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We provide a concurrent measurement of the hydrogen and oxygen nuclear kinetic energies in the water molecule across melting at 270 K in the solid phase and 276 K in the liquid phase. Experimental values are obtained by analyzing the neutron Compton profiles of each atomic species in a deep inelastic neutron scattering experiment. The concurrent measurement of the atom kinetic energy of both hydrogen and oxygen allows the estimate of the total kinetic energy per molecule due to the motion of nuclei, specifically 35.3 ± 0.8 and 34.8 ± 0.8 kJ/mol for the solid and liquid phases, respectively. Such a small difference supports results from ab initio simulations and phenomenological models from the literature on the mechanism of competing quantum effects across the phase change. Despite the experimental uncertainties, the results are consistent with the trend from state-of-the-art computer simulations, whereby the atom and molecule kinetic energies in the liquid phase would be slightly lower than in the solid phase. Moreover, the small change of nuclear kinetic energy across melting can be used to simplify the calculation of neutron-related environmental dose in complex locations, such as high altitude or polar neutron radiation research stations where liquid water and ice are both present: for neutron energies between hundreds of meV and tens of keV, the total scattering cross section per molecule in the two phases can be considered the same, with the macroscopic cross section only depending upon the density changes of water near the melting point. [ABSTRACT FROM AUTHOR]

Photocatalytic technology is considered to be a sustainable strategy to convert H2 O and O2 into H2 O2. However, constructing photocatalytically active and stable organic photocatalyst remain a challenge. In this study, a new class of porous aromatic framework photocatalysts (BF-PAFs) were designed and synthesized, in which 9,9′-bifluorenylidene (99′-BF) and different alkynes are alternately connected. The BF-PAFs were constructed and served as photocatalysts for H2 O2 synthesis. Experimental results show that the introduction of different alkynes can effectively regulate the optical band gap and energy band structure, which may further determine their photocatalytic performance. Upon visible light irradiation, PAF-370 exhibits high efficiency for photosynthesis of H2 O2 with a production rate of 730 μmol g–1 h–1 in the presence of sacrificial reagent from water and oxygen via oxygen reduction reaction (ORR) pathway. Furthermore, up to 61 μmol H2 O2 could be generated from this photocatalytic system after 14 hours. [ABSTRACT FROM AUTHOR]

[Display omitted] Combining interfacial oxygen vacancy engineering with a built-in electric field (BEF) technique is an efficient way to build efficient and practical electrocatalytic water-splitting catalysts. In this study, a Fe 3 O 4 -FeSe 2 heterojunction catalyst with oxygen vacancies supported on reduced graphene oxide (rGO) was designed and successfully fabricated using a simple two-step hydrothermal method. Owing to the different Fermi levels of Fe 3 O 4 and FeSe 2 , a BEF was generated at the interface, which enhanced the separation of negative and positive charges, thus optimizing the adsorption of hydrogen/oxygen intermediates on the heterostructures and improving the activity of the catalyst. Experimental results show that Fe 3 O 4 -FeSe 2 /rGO/NF exhibits excellent hydrogen and oxygen evolution performances, with low overpotentials of 234/300 mV at 100 mA⋅cm−2. A water electrolyzer assembled with Fe 3 O 4 -FeSe 2 /rGO/NF as both the anode and cathode requires only a small potential of 1.78 V to reach a current density of 100 mA⋅cm−1. This study provides an innovative approach for constructing a catalyst with excellent electrocatalytic performance for overall water splitting. [ABSTRACT FROM AUTHOR]

All‐perovskite tandem solar cells (TSCs) are gaining increasing attention due to their potential to surpass the efficiency limit of single‐junction solar cells. However, as the bottom low‐bandgap subcells, tin‐lead (Sn‐Pb) perovskites suffer from severe nonradiative recombination at the interfaces due to their susceptibility to oxidation and poor crystalline morphology. Here a surface modifier 4‐(trifluoromethyl)benzhydrazide (TFH) is reported to construct a reductive chemical environment on the surface of perovskite films and protect them from water and oxygen erosion. TFH anchors onto the Sn‐Pb perovskites in a preferred vertical orientation through dual‐site binding, forming interface dipoles that facilitate charge extraction. The reductive hydrazine groups of TFH can effectively inhibit the oxidation of Sn2+ and I−, thereby reducing the defect density and energy disorder of Sn─Pb perovskites. Consequently, the TFH‐treated devices achieved a champion PCE of 22.88%, maintaining over 93% of the initial efficiency after continuous one‐sun illumination for 500 h. Combined with a 1.79 eV wide‐bandgap subcell, it has demonstrated a PCE of 28.17% in all‐perovskite TSCs. [ABSTRACT FROM AUTHOR]

A highly sensitive fluorescence sensor for monitoring low concentrations of hydrogen peroxide was designed. The sensor employs the commercially available palladium or platinum metal on activated charcoal as catalysts to decompose hydrogen peroxide into water and molecular oxygen. The produced oxygen concentration can be measured in real time using an oxygen-sensitive layer doped with photostable oxygen probes. The sensor exhibits high sensitivity that is able to measure hydrogen peroxide concentration down to 20 ppb and can measure hydrogen peroxide concentration in the range of 0.1–100 ppm and 0.02–100 ppm, respectively. The response is fully reversible and the typical response time is less than one minute, which makes it suitable to continuously measure hydrogen peroxide over a long duration. Due to the excellent batch-to-batch consistency of palladium or platinum metal on activated charcoal, the sensor can be massively produced with good reproducibility and affordable price, which holds great potential for constructing sensors for industrial and practical applications. [ABSTRACT FROM AUTHOR]

Introduction: Pore structure and geometry are crucial in scaffold development for tissue engineering. From this viewpoint, pore geometry characterization methods will aid in understanding the influence of pore structure (pore size and diffusivity) on its properties. These properties determine how oxygen and water enter the scaffold, forming adsorption states. Previous studies showed that the addition of graphene (G) to polycaprolactone (PCL) increased the pore size, and played a significant role in tissue regeneration. Therefore, this study aimed to evaluate pore structure, geometry, and viability that are suitable for osteogenesis. Materials and methods: Morphology, size, and size distribution of PCL and PCL/G scaffolds were measured at concentrations of 1, 2, and 3 wt% G for the pore structure, while the connectivity of the scaffold's pore was analyzed using the geodesic tortuosity. This is essential because these factors promote the viability of osteogenesis-supporting cells. Results and discussion: The results showed that 3 wt% G had a good water diffusivity rate, larger pores, better connectivity, and viability than other concentrations. Conclusion: In conclusion, the presence of G in scaffolds affects the pore geometry and structure. This results in several advantageous effects that support osteogenesis, such as increased water and nutrient uptake, enhanced waste metabolism transport, and increased viability of the cells. [ABSTRACT FROM AUTHOR]

Oxygen reduction reaction (ORR) occurs at the cathode of electrochemical devices like fuel cells and in the Huron-Dow process, reducing oxygen to water or hydrogen peroxide. Over the past years, various electrocatalysts with enhanced activity, selectivity, and durability have been developed for ORR. However, an atomic-level understanding of how materials composition affects electrocatalytic performance has not yet been achieved, which prevents us from designing efficient catalysts based on the requirements of practical applications. This is partially because of the polydispersity of traditional catalysts and their unknown structure dynamics in the electrocatalytic reactions. Here we establish a full-spectrum of atomically precise and robust AuxAg25-x(MHA)18 (x = 0–25, and MHA = 6-mercaptohexanoic acid) nanoclusters (NCs) and systematically investigate their composition-dependent catalytic performance for ORR at the atomic level. The results show that, with the increasing number of Au atoms in AuxAg25-x(MHA)18 NCs, the electron transfer number gradually decreases from 3.9 for Ag25(MHA)18 to 2.1 for Au25(MHA)18, indicating that the dominant oxygen reduction product alters from water to hydrogen peroxide. Density functional theory simulations reveal that the Gibbs free energy of OOH adsorption (ΔGOOH*) on Au25 is closest to the ideal ΔGOOH* of 4.22 eV to produce H2O2, while Ag alloying makes the ΔGOOH* deviate from the optimal value and leads to the production of water. This study suggests that alloy NCs are promising paradigms for unveiling composition-dependent electrocatalytic performance of metal nanoparticles at the atomic level. [ABSTRACT FROM AUTHOR]

Understanding the microenvironment structure‐activity relationship of singlet‐atom catalysts (SACs) is imperative for the development of high‐performance photocatalytic devices. However, the challenge remains to finely regulate the coordination microenvironment of SACs. Herein, single‐atom Nx─Cu─O4‐x (x = 1–4) photocatalysts with different coordination environments are successfully prepared based on pre‐design reticular supramolecular covalent organic frameworks (COFs) for direct photocatalytic 1O2 production from O2. The results show that the high activity of Cu SACs is closely related to the N,O‐coordination microenvironment, which is primarily ascribed to the different electrophilicity of the N, O atom. The electron configuration of N3‐Cu‐O1 endows photocatalyst enhanced charge transfer capability and the nearest D‐band center to the Fermi level. The "end‐on" type adsorption configuration of O2 at the N3─Cu─O1 active site can promote the breaking of Cu─O bonds rather than O─O bonds. As a result, the N3‐Cu‐O1@COF photocatalyst exhibits the most optimal formation and desorption energies for intermediates •OOH, which provides an advantageous reaction pathway with fewer steps and a lower barrier for 1O2 production. This work highlights the structure‐activity relationship of SACs for long‐term applications. [ABSTRACT FROM AUTHOR]

The reactive singlet state of oxygen (O2) can decay to the triplet ground state nonradiatively in the presence of a solvent. There is a controversy about whether tunnelling is involved in this nonadiabatic spin-crossover process. Semiclassical instanton theory provides a reliable and practical computational method for elucidating the reaction mechanism and can account for nuclear quantum effects such as zero-point energy and multidimensional tunnelling. However, the previously developed instanton theory is not directly applicable to this system because of a branch-point singularity which appears in the flux correlation function. Here we derive a new instanton theory for cases dominated by the singularity, leading to a new picture of tunnelling in nonadiabatic processes. Together with multireference electronic-structure theory, this provides a rigorous framework based on first principles that we apply to calculate the decay rate of singlet oxygen in water. The results indicate a new reaction mechanism that is 27 orders of magnitude faster at room temperature than the classical process through the minimum-energy crossing point. We find significant heavy-atom tunnelling contributions as well as a large temperature-dependent H2O/D2O kinetic isotope effect of approximately 20, in excellent agreement with experiment. Singlet oxygen relaxes in water to its triplet ground state. Here, the authors show that heavy-atom tunnelling speeds up this reaction from time scales longer than the age of the universe to microseconds. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) has gained increasing attention in artificial photosynthesis of H2O2, yet its performance is hindered by sluggish oxygen reduction reaction (ORR) kinetics and short excited-state electron lifetimes. Here we show a B-doped g-C3N4 (BCN) tailored with coordinatively unsaturated FeOOH and CoOx clusters for H2O2 photosynthesis from water and oxygen without sacrificial agents. The optimal material delivers a 30-fold activity enhancement compared with g-C3N4 under visible light, with a solar-to-chemical conversion efficiency of 0.75%, ranking among the forefront of reported g-C3N4-based photocatalysts. Additionally, an electron transfer efficiency reaches 34.1% for the oxygen reduction reaction as revealed by in situ microsecond transient absorption spectroscopy. Experimental and theoretical results reveal that CoOx initiates hole–water oxidation and prolongs the electron lifetime, whereas FeOOH accepts electrons and promotes oxygen activation. Intriguingly, the key to the direct one-step two-electron reaction pathway for H2O2 production lies in coordinatively unsaturated FeOOH to adjust the Pauling-type adsorption configuration of O2 to stabilize peroxide species and restrain the formation of superoxide radicals. The authors develop a strategy to regulate oxygen reduction reaction kinetics and electron lifetimes with coordinatively unsaturated FeOOH and CoOx clusters to access a direct two-electron pathway for H2O2 photosynthesis on boron-doped g-C3N4. [ABSTRACT FROM AUTHOR]

Allylic amines are prevalent and vital structural components present in many bioactive compounds and natural products. Additionally, they serve as valuable intermediates and building blocks, with wide‐ranging applications in organic synthesis. However, direct α‐C(sp3)−H alkenylation of feedstock amines, particularly for the preparation of α‐alkenylated cyclic amines, has posed a longstanding challenge. Herein, we present a general, mild, operationally simple, and transition‐metal‐free α‐alkenylation of various readily available amines with alkenylborate esters in excellent E/Z ‐ and diastereoselectivities. This method features good compatibility with water and oxygen, broad substrate scope, and excellent functional group tolerance, thereby enabling the late‐stage modification of various complex molecules. Mechanistic studies suggest that the formation of a photoactive electron donor‐acceptor complex between 2‐iodobenzamide and the tetraalkoxyborate anion, which subsequently undergoes photoinduced single electron transfer and intramolecular 1,5‐hydrogen atom transfer to generate the crucial α‐amino radicals, is the key to success of this chemistry. [ABSTRACT FROM AUTHOR]

IrO2 is the benchmark catalyst for acidic oxygen evolution reaction (OER), however, the high cost and low earth abundance hinder its large‐scale application. Herein, surface‐segregated IrCo nanoparticles on CoO nanosheets with a strong electronic interaction are synthesized through the ion exchange‐pyrolysis method. The resulting IrCo−CoO heterostructures, containing an ultra‐low Ir content of 4.73 wt %, demonstrate exceptional performance in the acidic OER. The catalyst exhibits a low overpotential of 270 mV at a current density of 10 mA cm−2 and remarkable stability, with noticeable activity decay observed only after 140 hours of continuous operation. These results surpass most reported Ir‐based electrocatalysts. Specifically, the mass activity at the overpotential of 300 mV for the IrCo−CoO catalyst reaches 124.52 mA mgIr−1, which is 20 times higher than that of commercial IrO2. Furthermore, we constructed a home‐made overall water splitting cell utilizing IrCo−CoO heterostructures as both anode and cathode electrodes, achieving a current density of 10 mA cm‐−2 at a voltage of 1.51 V. Our findings present a promising strategy for designing high‐efficient catalysts with significantly reduced noble metals loading. [ABSTRACT FROM AUTHOR]

Highlights Polypropylene composites with different contents of zinc‐ammonium salts (3, 5 and 7 wt%) and nanocellulose (1 wt%) after enzymatic bioconversion were characterized by structural, dispersion‐morphological, thermal, antimicrobial and mechanical analysis. It was shown that the use of a newly synthesized salt significantly affected the formation of the supermolecular structure of the polymer matrix and increased the nucleation activity, thermostability and flexibility of the composite materials. Moreover, the addition of the inorganic filler allowed to obtain composites with very good antimicrobial properties against Staphylococcus aureus, Escherichia coli and Candida albicans. An interesting relationship between the degree of filler dispersion in the polymer matrix and the formation of polymorphic varieties was elucidated in the study, which contributes to the improvement of final performance characteristics of composite materials. It is noteworthy that a hybrid filler in the form of nanometric cellulose and a biocidal additive containing zinc‐ammonium complex salt was used for the first time. Research has shown that such polymer composites can find application during the manufacture of smart packaging materials with enhanced barrier properties against oxygen and water vapor as well as improved biocidal characteristics, which will notably extend food storage time. At the same time, the presented process of obtaining the innovative composite materials is an excellent example of sustainable technologies for the design of antimicrobial treatments, while guaranteeing the possibility of further processing of these composite materials through material recycling. Zinc‐ammonium complex with antimicrobial properties was obtained The strength properties and thermal stability of the composites were improved Degree of filler dispersion in polymer affects formation of polymorphic varieties The composites can be applied in the production of smart packaging materials [ABSTRACT FROM AUTHOR]

Developing cost-efficient catalysts with high efficiency for water splitting has been considered as large challenge. Herein, the bulk high entropy alloys (HEAs) are fabricated through the vacuum induction melting, which could be beneficial to solving the above issues. At the same time, it also enhances the electrocatalysts activity and stability. The alloy composition is discovered to be crucial in the both hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) activity enhancements with the CoCrFeNiAlMo bulk HEA catalyst combination providing the exceptional catalytic activities. Forming the CoCrFeNiAlMo bulk HEA catalyst also significantly promotes the electrocatalytic cycling stabilities. Hence, the CoCrFeNiAlMo bulk HEA catalyst displays a small overpotential (261 mV @ 50 mA cm−2) and a corresponding Tafel slope (48.66 mV dec−1) for the OER in a 1.0 M KOH electrolyte. For HER, CoCrFeNiAlMo bulk HEA catalyst also possess a relatively small overpotential. Furthermore, it exhibits a relatively small cell voltage of 1.83 V at 50 mA cm−2 and superior durable for 14 h. This study presents a universal pathway for preparing sustainable high efficiency electrocatalysts, it demonstrates that the bulk HEAs have the potential to be effective catalysts in alkaline environments. [Display omitted] • Cost-effective bulk HEAs electrocatalysts are fabricated. • CoCrFeNiAlMo catalyst shows a low overpotential for OER. • Multicomponent property of the HEAs promotes catalytic activities. [ABSTRACT FROM AUTHOR]

Highlights This work investigates the construction of biodegradable packaging film based on polylactic acid (PLA) reinforced with a novel antibacterial hybrid nanofiller to improve barrier and mechanical properties. The study focuses on incorporating silver‐ingrained silica particles (Ag–In–Si) into PLA matrix to prepare the packaging film (Ag–In–SiPLA) that has superior antibacterial, and barrier property with negligible oxygen and water vapour penetration. The Ag was synthesized using natural neem leaf extract as a reducing agent. To ingrain silver over rice husk silica (Si) an in situ technique was adopted. Hence called Ag‐In‐Si bio‐filler. The Ag–In–SiPLA films were fabricated using melt blending and sheet extrusion methods by means of a micro‐compounder. The addition of rice husk silica served the purpose of cost‐effectiveness of the packaging film along with the enhancement of the oxygen and water barrier properties of the films. The optimized sample (PLA loaded with 3% Ag–In–Si), exhibited optimum transparency, moisture resistance, and barrier properties compared with control PLA film. The experiments on Muntingia calabura (Jamaica cherry) preservation have verified the remarkable effectiveness of Ag–In–SiPLA films in preserving their quality for an extended period. These biodegradable packaging films, composed of food‐grade materials and sustainable ingredients, have the potential to provide a compostable and environmentally friendly solution for various packaging applications. This research shed light on the antibacterial Ag–In–SiPLA film as a long‐term, high‐performance fruit packaging solution. Novel antibacterial PLA composite with enhanced barrier and mechanical properties. Silver‐ingrained silica particles improve antibacterial and barrier properties. Green synthesis of silver using neem leaf extract Melt blending and sheet extrusion used to create cost‐effective packaging films. Ag–In–SiPLA films extend Muntingia calabura preservation, proving effective. [ABSTRACT FROM AUTHOR]

Here we show a novel approach to characterize the gas transfer behavior of silicon-oxide (SiO x) coatings and explain the underlying dynamics. For this, we investigate the coating on a nm-scale both by measurement and simulation. Positron annihilation spectroscopy (PAS) and quantum mechanical electronic structure-based molecular dynamics simulations are combined to characterize the porous landscape of SiO x coatings. This approach analyses the influence of micropores smaller than 2 nm in diameter on gas permeation which are difficult to study with conventional methods. We lay out the main pore diameter ranges and their associated porosity estimates. An influence of layer growth on pore size and porosity was found, with an increased energy input during layer deposition leading to smaller pore sizes and a reduced porosity. The molecular dynamics simulations quantify the self-diffusion of oxygen and water vapor through those PAS deducted micropore ranges for hydrophilic and hydrophobic systems. The theoretical pore size ranges are fitting to our PAS results and complete them by giving diffusion coefficients. This approach enables detailed analysis of pore morphology on mass transport through thin film coatings and characterization of their barrier or membrane performance. This is a crucial prerequisite for the development of an exhaustive model of pore dominated mass transports in PECVD coatings. [ABSTRACT FROM AUTHOR]

Oxidative cleavage of aromatic C(sp2)−O bond is important to the conversion of biomass and plastic wastes into value‐added chemicals. Here we put forward the oxidative cleavage of para‐C−O bonds in phenolic compounds in use of oxoammonium salts as oxidant and water as the oxygen source. The mechanism is that oxoammonium cation activates water to form hydroxy‐oxoammonium adduct and thus realizes the ipso‐substitution of 4‐alkoxyphenol, which is proved by substituent effect, isotope labelling experiments, and kinetic analysis. Furthermore, this protocol is successfully applied into the depolymerization of both lignin model compounds with α‐O‐5 and 4‐O‐5 linkages and polyphenylene oxide (PPO). [ABSTRACT FROM AUTHOR]

In addressing the challenge of hypoxia within the tumor microenvironment (TME), a significant obstacle to effective cancer therapy, this research introduces a pioneering nanozyme engineered to utilize water and oxygen as reactants. Utilizing ultrasonic piezoelectricity, this nanozyme converts these substrates into oxygen (O2) and reactive oxygen species, thereby amplifying oxidative stress without relying on endogenous H2O2. This approach involves the strategic engineering of porous ZnSnOv:Mn nanosheets (named MZSO NSs), which are distinguished by oxygen‐rich vacancies and enhanced piezoelectric properties. This breakthrough represents the initial attempt to merge catalytic activities akin to catalase (CAT) with the electrocatalytic oxygen evolution reaction (OER), confirmed through both enzymatic reactions and electrochemical voltammetric analysis. The predominant mechanism of ultrasound‐augmented oxygen generation in MZSO is identified as piezoelectric hole‐induced OER. Supporting theoretical analyses clarify the synergistic impact of oxygen vacancies and Mn doping on the dynamics of carriers and the OER process, leading to a notable increase in catalytic efficiency. These findings highlight the potential of piezoelectric‐enhanced OER electrocatalysts to alleviate hypoxia in the TME, providing novel insights into the development of piezoelectric acoustic sensitizers for the treatment of cancer. [ABSTRACT FROM AUTHOR]

For the sluggish reaction kinetics due to a four‐electron transfer process, water oxidation is always a major obstacle to solar splitting of water to hydrogen. It remains a tough challenge to develop efficient nonnoble‐metal photocatalysts for water oxidation. Herein, we decorate the host photocatalyst of Bi11VO19 nanotubes with the coatalyst of subnanometer MoOx clusters (denoted as Bi11VO19/MoOx hetero‐nanotubes) via a one‐step cation‐exchange solvothermal reaction using Na2V6O16 nanowires as the hard template. It is observed that the morphology and microstructure of Bi11VO19/MoOx hetero‐nanotubes vary with the dosage of Mo source and polyvinylpyrrolidone, as well as with the solvent composition. The optimized Bi11VO19/MoOx hetero‐nanotubes significantly enhance the photooxidation of water to oxygen with visible light, delivering an oxygen production rate of 790 μmol g−1 h−1, which is 12 times that of bare Bi11VO19 nanotubes. In situ X‐ray photoelectron spectroscopy and (photo)electrochemical characterization suggest that the enhanced photoactivity may be caused by the decorated cocatalyst of MoOx clusters, which extracts electrons from Bi11VO19 nanotubes, leaving an abundance of holes for water photooxidation. This work demonstrates a potential strategy to develop photocatalysts for energy conversion by constructing Bi11VO19‐based nanostructures. [ABSTRACT FROM AUTHOR]

Developing high‐efficiency alkaline water splitting technology holds great promise in potentially revolutionizing the traditional petrochemical industry to a more sustainable hydrogen economy. Importantly, the oxygen evolution reaction (OER) accompanied at the anode is considered as a critical bottleneck in terms of both complicated mechanism and sluggish kinetics, requiring rational design of OER electrocatalysts to elucidate the structure‐performance relationship and reduce the applied overpotential. As a benchmarked non‐precious metal candidate, NiFe‐based electrocatalysts have gained enormous attention due to low‐cost, earth‐abundance, and remarkable intrinsic OER activity, which are expected to be implemented in industrial alkaline water splitting. In this contribution, a comprehensive overview of NiFe‐based OER electrocatalysts is provided, starting with fundamental mechanisms, evaluation metrics, and synthetic protocols. Subsequently, basic principles with corresponding regulatory strategies are summarized following the sequence of substrate‐catalyst‐electrolyte design of efficient and robust NiFe‐based electrocatalysts toward industrial‐scale deployment. Perspectives on remaining challenges and instructive opportunities in this booming field are finally discussed. [ABSTRACT FROM AUTHOR]

New mineralogical–petrographical and isotope-geochemical data, as well as numerical simulation results, suggest that high-magnesian basalts and basaltic andesites of the eastern block of the Talmi volcanic structure formed as a result of crystallization differentiation during the rapid ascent of mantle magmas to a depth of ∼7.5 km, under conditions of relatively low oxygen fugacity and water content. We consider acid volcanics (SiO2 ∼76–78 wt %) of the central block as crustal melts, the mixing of which with mantle melts in shallow peripheral chambers leads to the appearance of andesites with numerous mineralogical and geochemical signs of hybridism. The geodynamic position of Triassic volcanism is governed by a transtensional regime under conditions of regionally manifested submeridional compression. [ABSTRACT FROM AUTHOR]

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Using first-principles density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations, we performed this study on the phase stability, the intrinsic redox stability, and the Li+ conductivity of Li10GexMo1−xP2S12 (x = 0~1) superionic conductors. Molybdenum (Mo) is expected to replace expensive germanium (Ge) to lower tmaterial costs, reduce sensitivity to ambient water and oxygen, and achieve acceptable Li+ conductivity. The ab initio first principle molecular dynamics simulations show that room-temperature Li+ conductivity is 1.12 mS·cm−1 for the Li10Ge0.75Mo0.25P2S12 compound, which is comparable to the theoretical value of 6.81 mS·cm−1 and the experimental measured one of 12 mS·cm−1 of the Li10GeP2S12 (LGPS) structure. For Li10GexMo1−xP2S12 (x = 0, 0.25, 0.5 and 1) compounds, the density of states and the projection fractional wave state density were calculated. It was found that when Ge atoms were partially replaced by Mo atoms, the band gap remained unchanged at 2.5 eV, but deep level defects appeared in Mo-substituted compounds. Fortunately, this deep level defect is difficult to ionize at room temperature, so it has no effect on the electronic conductivity of Mo substitute compounds, making Mo substitution a suitable solution for electrolyte materials. The projection fractional wave state density calculation shows that the covalent bond between Mo and S is stronger than that between Ge and S, which reduces the sensitivity of Mo-substituted compounds to water and oxygen contents in the air. In addition, the partial state density coincidence curve between Li and S elements disappears in the 25% Mo-substituted compound with energies of 4–5 eV, indicating that the Li2S by-product is decreased. [ABSTRACT FROM AUTHOR]

The expansion of urban areas has led to land-use changes that affect aquatic biodiversity and ecosystem processes through several ways, such as increased runoff, water pollution, habitat homogenization, and disturbance of the natural flow. It is well known that urbanization induces profound changes in freshwater macroinvertebrate communities, but relatively few studies have approached this topic using trait-based methods. This severely limits our ability to monitor and predict potential alterations of ecosystem processes. We here provide empirical evidence about the effects of urbanization-related changes on the trait composition and functional diversity of freshwater macroinvertebrates from Patagonia (Argentina). Macroinvertebrate sampling and environmental characterization were carried out in 13 study sites distributed across three water courses in the Futaleufú river basin. We found changes in environmental conditions over the urban impact gradient, in turn accompanied by variation in functional diversity and trait composition of aquatic macroinvertebrates. Specifically, we detected lower functional diversity in urban and post-urban reaches, mainly attributed to shifts in the distribution of taxa within the functional space, rather to the extirpation of functionally distinct taxa located at the edges of it (i.e., functional evenness and dispersion decreased, but functional richness remained constant). We also found signs of functional homogenization at the most impaired sites, where gatherers and tegument-breathing taxa dominated. These changes were mainly explained by conductivity, biological oxygen demand, and oxygen levels in the water column. [ABSTRACT FROM AUTHOR]

Laccases are multi‐copper oxidases (MCOs) that oxidize a broad range of substrates while reducing molecular oxygen to water. Although much effort has been made to elucidate the catalytic mechanism of laccases, information about reactive catalytic intermediates during catalysis is not yet fully understood. Herein, hydroquinone (HQ) polymerization catalyzed by prokaryotic small laccase (SLAC) was investigated by electron paramagnetic resonance (EPR) spectroscopy to provide more information on the catalytic mechanism. Briefly, free radical intermediates during the catalysis were investigated by real‐time in situ EPR measurement to monitor the formation and transformation of free radicals. A paramagnetic species was identified which was attributed to a copolymer formed by hydroquinone, benzoquinone, and semiquinone radical. In addition, the low‐temperature EPR spectrum of the trinuclear copper center during catalysis not only revealed tentative rotational motion of the histidine imidazole rings coordinating the TNC upon electron uptake but also provided evidence of the formation of oxygen bridge at TNC during the reaction, represented by the observation of a new type 2 copper component featured larger g// values and smaller A// values. Together, EPR spectroscopic insights into the catalytic intermediates during enzymatic hydroquinone polymerization have extended the knowledge of the biophysical characteristics and catalytic mechanism of SLAC. [ABSTRACT FROM AUTHOR]

In contrast to the high efficiency of room temperature phosphorescence in crystal states, the generally utilized nanoparticles of organic materials in bioimaging demonstrated sharply decreased performance by orders of magnitude under physiological conditions, badly limiting the realization of their unique advantages. This case, especially for organic red/near‐infrared (NIR) phosphorescence materials, is not only the challenge present in reality but more importantly, for the theoretical problem of deeply understanding and avoiding the quenching effect by oxygen and water toward excited triplet states. Herein, thanks to the intelligent molecular design by the introduction of abundant hydrophobic chains and highly‐branched structures, bright and persistent red/NIR phosphorescence under physiological conditions has been realized, which demonstrated the shielding effect towards oxygen, and the strengthened intermolecular interactions to suppress the non‐radiative transitions. Accordingly, the record phosphorescence intensity of nanoparticles in bioimage, up to 8.21±0.36×108 p s−1 cm−2 sr−1, was achieved, to realize the clear phosphorescence imaging of liver and tumors in living mice, even lymph nodes in rabbit models with high SBRs. This work afforded an efficient way to achieve the bright red/NIR phosphorescence nanoparticles, guiding their further applications in biology and medicine. [ABSTRACT FROM AUTHOR]

The successful deployment of efficient oxygen evolution reaction (OER) electrocatalysts is highly essential for multiple clean-energy-related conversion technologies. Perovskite oxides, with compositional diversity and elemental complexity, are a classic kind of OER electrocatalysts, whereas their activity remains insufficient under the traditional adsorbate evolution mechanism (AEM) due to limited scaling relations. Herein, taking the Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) perovskite as a model system, we find a less Ru substitution strategy to boost the lattice oxygen reactivity for improved OER. The OER behavior of BSCF is greatly ameliorated as Ru doping reaches an optimal level (BSCFR0.1), delivering a lowered overpotential by 45 mV at 10 mA cm−2. Notably, such doping remarkably triggers the generation of more surface oxygen vacancies, promotes internal charge transfer, and enlarges the surface hydrophilicity, hence facilitating more lattice oxygen to participate in the surface reaction. These results demonstrate the feasibility of Ru incorporation for ameliorating the OER behavior of perovskites, and such strategy can be further leveraged to design other remarkable perovskite-based OER catalytic materials. • The Ru-doped BSCF series is synthesized by a simple solid-state reaction approach. • The OER behavior is greatly ameliorated as Ru doping reaches an optimal level. • Ru doping can trigger more oxygen vacancies, increase Co–O covalency, and enlarge the surface hydrophilicity. • Such doping also facilitates more lattice oxygen to participate in the surface reaction. [ABSTRACT FROM AUTHOR]

Torrefaction is an effective method to improve the quality of biomass feedstocks for a subsequent thermal conversion process. Torrefaction has been widely developed for biomass upgrading in terms of increasing bulk and energy densities, reducing water and oxygen contents, and improving hydrophobic properties, which are favorable for transportation and storage. Moreover, the torrefied biomass can be easily ground to even particle sizes, which favor the downstream thermochemical conversion process such as gasification. This paper reports on the progress in the dry and wet torrefaction of biomass sources. Key findings and challenges of torrefied biomass gasification are highlighted as well. In general, the properties of biomass feedstocks can be improved by the torrefaction process. Torrefaction for biomass gasification can improve the quality of syngas. In particular, gasification of torrefied biomass involves a merit of volatile matter (tar precursor) removal prior to the gasification process. The properties of torrefied biomass are significantly affected by the torrefaction conditions mainly including atmosphere, temperature, and pressure. The presence of an appropriate amount of oxygen gas leads to a superior performance for biomass torrefaction. The oxygen-containing gas and the waste heat from industrial flue gas can be utilized to reduce the operating cost, thus making the biomass torrefaction pretreatment more commercially feasible. [ABSTRACT FROM AUTHOR]

SiC/SiC composites in aerospace applications are exposed to a variety of thermal conditions, in particular, thermal stress due to rapid heating and cooling. Therefore, it is crucial to investigate and evaluate the resistance of SiC/SiC composites to repeated temperature cycling. This paper investigates the evolution of properties and damage mechanisms of 2D and 2.5D SiC/SiC composites after different thermal shock cycles at 1300 °C. It was found that SiC/SiC composites exhibit a temporary weight increase at the beginning of the thermal shock cycle. Subsequently, the weight decreases and stabilizes as the number of thermal shocks increases. After 10–30 thermal shocks at 1300 °C, the density of SiC/SiC composites decreases while the porosity increases. The fracture behavior of SiC/SiC composites remains the same as that of the initial composites, with 2D SiC/SiC composites exhibiting pseudo-tough fracture and 2.5D SiC/SiC composites exhibiting brittle fracture. The residual strength of the SiC/SiC composites decreased slightly while the residual modulus remained stable. This is related to the reaction of the SiC, and BN with water and oxygen at high-temperature. The thermal shock damage of SiC/SiC composites is anisotropic and is influenced by the structure of the fiber preforms. This is due to the difference in thermal expansion coefficients of the components within the composites and the structural properties of the fiber preforms. [ABSTRACT FROM AUTHOR]

Perovskite is an advanced optoelectronic semiconductor material that has garnered significant attention in recent years. However, its drawback lies in its environmental instability, limiting its practical applications. To tackle this issue, this research delved into the idea of creating a space-confined structure and used electrospinning to produce a film of perovskite nanocomposite fibers. By effectively encapsulating perovskite nanocrystals into a polymer matrix, the perovskite could be shielded from water and oxygen in the environment, thereby reducing the likelihood of perovskite decomposition and enhancing the stability of its structure and properties. This study examined the influence of material composition and the spinning process on the nanofiber structure to create good spatial confinement. This strategy resulted in a high photoluminescence quantum yield of over 80% and a long-term environmental stability of as long as 1000 h over 90% of the original PLQY. By harnessing the flexibility of the composite fibers, this study demonstrated the potential applications and performance of this nanocomposite film in flexible quantum fluorescence conversion for LED applications. [ABSTRACT FROM AUTHOR]

The poor stability, high noise, and low detectivity (D*) of perovskite mesh nanowire (PMN) photodetectors (PDs) seriously hinder their practical applications. Here, a phenylethylamine iodine doping strategy (PIDS) is introduced to solve these problems. The PIDS leads to the formation of 2D perovskite PEA2MAx‐1PbxI3x+1 (PEA = phenylethylamine, MA = methylamine) within MAPbI3 PMN, which not only prevents water and oxygen erosion to thwart PMN degradation but also inhibits the transport of dark state carriers to reduce dark current. As a result, the noise, D*, and stability of the PMN PD are simultaneously improved. The device exhibits low noise current (7.61 × 10−15 A Hz−1/2) and high D* of 3.2 × 1014 Jones, the highest D* value for PMN PDs reported to date. Moreover, the unpacked device sustains 100% of its initial performance after 2880 h of storage in the air (45–55% humidity), enabling it as the most stable MAPbI3 perovskite micro/nanostructure PD reported to date. Furthermore, the flexible device with PIDS exhibits comparable performance to that of the rigid device as well as great mechanical stability. Finally, the flexible device with PIDS demonstrates excellent optical imaging capability and a higher precision optical imaging potential than the commercial silicon photodiode S2386. [ABSTRACT FROM AUTHOR]

Polyelectrolyte complexes (PECs) of Xylan (Xyl) and Chitosan (Ch) were investigated as coating materials to enhance paper properties for food packaging applications. These complexes were blended with different contents of micro/nanofibrillated cellulose (M/NFC) (5–20 wt% of total dry coating weight) to explore potential synergistic effects. The rheological strength and gel properties of the resulting Xyl/Ch PEC-M/NFC formulations were assessed. Coated papers underwent comprehensive analyses, including examinations of morphology, oxygen and water vapor barrier properties, mechanical strength, and printing characteristics. The addition of M/NFC resulted in increased shear viscosity and yield stress of the coating formulations. Additionally, it enhanced the surface wettability of the coated papers, leading to higher contact angles when measured with water and castor oil. Xyl/Ch PEC coated paper exhibited a drastic reduction in Gurley air permeability and development of enhanced barrier properties compared to the base paper. On the other hand, the printing properties, including gamut area, gamut volume and optical density of the Xyl/Ch PEC coated papers, were superior to those of papers coated only with starch. These results demonstrate the promising potential of Xyl/Ch PEC-M/NFC coating formulations for enhancing paper properties and their suitability for food packaging applications. [ABSTRACT FROM AUTHOR]

Surface covalent modification of black phosphorus (BP) with organic polymers represents a promising strategy to enhance its stability and tailor its electronic properties. Despite this potential, developing memristive materials through suitable polymer structures, grafting pathways, and polymerization techniques remains challenging. In this study, polyaniline (PANI)‐covalently grafted black phosphorus nanosheets (BPNS) are successfully prepared with redox functionalities via the in situ polymerization of aniline on the surface of 4‐aminobenzene‐modified BPNS. The PANI coating protects the BP from direct exposure to oxygen and water, and it endows the material with analog memristive properties, characterized by a continuously adjustable resistance within a limited voltage scan range. When subjected to a broader voltage scan, the Al/PANI‐g‐BPNS/ITO device demonstrates a typical bistable digital memristive behavior. The integration of both digital and analog memristive functionalities in a single device paves the way for the development of high‐density, multifunctional electronic components. [ABSTRACT FROM AUTHOR]

The activation of lattice oxygen oxidation mechanism (LOM) will endow iridium‐based electrocatalysts with desired acid‐available water oxidation activity, compared to the conventional adsorbate evolution mechanism (AEM). However, the inherent symmetric [IrO6] octahedra of commercial Ir‐based catalysts generally thermodynamically favor the AEM pathway contributing to the moderate water oxidation performance. Here, based on typical layered Ca2IrO4 (CIO) modeled materials, the d‐orbitals electron repulsion strategy is demonstrated, via constructing asymmetrically polarized Ir‒O‒Ru configuration in Ru‐CIO, to effectively activate the lattice oxygen participating in water oxidation process for decent oxygen‐related electrocatalytic activity. Specifically, a great increase of ≈700‐fold and ≈170‐fold in mass activity and turnover frequency, respectively, has been realized for the optimal Ru‐CIO electrocatalyst in an acid medium relative to the commercial IrO2 electrocatalysts, where a small overpotential of only 175 mV is required for achieving 10 mA cmgeo‒2. In situ X‐ray fine structure spectroscopies combined with in situ 18O‐ isotope‐labeled differential electrochemical mass spectrometry analyses reveal that desirable LOM has been boosted by the activated lattice oxygen and the flexible Ir(3+δ)+ active sites of asymmetric [IrO6] octahedra, which results in superior OER kinetics for Ir‐based oxide catalysts. [ABSTRACT FROM AUTHOR]

Gas starvation significantly affects the uniformity of stack. To reduce this phenomenon, a three‐dimensional, nonisothermal, and two‐phase full‐size liquid‐cooled stack model was developed, and the characteristics of the global and local nonuniformities of oxygen and liquid water in the flow field, membrane temperature, and current density were analyzed under sufficient oxygen supply and three different degrees of gas shortage. Advanced uniformity evaluation criteria (AUEC) were proposed to evaluate the overall uniformity of the stack, which can effectively characterize the local high nonuniformity of the cell units and the differences between edge and intermediate cell units. The results showed that with a decrease in cathode stoichiometric ratio, the AUEC of oxygen, liquid water, membrane temperature, and current density all decreased. The increase in the cooling liquid velocity increased the AUEC of the membrane temperature and current density in the stack, and the AUEC increased further when the oxygen supply was sufficient. In addition, the improvement scheme of GDL gradient porosity was proposed, which can effectively improve the uniformity of each parameter in the stack. [ABSTRACT FROM AUTHOR]

The performance of electrocatalysts is critical for renewable energy technologies. While the electrocatalytic activity can be modulated through structural and compositional engineering following the Sabatier principle, the insufficiently explored catalyst-electrolyte interface is promising to promote microkinetic processes such as physisorption and desorption. By combining experimental designs and molecular dynamics simulations with explicit solvent in high accuracy, we demonstrated that dimethylformamide can work as an effective surface molecular pump to facilitate the entrapment of oxygen and outflux of water. Dimethylformamide disrupts the interfacial network of hydrogen bonds, leading to enhanced activity of the oxygen reduction reaction by a factor of 2 to 3. This strategy works generally for platinum-alloy catalysts, and we introduce an optimal model PtCuNi catalyst with an unprecedented specific activity of 21.8 ± 2.1 mA/cm2 at 0.9 V versus the reversible hydrogen electrode, nearly double the previous record, and an ultrahigh mass activity of 10.7 ± 1.1 A/mgPt. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) perovskite solar cells (PSCs) exhibit better stability compared with three‐dimensional PSCs. However, fundamental questions remain over the chemical phase space in the 2D perovskite framework. Here, phase distribution of alternating cations in the interlayer space 2D perovskite (GA(MA)nPbnI3n+1) is regulated by using potassium salt to control the assembly behavior of colloidal particles and manage the growth of quantum well. The strong affinity between the spacer cation and sulfonate can slow down the intercalation of organic spacer cations to provide a time window for the insertion of MA+, which is conducive to forming high n phase to facilitate the charge transportation. During the crystallization process, potassium salt is extruded to the grain boundary and produce a passivation effect. In this case, the ion migration channels and inlet of water and oxygen are cut off, which is beneficial for the stability of PSCs. A power conversion efficiency of 20.90% is obtained in this work, to the best knowledge, which is the highest PCE for all reported GA(MA)3Pb3I10 perovskite and the large‐area device (1.01 cm2) shows a high efficiency of 18.73 %. Besides, the devices deliver good humidity stability. [ABSTRACT FROM AUTHOR]

The development of novel metal–organic frameworks (MOFs) as efficient photocatalysts for hydrogen peroxide production from water and oxygen is particularly interesting, yet remains a challenge. Herein, we have prepared four cyclic trinuclear units (CTUs) based MOFs, exhibiting good light absorption ability and suitable band gaps for photosynthesis of H2O2. However, Cu‐CTU‐based MOFs are not able to photocatalyzed the formation of H2O2, while the alteration of metal nodes from Cu‐CTU to Ag‐CTU dramatically enhances the photocatalytic performance for H2O2 production and the production rates can reach as high as 17476 μmol g−1 h−1 with an apparent quantum yield of 4.72 %, at 420 nm, which is much higher than most reported MOFs. The photocatalytic mechanism is comprehensively studied by combining the isotope labeling experiments and DFT calculation. This study provides new insights into the preparation of MOF photocatalysts with high activity for H2O2 production through molecular engineering. [ABSTRACT FROM AUTHOR]

Gas exchange in the soil is determined by the size and connectivity of air‐filled pores. Root mucilage reduces air‐filled pore connectivity and thus gas diffusivity. It is unclear to what extent mucilage affects soil pore connectivity and tortuosity. The aim of this study was to gain a better understanding of gas diffusion processes in the rhizosphere by explaining the geometric alterations of the soil pore space induced by mucilage. We quantified the effect of a root mucilage analogue collected from chia seeds without intrinsic respiratory activity on oxygen diffusion at different water contents during drying–rewetting cycles in a diffusion chamber experiment. Quantification of oxygen diffusion showed that mucilage decreased the gas diffusion coefficient in dry soil without affecting air‐filled porosity. Without mucilage, a hysteresis in gas diffusion coefficient during a drying–rewetting cycle was observed. The effect depended on particle size and diminished with increasing mucilage content. X‐ray computed tomography imaging indicated a hysteresis in the connectivity of the gas phase during a drying–rewetting cycle for samples without mucilage. This effect was attenuated with increasing mucilage content. Furthermore, electron microscopy showed that mucilage structures formed in drying soil increase with mucilage content, thereby progressively reducing the connectivity of the gas phase. In conclusion, the effect of mucilage on soil gas diffusion highly depends on soil texture and mucilage content. The diminishing hysteresis with the addition of mucilage suggests that plant roots secrete mucilage to balance oxygen availability and water content, even under fluctuating moisture conditions. [ABSTRACT FROM AUTHOR]

Flavodiiron proteins (FLVs) catalyze the reduction of oxygen to water by using electrons from Photosystem I (PSI). In several photosynthetic organisms such as cyanobacteria, green algae, mosses and gymnosperms, FLV-dependent electron flow protects PSI from over-reduction and consequent damage especially under fluctuating light conditions. In this work we investigated biochemical and structural properties of FLVA and FLVB from the model moss Physcomitrium patens. The two proteins, expressed and purified from Escherichia coli, bind both iron and flavin cofactors and show NAD(P)H oxidase activity as well as oxygen reductase capacities. Moreover, the co-expression of both FLVA and FLVB, coupled to a tandem affinity purification procedure with two different affinity tags, enabled the isolation of the stable and catalytically active FLVA/B hetero tetrameric protein complex with cooperative nature. The multimeric organization was shown to be stabilized by inter-subunit disulfide bonds. This investigation provides valuable new information on the biochemical properties of FLVs, with new insights into their in vivo activity. [ABSTRACT FROM AUTHOR]

Amino-cured epoxy resins are widely used in the electrical and electronic industry for their excellent properties. To investigate the mechanism of the effect of O2 and H2O on the pyrolysis behavior of epoxy resin, in this paper, the cross-linked structure of bisphenol A type epoxy resin cured by adducts of diethylenetriamine and butyl glycidyl ether is modeled based on the ReaxFF force field, and the thermal decomposition processes at different temperatures and gas atmospheres were simulated and the pathways of the small molecule products were clarified. The results show that epoxy resin will produce small molecule gas products, such as H2, CO, H2O, OH, CH2O, and free radicals, in the process of pyrolysis; the presence of amino groups also generates nitrogen-containing radicals, such as CN, CH2N, and C2H4N; as the reaction temperature increases, the rate of pyrolysis reaction will be accelerated. The same temperature in oxygen and water atmospheres can accelerate the breakage of epoxy resin main chain by promoting the breakage of carbon and oxygen bonds and, at the same time, promote the generation of small molecule gases, such as H2 and CO. [ABSTRACT FROM AUTHOR]

During the Rhuddanian–Aeronian interglacial period, global geological events such as glacial melting, synsedimentary volcanic activity, biological resurgence, and large-scale marine transgressions caused frequent fluctuations in paleoproductivity, climate changes, and sea level variations. These paleoenvironmental transitions directly influenced the development characteristics of shale lithofacies. This study investigates the Longmaxi Formation shale in the Changning area in the Southern Sichuan basin, focusing on 28 core samples from Well N1. Using scanning electron microscopy, QEMSCAN, TOC, XRD, and major and trace element analyses, we reconstructed the paleoenvironmental transitions of this period and explored their control over shale lithofacies types and mineral compositions. Four shale lithofacies were identified: carbonate rich lithofacies (CRF), biogenic quartz-rich lithofacies (BQRF), detrital clay-rich lithofacies (CRDF), and detrital quartz-rich lithofacies (DQRF). During the Rhuddanian period, rising global temperatures caused glacial melting and rapid marine transgressions. The low oxygen levels in bottom waters, combined with upwelling and abundant volcanic material, led to high paleoproductivity. This period primarily developed BQRF and CRF. Rich nutrients and abundant siliceous organisms, along with anoxic to anaerobic conditions, provided the material basis and preservation conditions for high biogenic quartz and organic matter content. High paleoproductivity and anoxic conditions also facilitated the precipitation of synsedimentary calcite and supplied Mg2+ and SO42− for the formation of iron-poor dolomite via sulfate reduction. From the Late Rhuddanian to the Mid-Aeronian, the Guangxi orogeny caused sea levels to fall, increasing water oxidation and reducing upwelling and volcanic activity, which lowered paleoproductivity. Rapid sedimentation rates, stepwise global temperature increases, and the intermittent intensification of weathering affected terrigenous clastic input, resulting in the alternating deposition of CRF, CRDF, and DQRF. Two favorable shale gas reservoirs were identified from the Rhuddanian–Aeronian period: Type I (BQRF) in the L1–L3 Layers, characterized by high TOC and brittleness, and Type II (DQRF) in the L4 Layer, with significant detrital quartz content. The Type I-favorable reservoir supports ongoing gas production, and the Type II-favorable reservoir offers potential as a future exploration target. [ABSTRACT FROM AUTHOR]

Sn-based halide perovskites are expected to be the best replacement for toxic lead-based counterparts, owing to their similar ionic radii and the optimal band gap for use in solar cells, as well as their versatile use in light-emitting diodes and photodetection applications. Concerns, however, exist about their stability under ambient conditions, an issue that is exacerbated in polycrystalline films because grain boundaries present large concentrations of defects and act as entrance points for oxygen and water, causing Sn oxidation. A current thriving research area in perovskite materials is the fabrication of perovskite single crystals, promising improved optoelectronic properties due to excellent uniformity, reduced defects, and the absence of grain boundaries. This review summarizes the most recent advances in the fabrication of single crystal Sn-based halide perovskites, with emphasis on synthesis methods, compositional engineering, and formation mechanisms, followed by a discussion of various challenges and appropriate strategies for improving their performance in optoelectronic applications. [ABSTRACT FROM AUTHOR]

The production of hydrogen through urea electrolysis exhibits many advantages such as low consumption, cost-effectiveness, high efficiency, and environmental friendliness. Here, a layered triple hydroxide (BiCoAl-LTH) was grown in situ on nickel foam (NF) to prepare a self-supported electrode. The BiCoAl-LTH/NF electrode exhibits a unique two-dimensional array structure. Since Al is easily etched in a strong alkaline solution, a large number of oxygen vacancies are generated, which is conducive to improving the conductivity of BiCoAl-LTH/NF catalyst and thereby enhancing its urea oxygen reaction (UOR) activity. The BiCoAl-LTH/NF can achieve a current density of 100 mA/cm2 at an overpotential of 198 mV in UOR process. The BiCoAl-LTH/NF was used as both the anode and cathode to construct a urea electrolysis system. A current density of 100 mA/cm2 can be achieved with only a cell voltage of 1.65 V. Compared to conventional water electrolysis with the oxygen evolution reaction at the anode, the BiCoAl-LTH/NF catalyst can save 40% of energy in urea electrolysis for hydrogen production. [ABSTRACT FROM AUTHOR]

Summary: The development of edible films, which serve as a safe alternative to synthetic polymers by utilising by‐products from the agricultural industry, has become a focus of research as they contribute to the sustainable use of resources. In the present study, quince seed gel (QSG) and whey protein concentrate (WPC) (1:1 w/w) were used as base components to develop edible films using glycerol as a plasticiser. The proteins were sonicated to denature and then the proteins were modified by cross‐linking with the enzyme transglutaminase (TGase). The thickness, moisture content, solubility, permeability and digestibility of each edible films were investigated. In addition to the morphological, mechanical, optical, thermal and structural properties, the edible films were further characterised. The thickness, moisture, water vapour and oxygen permeability and the water solubility of the films were positively influenced by the cross‐linking and the digestibility of proteins decreased with the cross‐linking. A remarkable change in the secondary structures was observed in the FTIR spectra of the films. The stronger networks and their smooth surface of crosslinked films were confirmed by AFM images. The results of this research shows that QSG/WPC films cross‐linked with TGase have potential for use in food packaging systems due to their advantages and may be an attractive alternative to synthetic materials in further studies. [ABSTRACT FROM AUTHOR]

The production of oxygen through phytoplankton photosynthesis is a crucial phenomenon in the dynamics of marine ecosystems. A generic oxygen-phytoplankton interaction model is considered to comprehend its underlying mechanism. This paper investigates the discrete-time dynamics of oxygen and phytoplankton in aquatic ecosystems, incorporating factors that cause phytoplankton mortality due to external influences. We explore the conditions for the local stability of steady states concerning the oxygen content in dissolved water and phytoplankton density. The analysis reveals that the model undergoes a co-dimension one bifurcation, encompassing flip and Neimark–Sacker bifurcations, utilizing the center manifold theorem and bifurcation theory. To manage the chaos resulting from the Neimark–Sacker bifurcation, we apply the OGY feedback control method and a hybrid control methodology. Finally, we present numerical simulations to validate the theoretical discussion. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) as semiconductor‐like materials, are considered to be promising photocatalysts for heterogeneous phtotocatalytic oxidation of styrene. Herein, copper‐based MOFs and titanium dioxide composite bifunctional photocatalyst (Cu–benzene‐1,3,5‐tricarboxylate‐titanium dioxide, Cu‐BTC‐TiO2) wereas synthesized, and the selective oxidation of styrene was achieved under mild conditions of oxygen and water. Cu‐BTC‐TiO2 nanoparticles (NPs) exhibited more than three times higher styrene conversion than Cu‐BTC and TiO2 individually under same condition, and the desired product benzaldehyde can be obtained with up to 82% yield. The improved performance may be attributed to the acid site of Cu‐BTC, which is conducive to the adsorption and activation of styrene. In addition, the formation of heterojunction between Cu‐BTC and TiO2 can regulate the band gap of photocatalyst, which is favorable for light absorption, and facilitate the separation, transportation and utilization of photogenerated electron holes. The present protocol features good functional group tolerance, mild reaction conditions, and the reusability of catalyst. [ABSTRACT FROM AUTHOR]

Halogen bonds find application in supramolecular chemistry, DNA Holliday junction, drug design, organic catalysis and various other fields. Coumarin derivatives are high in demand due to their application in photochemotherapy, drugs and other cancer treatments. Halogenated coumarins are widely known for their biological activities. There exists a competition between the halogen bond and hydrogen bond in singly hydrated halogenated coumarins. The competition between hydrogen and halogen bonding interactions in 3-halogenated 4-hydroxyl coumarin [coumarin derivative; halogen, X = F (A), Cl (B), Br (C), I (D)] with water molecule in the corresponding binding regions C3–X and C2=O4 is studied. This study was conducted using PBE0 D3BJ with augmented correlation consistent basis set in order to include the diffuse functions. Improved findings for non-bonded distances and much more distinct intramolecular effects were obtained using BJ-damping. In the singly-hydrated systems, the water molecule forms a hydrogen bond with C2=O4 in all the halogenated molecules, whereas halogen bonding between the water oxygen and C2–X exists only in the case of X = Br (C) and I (D). The absence of a halogen-bonded structure in singly-hydrated chlorine and fluorine substituted coumarin derivative is therefore attributed to the competing hydrogen-bonding interaction with C2=O4. RDG scatter plot as well QTAIM analysis implied that halogen bond exists between water molecule and the coumarin derivative. Further, the most modern local energy decomposition (LED) analysis of intermolecular interaction was also studied using DLPNO-CCSD(T). Finally, ab initio molecular dynamics was also performed. [ABSTRACT FROM AUTHOR]

This study provides an insight into a comprehensive study on two soft clay deposits namely Kuttanad and Cochin marine clays from the south western state of Kerala, India. These clays are deltaic formations that possess low shear strength and high compressibility characteristics. Many cases of large post construction settlements and failures have been reported from these regions. Additionally, these clays are popular for undergoing irreversible changes in properties on drying and there were many theories associated with this trend for both clays; the significant reasons attributed being the presence of organic matter, the aggregations assisted by the exchangeable di-valent and tri-valent cations and high pore fluid salinity. The question of which was the predominant reason was a point of discussion in the past. In this paper, the similarities and dissimilarities of the two clays have been brought out. The irreversible nature of properties on drying was investigated for both clays using physicochemical techniques and FTIR Spectroscopy. Subsequently, a high energy dispersion tool, generally used for emulsification, was employed in an attempt to reverse the properties of the dried clays. While there was significant reversal of the properties in Cochin marine clay (CMC), it was only about 75 to 80% in Kuttanad clay. A detailed FTIR analysis indicated the presence of strong hydrogen bonds between the interlayer water and basal oxygens of kaolin-like layers in Kuttanad clay that is characteristic of the halloysite mineral. The presence of halloysite, higher salinity and organic matter of Kuttanad clay compared to CMC could be the major factor leading to the incomplete reversal of the properties for Kuttanad clay on drying. [ABSTRACT FROM AUTHOR]