify that active site motifs composed of Pt and Ti atoms work cooperatively to catalyze ORR and AOR. Notably, in situ shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) experiments indicate a decreased propensity for *NOx formation and hence an increased resistance toward catalyst poisoning for AOR. Employing Ag2Pt3TiS6 as both the cathode and anode, we constructed a low temperature ammonia fuel cell with a high peak power density of 8.71 mW cm−2 and low Pt loading of 0.45 mg cm−2. Our findings demonstrate a pathway towards the rational design of effective electrocatalysts with multi‐element active sites that work cooperatively.

Hydrogen Sulphide: A Key Player in Plant Development and Stress Resilience.

Based on the research conducted so far, hydrogen sulphide (H2S) plays a crucial role in the development and stress resilience of plants. H2S, which acts as a signalling molecule, responds to different stresses such as heavy metals, drought, and salinity, and it regulates various aspects of plant growth and development including seed germination, root development, stomatal movement, flowering, and fruit ripening. Additionally, H2S is involved in mediating legume-Rhizobium symbiosis signalling. It modulates plant responses to external environmental stimuli by interacting with other signalling molecules like phytohormones, nitric oxide, and reactive oxygen species. Furthermore, H2S exerts these regulations since it can modify protein functions through a reversible thiol-based oxidative posttranslational modification called persulfidation, particularly in stress response and developmental processes. As a result, H2S is recognised as an important emerging signalling molecule with multiple roles in plants. Research in this field holds promise for engineering stress tolerance in crops and may lead to potential biotechnological applications in agriculture and environmental management.

Modulating Metal Activation Energy via Cerium-Mediated Heterointerface Defect Evolution for Photovoltaic-Driven Efficient Water Electrolysis

Exploring electrocatalysts with high-valence metal sites is crucial to accelerate oxygen evolution reaction (OER), yet it encounters challenges arising from thermodynamic formation barriers. We have in-situ constructed a multi-defective Ce³⁺-Ov-M active interface through a dynamic interface defect integration strategy, regulating the ionic conductivity and the formation barrier of high-valence Ni and achieving an ultralow overpotential of 155mV at 10mAcm-2 current density for OER. The recordings from in-situ Raman and UV-Vis spectroscopy illustrate that the modulated catalyst facilitates a cathodic shift in the transition potential for forming γ-NiOOH. Theoretical calculations have confirmed the mechanism, indicating that defect-engineering at the heterointerface leads to electron localization, lower d-band centers enhance the electron distribution at metal active centers, and activate lattice oxygen for efficient water oxidation. This property extended to hydrogen evolution catalysts also exhibits high versatility. Perovskite/crystalline silicon tandem solar cells are used to drive the electrolytic assembly system to achieve 21.01% solar hydrogen conversion efficiency.

Influence of atomic coordination on the activity of lattice oxygen and catalytic oxidation of toluene over regular Cu2O crystalline

VOCs oxidation over transition metal catalyst is commonly understood via the Mars-van Krevelen mechanism involving the crucial role of lattice oxygen (OL) activity, however, how it is influenced by atomic coordination is still unclear. Herein, we use model catalysts of Cu2O-cub, Cu2O-oct and Cu2O-dod with crystal planes of (100), (111) and (110), respectively, to investigate the OL activity and catalytic oxidation of toluene. The activity of Cu2O-oct is found to be the highest, followed by Cu2O-cub and Cu2O-dod. Experiments results combined with density functional theory show that, although low di-coordinated O atoms leads to the lowest surface oxygen vacancy formation energy (2.47eV) and the highest surface OL activity of Cu2O-cub, it cannot determine the activity. The lowest bulk oxygen vacancy formation energy (3.16eV) in Cu2O-oct terminated with tri-coordinated O atoms and open surface can accelerate the migration and replenishment of OL, thereby promoting the catalytic activity.

Structure elucidation and molecular mechanism of an immunomodulatory polysaccharide from Nostoc commune

Nostoc commune Vaucher, a terrestrial and benthic blue-green alga, widely used in food and medicine worldwide. N. commune Polysaccharides (NCVP) have excellent biological activities, especially immunomodulatory, hypoglycemic and anti-tumor activities. However, the mechanism and structure-activity relationship of NCVP has been less studied. In this study, based on methylation and NMR results, a novel polysaccharide NCVP2 with 135 kDa, containing→4)-α-D-Galp-(1→, → 4)-β-D-Glcp-(1→, and →4)-α-D-Xylp-(1→ residues as the backbon, was sequentially purified from N.commune by DEAE-52 and Sephadex G-100 column. NCVP2 (50 μg/mL) exhibited the strong in vitro immunomodulatory activity by promoting the generation of nitric oxide (NO) and reactive oxygen species (ROS). A total of 2048 differentially expressed genes (DEGs) were identified by RNA-seq, including 1019 down-regulated genes and 1065 up-regulated genes. These DEGs were mainly enriched in the immune-related biological processes, involving in Mitogen-activated protein kinase (MAPK) and Toll-like receptor (TLR) signaling pathways by GO and KEGG enrichment analysis. Furthermore, Western blot results proved NCVP2 could recognize TLR2 and TLR4/MD2, and regulate TLR7/IRF7, MAPK and PI3K/AKT signaling pathways. In summary, a novel polysaccharide NCVP2 from N.commune was proposed to exhibit significant immunomodulatory effects with multiple-paths and targets, and has great potential in the development of healthy foods such as immunomodulators.

Tuning microenvironment of Bi2O3 nanosheets via Ce doping for promoting CO2 electrolysis to formate

The precise tuning of the electrocatalytic surface microenvironment for CO2 adsorption and conversion is essential for an efficient electrocatalytic CO2 reduction reaction (eCO2RR); however, it constitutes a challenging task. In this work, Ce-doped Bi2O3 nanosheets with enhanced Bi oxidation and abundant oxygen vacancies have been developed as an efficient electrocatalyst for the eCO2RR. The synthesized Ce/Bi2O3 nanosheet electrocatalyst achieves a Faraday efficiency above 90 % for formate production within a wide potential window from −0.8 to −1.1 V (versus RHE). The Ce dopant as an electron acceptor modifies the electronic structure of the Bi sites, enhancing the CO2 adsorption and promoting the formation of CO2•−. Moreover, Ce doping provides a local high pH and accelerates the proton-electron transfer process of *OCHO intermediates. This work provides new insights into the formation of a highly active reaction zone at the gas–liquid–solid interface for establishing a favorable microenvironment and further promoting an efficient eCO2RR.

Zinc ions facilitate metabolic bioenergetic recovery post spinal cord injury by activating microglial mitophagy through the STAT3-FOXO3a-SOD2 pathway

Spinal cord injury (SCI) is a devastating condition of the central nervous system (CNS) with high global rates of disability and mortality, and no effective cure currently available. Microglia play a critical role in the progression of SCI, and enhancing their metabolic function may facilitate tissue repair and recovery. Mitochondrial dysfunction is a key feature of metabolic impairment, with the regulation of autophagy being essential for maintaining mitochondrial homeostasis and cell survival. The transcription factor Forkhead box O3a (FOXO3a) is integral to cellular metabolism, mitochondrial dysfunction, and oxidative stress responses, yet its role in post-SCI microglial metabolism remains underexplored. In this study, single-cell RNA sequencing reveals the crucial involvement of the FOXO signaling pathway in zinc ion-mediated enhancement of microglial metabolism. Mechanistically, oxidative stress-induced reactive oxygen species (ROS) accumulation exacerbates metabolic dysfunction by promoting excessive mitochondrial fission and impairing mitophagy. Importantly, zinc ions induce the nuclear translocation of FOXO3a, leading to its activation as a transcription factor. This activation enhances mitochondrial autophagy and fusion processes, thereby restoring microglial metabolic capacity. Our findings suggest that the zinc ion regulation of the STAT3-FOXO3a-SOD2 axis is pivotal in modulating mitochondrial gene expression, which governs microglial energy homeostasis and improves the spinal cord microenvironment, potentially enhancing neuronal survival. These insights highlight a promising therapeutic target for SCI.

Strategic Design for High-Efficiency Oxygen Evolution Reaction (OER) Catalysts by Triggering Lattice Oxygen Oxidation in Cobalt Spinel Oxides.

High-efficiency catalysts with refined electronic structures are highly desirable for promoting the kinetics of the oxygen evolution reaction (OER) and enhancing catalyst durability. This study comprehensively explores strategies involving metal doping and oxygen vacancies for enhancing the acidic OER catalytic activity of Co3O4. Through extensive screening of 3d and 4d transition metals using density functional theory (DFT) simulations, we demonstrate that the incorporation of metal dopants and oxygen vacancies into Co3O4 potentially triggers a transition from the adsorbate evolution mechanism (AEM) to the lattice oxygen oxidation mechanism (LOM) in the oxygen evolution reaction (OER). While the formation of the O-O bond in the intermediate *OOH poses challenges, a significantly reduced overpotential facilitates efficient conversion of O to O2 through the LOM in *OH and lattice oxygen. Additionally, we find that Mn doping can significantly improve the stability of the catalyst. Building upon the rationale above, we employed a dual doping strategy in subsequent experiments to enhance both the activity and stability. Our final design involved the codoping of Mn and Ru in Co3O4, along with an appropriate amount of oxygen vacancies. This catalyst demonstrates a low overpotential (η10 = 230 mV) compared to pure Co3O4 and maintains stable operation for over 120 h, representing a 12-fold increase. By exploring and harnessing the LOM, more efficient, stable, and cost-effective OER catalysts can be designed, providing crucial support for technologies such as water electrolysis in clean energy.

Redox Control of Seed Germination is Mediated by the Crosstalk of Nitric Oxide and Reactive Oxygen Species.

Significance: Seed germination and seedling establishment are characterized by changes in the intracellular redox state modulated by accelerated production of nitric oxide (NO) and reactive oxygen species (ROS). Redox regulation and enhanced accumulation of NO and ROS, approaching excessively high levels during seed imbibition, are critically important for breaking endodormancy and inducing germination. Recent Advances: Upon depletion of oxygen under the seed coat, NO is produced anaerobically in the reductive pathway associated mainly with mitochondria, and it participates in the energy metabolism of the seed until radicle protrusion. NO turnover involves nitrate reduction to nitrite in the cytosol, nitrite reduction to NO in mitochondria, and NO oxygenation in the cytosol in the reaction involving the hypoxically induced class 1 phytoglobin. In postgerminative degradation of seed tissues, NO and ROS are involved in redox signaling via post-translational modification of proteins and mediation of phytohormonal responses. Critical Issues: The crosstalk between the cellular redox potential, NO, ROS, and phytohormones integrates major physiological processes related to seed germination. Intensive accumulation of NO and ROS during imbibition is critically important for breaking seed dormancy. Upon oxygen depletion, NO and other nitrous oxides (NOx) are produced anaerobically and support energy metabolism prior to radicle protrusion. Future Directions: The turnover of NOx and ROS is determined by the intracellular redox balance, and it self-controls redox and energy levels upon germination. The particular details, regulation of this process, and its physiological significance remain to be established. Antioxid. Redox Signal. 00, 000-000.

Low infrared emissivity and corrosion resistance of TiO2 films prepared by thermal oxidation of sputtered Ti films

To develop low infrared emissivity and corrosion resistant films, a dense rutile TiO2 film was synthesized by thermal oxidizing sputtered Ti metal film under hypoxic environment at 300, 400, 500 and 600℃. Results show that with rising oxidation temperature, surface defects and oxygen vacancies decrease. At 300℃ and 400℃, less oxygen leads to pores. As temperature increases, surface grains become smaller and denser, and films change from hydrophilic to hydrophobic. At 500°C, the TiO2 film with emulsion - like morphology and protrusions has a contact angle of 148.75° (near superhydrophobic), enhancing corrosion resistance. At 600°C, the increase in carrier density reduces resistivity, and the densely packed structure minimizes infrared absorption, achieving a low infrared emissivity of 0.125 in 8–14 μm wavelength range.

Cooperative Active Sites on Ag2Pt3TiS6 for Enhanced Low-Temperature Ammonia Fuel Cell Electrocatalysis.

Ammonia has attracted considerable interest as a hydrogen carrier that can help decarbonize global energy networks. Key to realizing this is the development of low temperature ammonia fuel cells for the on-demand generation of electricity. However, the efficiency of such systems is significantly impaired by the sluggish ammonia oxidation reaction (AOR) and oxygen reduction reaction (ORR). Here, we report the design of a bifunctional Ag2Pt3TiS6 electrocatalyst that facilitates both reactions at mass activities exceeding that of commercial Pt/C. Through comprehensive density functional theory calculations, we identify that active site motifs composed of Pt and Ti atoms work cooperatively to catalyze ORR and AOR. Notably, in situ shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) experiments indicate a decreased propensity for *NOx formation and hence an increased resistance toward catalyst poisoning for AOR. Employing Ag2Pt3TiS6 as both the cathode and anode, we constructed a low temperature ammonia fuel cell with a high peak power density of 8.71 mW cm-2 and low Pt loading of 0.45 mg cm-2. Our findings demonstrate a pathway towards the rational design of effective electrocatalysts with multi-element active sites that work cooperatively.

Oxygen/Nitric Oxide Dual-Releasing Nanozyme for Augmenting TMZ-Mediated Apoptosis and Necrosis.

Glioblastoma multiforme (GBM) is the most common and aggressive malignant brain tumor, with a poor prognosis. Temozolomide (TMZ) represents the standard chemotherapy for GBM but has limited efficacy due to poor targeting and a hypoxic tumor microenvironment (TME). To address these challenges, we developed a dual-gas-releasing, cancer-cell-membrane-camouflaged nanoparticle to deliver TMZ. This nanoceria, camouflaged with a cancer cell membrane (CCM-CeO2), targets explicitly GBM cells and accumulates in lysosomes, triggering the rapid release of TMZ. Additionally, CCM-CeO2 could release oxygen (O2) and nitric oxide (NO) in response to the TME. Synthesized using d-arginine, catalytic nanoceria could decompose excessive hydrogen peroxide (H2O2) in the TME to produce O2, while d-arginine could nonenzymatically react with H2O2 to generate NO. CCM-CeO2 could penetrate GBM spheroids to a depth of 148.3 ± 31 μm, with the O2 and NO produced, reducing HIF-1α protein expression. When loaded with TMZ, CCM-CeO2 could increase the intracellular ROS produced by TMZ, leading to lysosome membrane permeabilization and notably augmented apoptosis and necrosis in GBM cells. An in vitro antitumor assay using spheroids showed that CCM-CeO2 reduced the IC50 value of TMZ from 174.5 to 42.6 μg/mL, likely due to the catalase-like activity of nanoceria. These results suggest that alleviating hypoxia and increasing ROS produced by chemotherapeutics could be an effective therapeutic strategy for treating GBM.

The therapeutic effects of curcumin on polycystic ovary syndrome by upregulating PPAR-γ expression and reducing oxidative stress in a rat model.

Polycystic ovary syndrome (PCOS) is a prevalent endocrine and metabolic disorder that impacts 8-13% of women in their reproductive years. However, the drugs commonly used to treat PCOS are often prescribed off-label and may carry potential side effects. This study aimed to investigate the therapeutic effects of curcumin in a PCOS rat model. A PCOS rat model was established through daily subcutaneous injection of 60 mg/kg body weight of dehydroepiandrosterone (DHEA) for 21 days. The PCOS rats received a daily intragastric dose of 50 mg/kg body weight of curcumin for another 21 days. Ovarian morphological changes, estrous cycle changes, and hormone level changes were measured to evaluate the therapeutic effectiveness of curcumin in PCOS rats. Oxidative stress markers in the ovaries were analyzed to explore the mechanisms of curcumin in PCOS rats. This study demonstrated that curcumin alleviated insulin resistance and significantly reduced serum levels of estradiol (p = 0.02), luteinizing hormone (p = 0.009), testosterone (p = 0.003), and the LH/FSH ratio (p = 0.008) in PCOS rats. Curcumin also restored normal ovarian morphology and the estrous cycle in these rats. Furthermore, curcumin treatment significantly decreased levels of oxidative stress markers, including malondialdehyde (p = 0.004) and reactive oxygen species (p = 0.005), while increasing antioxidant levels such as superoxide dismutase (p = 0.04), glutathione peroxidase (p = 0.002), and glutathione (p = 0.02) in ovarian tissues. Additionally, curcumin significantly upregulated PPAR-γ in the ovarian tissues of PCOS rats. This study demonstrates that curcumin effectively restores ovarian morphology, hormone levels, and estrous cycles in PCOS rats. These effects may be linked to its ability to reduce oxidative stress in ovaries via the upregulation of PPAR-γ. Curcumin shows promise as a potential drug for the treatment of PCOS.

Synergistic Antioxidant Activity of Lycium barbarum Polysaccharide and Chlorogenic Acid and Its Effect on Inflammatory Response of NR8383 Cells.

It is inevitable for polyphenols and polysaccharides to interact during food preparation. Modifications in microstructure can lead to changes in the physical and chemical properties of food systems, which in turn may influence the nutritional characteristics and functional activities of the food. Recent studies have shown that, in addition to traditional Chinese medicine compounds, certain natural polysaccharides and polyphenols exhibit significant anti-inflammatory and antioxidant properties. These compounds are also associated with beneficial therapeutic effects for the prevention and treatment of acute lung injury. The objective of this study was to examine the synergistic antioxidant effects of chlorogenic acid (CA) and Lycium barbarum polysaccharide (LBP) in various ratios, along with their combined antioxidant and anti-inflammatory effects on LPS-induced inflammation in rat alveolar macrophages. Using the Combination Index (CI), which quantifies the synergistic or antagonistic effect of two substances, all four combinations showed synergistic antioxidant properties over a range of concentrations by in vitro antioxidant property experiments. However, based on comparing them, the four group ratios exhibited the highest antioxidant activity of the infusion at CA:LBP = 1:7, indicating synergistic interactions (CI < 1). In addition, the antioxidant and anti-inflammatory effects of the CA-LBP complex were observed to alleviate cellular inflammatory injury by reducing LPS-induced nitric oxide and reactive oxygen species production and inhibiting the release of inflammatory factors such as TNF-α and IL-6.

Enhanced syngas production via plastic rubber chemical looping gasification: Role of iron–nickel oxide oxygen carriers

To meet the growing demand for efficient waste management solutions, a novel method called Plastic Rubber Chemical Loop Gasification (PRCLG) offers an innovative and effective approach to the thermal treatment of rubber and plastic waste, producing high-purity fuel and hydrogen-rich syngas. In this study, iron-nickel oxide was synthesized and used as an oxygen carrier to facilitate the PRCLG process. The impact of these oxygen carriers on syngas production was thoroughly investigated, and the evolution of the oxygen carrier's activity was analyzed through changes in the microenvironment during the gasification process. Experimental results showed that under pyrolysis conditions at 750 °C, the syngas yield was 1142 mL/g. After introducing a controlled atmosphere with 1.5 mL/h of water vapor, the syngas yield increased to 2150 mL/g. Further enhancement of the syngas yield using a catalyst resulted in a yield of 3562 mL/g, with a carbon conversion rate of 94%. The study confirmed that optimal syngas yields were achieved at 750 °C, highlighting the importance of precise temperature control. Over ten cycles spanning 600 min, the iron-nickel oxide oxygen carrier exhibited stable performance, demonstrating its durability and effectiveness. This innovative PRCLG method not only provides a solution for the disposal of rubber and plastic waste but also contributes to the production of valuable energy resources, aligning with sustainable development goals and advancing waste-to-energy technologies.

Modulation of oxygen vacancies in NiFe layered double hydroxides through dual-doping with Mo/Cr cations for efficient seawater hydrogen production

Seawater splitting to produce hydrogen holds promise for renewable energy but faces challenges from chloride ions, causing electrode corrosion and competition between chlorine oxidation reaction (ClOR) and oxygen evolution reaction (OER). Therefore, it is crucial to develop highly efficient and stable electrocatalysts for seawater splitting. Here, we employ a dual-doping strategy of Mo/Cr cations and a sulfuration approach to fabricate the S-MoCr-NiFe@NF bifunctional catalyst with a 3D nano-flower structure. The S-MoCr-NiFe@NF catalyst exhibits remarkable catalytic performance for the oxygen evolution reaction (OER) in 1.0 M KOH + 0.5 M NaCl and 1.0 M KOH + Seawater, achieving current densities of 10 mA cm−2 at low overpotentials of 116 and 141 mV, respectively. Furthermore, it was demonstrated that the S-MoCr-NiFe@NF catalyst exhibited remarkable performance in alkaline overall seawater splitting, requiring only 1.48 and 1.57 V to achieve current densities of 10 mA cm−2 in 1.0 M KOH + 0.5 M NaCl and 1.0 M KOH + Seawater, respectively. The in-situ Raman and DFT calculations confirm Ni as the primary active sites, reducing the energy barrier of the rate-determining step and enhancing OER performance. This study will offer a viable approach to developing and creating highly effective bifunctional catalysts for seawater splitting.