Oxide Oxygen Research Articles

Advances in Oxygen Evolution Reaction Electrocatalysts via Direct Oxygen-Oxygen Radical Coupling Pathway.

Oxygen evolution reaction (OER) is a cornerstone of various electrochemical energy conversion and storage systems, including water splitting, CO2/N2 reduction, reversible fuel cells, and rechargeable metal-air batteries. OER typically proceeds through three primary mechanisms: adsorbate evolution mechanism (AEM), lattice oxygen oxidation mechanism (LOM), and oxide path mechanism (OPM). Unlike AEM and LOM, the OPM proceeds via direct oxygen-oxygen radical coupling that can bypass linear scaling relationships of reaction intermediates in AEM and avoid catalyst structural collapse in LOM, thereby enabling enhanced catalytic activity and stability. Despite its unique advantage, electrocatalysts that can drive OER via OPM remain nascent and are increasingly recognized as critical. This review discusses recent advances in OPM-based OER electrocatalysts. It starts by analyzing three reaction mechanisms that guide the design of electrocatalysts. Then, several types of novel materials, including atomic ensembles, metal oxides, perovskite oxides, and molecular complexes, are highlighted. Afterward, operando characterization techniques used to monitor the dynamic evolution of active sites and reaction intermediates are examined. The review concludes by discussing several research directions to advance OPM-based OER electrocatalysts toward practical applications.

Acidic oxygen evolution reaction via lattice oxygen oxidation mechanism: progress and challenges

The lattice oxygen mechanism (LOM) plays a critical role in the acidic oxygen evolution reaction (OER) as it provides a more efficient catalytic pathway compared to the conventional adsorption evolution mechanism (AEM). LOM effectively lowers the energy threshold of the reaction and accelerates the reaction rate by exciting the oxygen atoms in the catalyst lattice to directly participate in the OER process. In recent years, with the increase of in-depth understanding of LOM, researchers have developed a variety of iridium (Ir) and ruthenium (Ru)-based catalysts, as well as non-precious metal oxide catalysts, and optimized their performance in acidic OER through different strategies. However, LOM still faces many challenges in practical applications, including the long-term stability of the catalysts, the precise modulation of the active sites, and the application efficiency in real electrolysis systems. Here, we review the application of LOM in acidic OER, analyze its difference with the traditional AEM mechanism and the new oxide pathway mechanism (OPM) mechanism, discuss the experimental and theoretical validation methods of the LOM pathway, and prospect the future development of LOM in electrocatalyst design and energy conversion, aiming to provide fresh perspectives and strategies for solving the current challenges.

Sodium, the Vascular Endothelium, and Hypertension: A Narrative Review of Literature.

The vascular endothelium and its endothelial glycocalyx contribute to the protection of the endothelial cells from exposure to high levels of sodium and help these structures maintain normal function by regulating vascular permeability due to its buffering effect. The endothelial glycocalyx has negative surface charges that bind sodium and limit sodium entry into cells and the interstitial space. High sodium levels can disrupt this barrier and allow the movement of sodium into cells and extravascular fluid. This can generate reactive oxygen species that inhibit nitric oxide production. This leads to vasospasm and increases intravascular pressures. Overtime vascular remodeling occurs, and this changes the anatomy of blood vessels, their intrinsic stiffness, and their response to vasodilators and results in hypertension. Patients with increased salt sensitivity are potentially at more risk for this sequence of events. Studies on the degradation of the glycocalyx provide insight into the pathogenesis of clinical disorders with vascular involvement, but there is limited information available in the context of higher concentrations of sodium. Data on higher intake of sodium and the imbalance between nitric oxide and reactive oxygen species have been obtained in experimental studies and provide insights into possible outcomes in humans. The current western diet with sodium intake above recommended levels has led to the assessment of sodium sensitivity, which has been used in different populations and could become a practical tool to evaluate patients. This would potentially allow more focused recommendations regarding salt intake. This review will consider the structure of the vascular endothelium, its components, the effect of sodium on it, and the use of the salt blood test mini.

Performance of Granulated Ti-Dopped Manganese Oxide Oxygen Carriers in Chemical Looping Processes

The cornerstone in the development of different applications of the Chemical Looping (CL) technology is the oxygen carrier material that transfers the oxygen. We evaluate the performance of manganese oxide doped with TiO2 to reinforce the release of molecular oxygen and regeneration at high temperatures (850–950 °C). Different manganese-titanium mixed oxides with mass fractions of titanium oxide from 0 to 50 wt.% were considered and prepared by granulation. The sample with 20 wt.%. TiO2 (MnTi_20) showed better oxygen release/regeneration capabilities than pure manganese oxide under similar conditions and was selected for further development. To evaluate the performance of MnTi_20, long tests (200 cycles) were carried out in a TGA to evaluate the chemical and mechanical stability of the sample. Additionally, MnTi_20 was tested in a batch fluidized bed reactor to evaluate its oxygen uncoupling capability and its reactivity with the main combustion gases (H2, CO, and CH4) as well as its fluidization properties. MnTi_20 is capable of regenerating Mn3O4 to Mn2O3 at 950 °C and maintains its reactivity with the redox cycles. No fluidization problems were encountered during almost 60 h of continuous fluidization, and a lifetime of 2500 h was estimated for this oxygen carrier.

Rbfox3 Promotes Transformation of MDSC-Like Tumor Cells to Shape Immunosuppressive Microenvironment.

Myeloid-derived suppressor cells (MDSCs) within the tumor microenvironment (TME) contribute to the malignant progression of tumors by exerting immunosuppressive effects. Bacterial lipopolysaccharides (LPS) have been widely demonstrated in various types of solid tumors. LPS can promote the malignant progression of tumors, which mechanism has not yet been fully elucidated. In this study, a type of MDSC-like tumor cells (MLTCs) is found in tumor tissues induced by low-dose and long-term LPS stimulation. MLTCs can simultaneously express tumor cell and MDSCs markers. Similar to MDSCs, MLTCs can produce arginine, nitric oxide, and reactive oxygen species and inhibit the activity of NK and T cells to promote the formation of an immunosuppressive microenvironment. MLTCs can also promote tumor cell proliferation and vasculogenic mimicry formation. CRISPR-Cas9 activity screening studies identified RNA-binding Fox-1 homolog 3 (Rbfox3) as a critical protein for MLTCs formation after LPS treatment. Rbfox3 can transcriptionally regulate the expression of Ass1 in the form of phase-separated particles. Crocin can inhibit the generation of MLTCs by disrupting phase-separated particles of Rbfox3 and enhance the anti-tumor effects of immune checkpoint inhibitors (ICIs).

Thick and dense nitrogen-doped hafnium carbide ultra-high temperature thermal protection coating for outstanding ablation resistance up to 2600 ℃

Transition metal carbon-nitrides, typically represented by HfCN, have become the latest progress among the ultra-high temperature ceramics. In this study, single-phase solid solution HfCN coating was successfully synthesized from spray granulated HfC-HfN composite powder followed by employing the dual solid solution effects of radio frequency inductively coupled plasma spheroidization and supersonic atmospheric plasma spraying processes. The coating was nearly dense (only 2.3% in porosity) with a high thickness of ~ 270 μm. Compared with HfC coating, the HfCN coating exhibited higher hardness and elastic modulus. After plasma ablation at a high heat flux of 8.2MW/m2 for 200s, the HfCN coating exhibited a surface temperature of up to 2600 ℃ and can firmly protect the refractory tungsten substrate from oxidation failure. This outstanding performance illustrates that doping N element in HfC crystal can effectively improve the energy barrier for oxidation reaction and oxygen adsorption compared with typical HfC coating.

Small but mighty: nanoemulsion particle size dictates bone regeneration potential of FTY720.

The burgeoning field of nano-bone regeneration is yet to establish a definitive optimal particle size for nanocarriers. This study investigated the impacts of nanocarrier's particle size on the bone regeneration efficacy of fingolimod (FTY720)-loaded nanoemulsions. Two distinct particle sizes (60 and 190 nm, designated as NF60 and NF190, respectively) were produced using low-energy and high-energy emulsion techniques, maintaining a consistent surfactant, co-surfactant, and oil. In vitro studies using rat mesenchymal stem cells revealed that both NF60 and NF190 exhibited cell viability and reduced lactate dehydrogenase. Interestingly, NF60 demonstrated superior antioxidant properties, significantly reducing nitric oxide and intracellular reactive oxygen species (ROS) levels compared to NF190. Furthermore, NF60 significantly enhanced ALP activity and calcium deposition during osteogenic differentiation, indicating its potential to promote the early stages of bone formation. In vivo studies using a rat calvarial bone defect model demonstrated that both NF60 and NF190 significantly upregulated the expression of key osteogenic genes, including Runx2, Col, ALP, OCN, and BMP2. Notably, NF60 induced significantly higher expression of Runx2 and BMP2. X-ray and histological investigations revealed significantly improved bone regeneration in the NF60 group, highlighting the superior bone healing potential of smaller FTY720 nanoemulsions, without infiltration of inflammatory cells. The smaller particle size demonstrated superior antioxidant properties, enhanced osteogenic differentiation, and improved bone regeneration, suggesting smaller nanoparticles, with their larger surface area, accelerated drug release rate, and lower viscosity, interact more effectively with cells, leading to increased and effective drug delivery and cellular uptake. Findings highlight the importance of nanocarrier size in optimizing drug delivery for bone tissue engineering applications.

Hypoxia Combined With Interleukin-17 Regulates Hypoxia-Inducible Factor-1α/Endothelial Nitric Oxide Synthase Expression in Pulmonary Artery Endothelial Cells.

The pathogenesis of chronic thromboembolic pulmonary hypertension may be multifactorial and requires further studies. We explored alterations in pulmonary artery endothelial cells under the hypoxic and elevated interleukin-17 conditions that are commonly present in patients with chronic thromboembolic pulmonary hypertension. We measured the serum interleukin-17 levels in 10 chronic thromboembolic pulmonary hypertension patients and 10 healthy control persons. The expressions and localisations of hypoxia-inducible factor-1α and endothelial nitric oxide synthase were detected in tissues. The levels of hypoxia-inducible factor-1α, endothelial nitric oxide synthase, nitric oxide, and reactive oxygen species in cultured pulmonary artery endothelial cells were examined under hypoxia and/or interleukin-17 treatment. The serum interleukin-17 level was increased in chronic thromboembolic pulmonary hypertension patients. Hypoxia-inducible factor-1α was increased, and endothelial nitric oxide synthase was decreased in chronic thromboembolic pulmonary hypertension pulmonary vascular tissue. After receiving the hypoxia combined with interleukin-17 treatment, pulmonary artery endothelial cells showed increased levels of hypoxia-inducible factor-1α and phospho-endothelial nitric oxide synthase (Thr495) (p = 0.001 and 0.063, respectively) and a decreased level of endothelial nitric oxide synthase (p < 0.001). In addition, the nitric oxide level was significantly decreased (p = 0.001), whereas the reactive oxygen species level was insignificantly increased in pulmonary artery endothelial cells. Chronic thromboembolic pulmonary hypertension patients might experience increased inflammation and hypoxia due to dysregulation of the hypoxia-inducible factor-1α/endothelial nitric synthase pathway in pulmonary artery endothelial cells under inflammation and hypoxia, contributing to the pathogenesis of chronic thromboembolic pulmonary hypertension.

The effect of humic substances on the functional state of internal organs and antioxidant status in dogs with myxomatous mitral valve disease

Oxidative stress and reactive oxygen species imbalance have a multifactorial harmful effect on the cardiovascular system, which leads to dysregulation of calcium channels, formation of fibrosis, apoptosis, hypertrophy of cardiomyocytes, as well as inflammatory processes. The role of impaired redox reactions in the body of animals suffering from myxomatous mitral valve disease (MMVD) has not been sufficiently studied. That is why the goal of our research was to study the impact of heart disease on the formation of oxidative stress, as well as to analyse the use of a remedy based on humic substances on the formation of antioxidant protection and the functional state of the organs of the abdominal cavity. The results of our study showed that humic substances do not have a negative effect on kidney function and protein metabolism. Serum levels of electrolytes, namely sodium, potassium, and chlorine, did not show any changes in either group during the study period. The functional state of the hepatobiliary system during the use of humic substances also did not change and did not exceed the threshold values. Thus, the level of ALT on the 21st day of the study in the group of standard therapy (ST) and the group of animals that received humic compounds along with standard therapy (STH) increased by 12.8 % and 20.4 %, respectively. The level of AST in the ST group decreased by 7.9 % and in the STH group it increased by 3.8 %. Indicators of antioxidant protection activity significantly changed by the 21st day of the study in the STH group, so the level of SOD decreased by 25 %, and the level of catalase, on the contrary, increased by 28.5 %. In general, the obtained results indicate the absence of toxic effects of humic substances on the functional state of the hepatobiliary system and kidneys, and demonstrate improvement of the antioxidant protection of the body of dogs with MMVD stage C according to the classification of the American College of Veterinary Internal Medicine.

Endothelial Dysfunction and Cardiovascular Disease: Hyperbaric Oxygen Therapy as an Emerging Therapeutic Modality?

Maintaining the physiological function of the vascular endothelium and endothelial glycocalyx is crucial for the prevention of cardiovascular disease, which is one of the leading causes of morbidity and mortality worldwide. Damage to these structures can lead to atherosclerosis, hypertension, and other cardiovascular problems, especially in individuals with risk factors such as diabetes and obesity. Endothelial dysfunction is associated with ischemic disease and has a negative impact on overall cardiovascular health. The aim of this review was to comprehensively summarize the crucial role of the vascular endothelium and glycocalyx in cardiovascular health and associated thrombo-inflammatory conditions. It highlights how endothelial dysfunction, influenced by factors such as diabetes, chronic kidney disease, and obesity, leads to adverse cardiovascular outcomes, including heart failure. Recent evidence suggests that hyperbaric oxygen therapy (HBOT) may offer therapeutic benefits in the treatment of cardiovascular risk factors and disease. This review presents the current evidence on the mechanisms by which HBOT promotes angiogenesis, shows antimicrobial and immunomodulatory effects, enhances antioxidant defenses, and stimulates stem cell activity. The latest findings on important topics will be presented, including the effects of HBOT on endothelial dysfunction, cardiac function, atherosclerosis, plaque stability, and endothelial integrity. In addition, the role of HBOT in alleviating cardiovascular risk factors such as hypertension, aging, obesity, and glucose metabolism regulation is discussed, along with its impact on inflammation in cardiovascular disease and its potential benefit in ischemia-reperfusion injury. While HBOT demonstrates significant therapeutic potential, the review also addresses potential risks associated with excessive oxidative stress and oxygen toxicity. By combining information on the molecular mechanisms of HBOT and its effects on the maintenance of vascular homeostasis, this review provides valuable insights into the development of innovative therapeutic strategies aimed at protecting and restoring endothelial function to prevent and treat cardiovascular diseases.

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.

Potent phytoceuticals cocktail exhibits anti-inflammatory and antioxidant activity on LPS-triggered RAW264.7 macrophages in vitro.

Chronic inflammatory conditions, which include respiratory diseases and other ailments, are characterized by persistent inflammation and oxidative stress, and represent a significant health burden, often inadequately managed by current therapies which include conventional inhaled bronchodilators and oral or inhaled corticosteroids in the case of respiratory disorders. The present study explores the potential of Vedicinals®9 Advanced, a polyherbal formulation, to mitigate LPS-induced inflammation and oxidative stress in RAW264.7 mouse macrophages. The cells were pre-treated with Vedicinals®9 Advanced, followed by exposure to LPS to induce an inflammatory response. Key experimental outcomes were assessed, including nitric oxide (NO) and reactive oxygen species (ROS) production, as well as the expression of inflammatory and oxidative stress-related genes and proteins. Vedicinals®9 Advanced significantly reduced LPS-induced NO and ROS production, indicating strong anti-inflammatory and antioxidant properties. Additionally, the formulation downregulated the LPS-upregulated mRNA expression of pro-inflammatory cytokines, such as TNF-α and CXCL1, and oxidative stress markers, including GSTP1 and NQO1. Furthermore, Vedicinals®9 Advanced downregulated the LPS-induced protein expression of the chemokines CCL2 and CCL6, the LPS co-receptor, CD14, and the pro-inflammatory cytokines G-CSF and IL-1β. These findings highlight the potential of Vedicinals®9 Advanced as a therapeutic option for managing CRDs and other inflammatory conditions. The formulation's ability to simultaneously target inflammation and oxidative stress suggests it may offer advantages over existing treatments, with potential for broader application in inflammatory diseases.

Reactive Oxygen and Nitrogen Species - "Nanosweeper" for Rheumatoid Arthritis Theranostics by Macrophage Reprogramming.

Excessive reactive oxygen and nitrogen species (RONS) accumulation in joints are significant variables that affect the course of rheumatoid arthritis (RA). Scavenging of RONS to remodel macrophage homeostasis is a potentially powerful treatment for RA. Here, a visualized "nanosweeper" by functionalizing ultrasmall Gd/Fe3O4 nanoparticles with thiol-polyethylene glycol-phosphoric acid and 2-(3-(2-aminophenyl)ureido) ethyl methacrylate hydrochloride (APUEMA), namely GIA NPs, can simultaneously scavenge both nitric oxide (NO) and reactive oxygen species (ROS), as well as enhance magnetic resonance imaging (MRI) for the diagnosis and therapy of RA. GIA NPs could not only eliminate NO by reactions between the o-phenylenediamine moieties of APUEMA and NO molecules but also remove ROS by the superoxide peroxidase activities of the Fe3O4 nanoparticles and thiol. In vitro and in vivo experiments revealed that the simultaneous scavenging of NO and ROS strategy inhibited the overactivation of the cyclic guanosine monophosphate/protein kinase G (cGMP/PKG) signaling pathway to reprogram the polarization states of macrophages and interfered with metabolism to alleviate RA. In addition, GIA NPs, as dual-modal nanoprobes for MRI, exhibited the capacity for the early diagnosis of RA lesions and monitoring during the RA treatment process. The visualized "nanosweeper" strategy provides a promising integrated platform for the diagnosis and treatment of RA.

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.

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.

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.

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.