搜索结果：Inorganic Chemistry

Understanding how different C1 carbon sources participate in photocatalytic reduction is essential for clarifying carbon conversion pathways beyond conventional CO2-centric descriptions. Herein, polar chalcohalide photocatalysts SbSI and SbSeI are systematically investigated for the light-driven reduction of representative molecular and inorganic C1 carbon sources, including HCHO, HCOOH, CH3OH, NaHCO3, and CaCO3. Time-resolved product evolution, quantitative yields (μmol·g-1·h-1), and selectivity were determined using GC-TCD/FID and GC-MS. Across all systems, hydrogen evolution dominates the reaction network, methane is the primary carbon-containing product, and C2+ hydrocarbons appear as minor products, while CO and oxygen-containing organics are not detected. Molecular C1 substrates establish hydrogen-rich reaction environments that favor deep reduction and saturated hydrocarbon formation, whereas bicarbonate and carbonate sources exhibit reduced activity but enhanced formation of unsaturated C2+ hydrocarbons. These results establish a unified, experimentally driven framework for carbon-source-dependent photocatalytic reduction pathways over mixed-anion chalcohalide photocatalysts.

Carbon is the element that makes up the major fraction of lipids and carbohydrates, which can be used for making biofuel. It is therefore important to provide enough carbon and also to follow the flow into particulate organic carbon and potential loss to dissolved organic forms of carbon. Here, we present methods for determining dissolved inorganic carbon, dissolved organic carbon, and particulate organic carbon.

Phosphorus (P) is a macronutrient for all microalgal species, and the main form of uptake is orthophosphate (PO4). In this chapter we present a colorimetric method for determining the PO4 concentration and dissolved organic phosphorus (DOP) based on total phosphorus (TP) measurements. We also describe a method for determining particulate organic phosphorus (POP) based on the same principles.

The effects of anaerobic digestates on soil microbial communities have received increasing attention due to their potential impacts on soil health and antibiotic resistance. To date, no integrated analysis of rhizosphere bacterial community structure, antibiotic resistance genes (ARGs), and mobile genetic elements has been conducted in digestate-treated perennial ryegrass (Lolium perenne L.). We analyzed rhizosphere bacterial communities of this pasture using metabarcoding to study the effects of a manure-derived digestate on community structure and predicted functions. We also explored the association between digestate-enriched taxa and explanatory variables, including the abundance of two ARGs, class 1 integrons, and IncP-1ε plasmids. The greenhouse study included an unfertilized control and three fertilization treatments: digestate, inorganic fertilizer, and combined fertilizer (digestate + inorganic fertilizer). The results indicated a significant effect of the fertilizer type on bacterial communities and a stimulation of predicted functions related to genetic information processing by digestate and its combination. Digestate application resulted in the greatest differentiation in bacterial community structure relative to the unfertilized control and shifted communities toward amplicon sequence variants (ASVs) positively associated with class 1 integrons. Differential abundance analysis identified three ASVs and three genera (Arenimonas, Algoriphagus and Novosphingobium) that were significantly enriched under digestate treatment, relative to both urea and the unfertilized control. Our results demonstrate that anaerobic digestate application alters bacterial community structure and highlight the need for further studies to elucidate the potential adaptive role of class 1 integrons in rhizosphere microbiomes following digestate fertilization, including their contribution to antibiotic resistance.

Coordination-driven self-assembly offers a powerful toolkit for constructing sophisticated functional architectures. Rigid ligands are widely employed as building blocks in metallo-supramolecular chemistry due to their structural predictability during self-assembly. In contrast, flexible building blocks─though capable of offering greater structural diversity and stimuli-responsiveness─are rarely used, as their conformational freedom often complicates structural control. Consequently, the integration of flexible ligands into metallo-supramolecular systems remains underexplored. To address this challenge, we employ a postassembly ligand-exchange approach to construct a series of heteroleptic metallo-supramolecular cuboctahedra incorporating both rigid and flexible ligands. Investigations of chain length dependence reveal that flexible alkyl-diamine incorporation affects cage hydrodynamic size and stability, with optimal stability achieved at 8 units. This combined bottom-up and top-down synthetic approach offers a promising strategy for engineering complex architectures from flexible building blocks for further exploration of chemistry within a confined space.

In this study, the potential protective role of Se(IV) against inorganic Hg-induced cytotoxicity was evaluated in the human neuroblastoma SH-SY5Y cell line using inductively coupled plasma mass spectrometry, both in conventional (ICP-MS) and single-cell (scICP-MS) modes. To this end, Se (25, 50, and 70 μmol Se L-1) was tested against equivalent concentrations of inorganic Hg (25, 50, and 70 μmol Hg L-1) under both co-exposure and pre-treatment conditions. Cell viability assessed using the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), showed that Se (IV) at 25 and 50 μmol Se L-1 significantly attenuated Hg(II)-induced cytotoxicity, with pre-treatment demonstrating greater efficacy than co-exposure. Additionally, a chemical speciation model was applied to estimate the effective concentrations of Hg and Se available to cells relative to the nominal doses. scICP-MS measurements revealed heterogeneous Hg uptake among individual cells. Notably, co-exposure with 25 μmol Se L-1 reduced cellular Hg accumulation from 73 fg Hg cell-1 to 61 fg Hg cell-1, while pre-treatment further decreased it to 42 fg Hg cell-1. Overall, these findings suggest that selenium mitigates Hg-induced cytotoxicity primarily by reducing intracellular Hg accumulation, highlighting its modulatory role at the single-cell level. By integrating effective concentration modeling with single-cell metal quantification, this work highlights the importance of considering the bioavailable fraction of trace elements in toxicity assessments.

This review article provides an overview of selenium speciation using chromatographic and atomic techniques, based on a survey of relevant studies published in the 21st century. Selenium is an essential element, but the narrow range between deficiency and toxicity makes determining its various chemical forms in many samples fundamental. The total selenium content is insufficient to understand its behavior, as its various species exhibit distinct physicochemical and toxicological properties. In general, organic forms, such as selenomethionine (SeMet) and methylselenocysteine (MeSeCys), are less toxic and more bioavailable than inorganic species and are also associated with beneficial health effects, such as antioxidant activity and potential disease-prevention benefits. Therefore, selenium speciation analysis in various matrices is fundamental to understanding its toxicity, bioavailability, biotransformation, and bioaccumulation, since different chemical species exhibit distinct biological behaviors. Strategies combining chromatographic and atomic detection techniques have been explored for selenium speciation, leveraging separation resolution and detection sensitivity to achieve selective methods with low detection limits and applicability to complex matrices. The most used techniques for speciation include high-performance liquid chromatography (HPLC) and gas chromatography (GC), typically coupled to inductively coupled plasma mass spectrometry (ICP-MS) or other atomic detectors, such as atomic absorption spectroscopy (AAS) and atomic fluorescence spectroscopy (AFS). In addition to reviewing the literature on chromatography-atomic techniques combinations, sample preparation, separation methods, and detectors were discussed. Applications in food, biological, and environmental samples are presented, highlighting the importance of speciation for evaluating selenium toxicity and bioavailability. This review indicates that significant challenges remain due to low analyte concentrations, the risk of interconversion between species, and the emergence of new demands, such as analyzing complex matrices of food, supplements, and biological samples. This shows that Se speciation is a dynamic, continually evolving field essential to analytical chemistry and understanding the effects of selenium on health and the environment.

This chapter will thoroughly examine how the landscape of skin cancer therapeutics is changing with a particular focus on the fact that nanotechnology has resulted in a transformative advancement in drug delivery systems. It starts by providing a summary of the epidemiology of skin cancer, and the treatment difficulties that are associated with conventional modalities, including surgery, radiotherapy, and topical chemotherapy, and their shortcomings. The wide variety of nanocarriers, including lipid-based systems, polymeric nanoparticles, micelles, dendrimers, and inorganic platforms like gold nanoparticles and quantum dots, are then discussed along with their physicochemical properties, the mechanism of improved drug solubility, stability, bioavailability, and targeted activity. The hybrid and stimuli-sensitive delivery systems that are intended to be delivered on the site of action in response to internal (pH, redox, enzyme) or exterior (light, temperature, magnetic field) stimuli receive particular attention. The efforts to optimize therapeutic utility and reduce toxicity in the off-target tissues through enhanced permeability and retention (EPR) impact and ligand-based targeting are among the passive and active tumor targeting mechanisms that are taken into consideration.The chapter ends with a discussion on the recent research, combination therapies, theranostics, and future on clinical translation of nanotechnology-based methods in managing skin cancer.

Polyurea (PUR) electrolytes offer molecular tunability, robust mechanics, and strong Li-salt affinity for lithium metal batteries, but their application is hindered by poor solubility, uncontrolled polymerization, and unstable Li/electrolyte interfaces. Herein, we report two polyurea-based polymerizable monomers with distinct functionalities, DPN and MPN, and construct flame-retardant polyurea gel polymer electrolytes (P-DPN and P-MPN) through an in situ polymerization strategy. This design simultaneously addresses solubility, electrolyte leakage, and interfacial instability. Mechanistic investigations reveal that the carbonyl groups in the urea moieties coordinate with lithium ion (Li+) to homogenize lithium deposition, while the -NH groups interact with anions to induce weakly solvated Li+ structures, thereby accelerating ion transport. Meanwhile, the low HOMO energy level of the polyurea framework promotes the formation of a robust LiF/Li3N-rich inorganic solid electrolyte interphase (SEI), effectively suppressing parasitic reactions and dendrite growth. As a result, the Li||P-MPN||Li symmetric cell exhibits stable cycling for over 2300 h, and full cells paired with diverse cathodes (including NCM811, LCO, and LFP) exhibit outstanding cycling stability under high cathode loading and even at -20°C. This work establishes a molecular design strategy for in situ polyurea electrolytes and deepens the understanding of solvation/interphase regulation in high-performance and safe lithium metal batteries.

The development of sustainable and highly sensitive diagnostic platforms is critical for rapid pathogen identification and effective disease management. Here, a green, magneto-electrochemical biosensing strategy is reported for the selective detection of Streptococcus pneumoniae based on pathogen-specific nuclease activity. Uniform organic-inorganic hybrid polyhedral oligomeric silsesquioxane (POSS) nanoparticles were synthesized via an ultrafast UV-initiated emulsion polymerization within 5 min using an eco-friendly approach. The nanoparticles were sequentially functionalized by in situ deposition of superparamagnetic iron oxide nanoparticles and biomimetic polydopamine coating, enabling robust and high-density immobilization of nuclease-responsive oligonucleotide probes. The resulting PDA@SPION/POSS nanohybrids exhibit controlled size, preserved structural integrity, and strong superparamagnetic behavior, allowing efficient magnetic manipulation and electrochemical signal transduction. Upon exposure to S. pneumoniae, nuclease-mediated probe cleavage produces a pronounced electrochemical response, enabling label-free detection over a wide dynamic range (102-10⁸ CFU mL⁻¹) with a detection limit of 102 CFU mL⁻¹. High selectivity against non-target bacteria highlights the specificity of the enzymatic recognition mechanism. This work establishes a sustainable and amplification-free biosensing platform with strong potential for rapid clinical diagnostics.

The rational use of carbohydrate polymers as functional matrices for integrating inorganic and organic components remains a key challenge in developing sustainable multifunctional materials. Here, a process-oriented, bio-inspired strategy for fabricating a chitosan-centred multifunctional composite coating is presented. This approach uniquely combines plasma-assisted activation of the silk surface, chitosan immobilisation, and subsequent controlled in situ generation of TiO2 nanoparticles in the presence of curcumin, a naturally derived polyphenolic compound. The resulting chitosan/TiO2/curcumin composite system simultaneously imparts antibacterial, UV-shielding, and photocatalytic self-cleaning functions to the silk. Chitosan provides strong antimicrobial activity, maintaining robust bio-barrier antibacterial protection in the composite system and achieving over 99.5% inhibition of Staphylococcus aureus and Escherichia coli growth. Curcumin acts as a TiO2 photosensitiser and charge-transfer mediator, suppressing electron-hole recombination and enabling efficient visible-light-driven photocatalytic activity, as confirmed by accelerated Rhodamine B dye degradation and effective coffee stain removal. Complementary UV absorption by TiO2 (UV-B) and curcumin (UV-A) delivers broad-spectrum UV protection with a UV protection factor of 32.1. Overall, this work demonstrates a distinct carbohydrate polymer-driven fabrication paradigm for engineering high-performance textiles with integrated multifunctional protective properties.

Skin cancer, encompassing non-melanoma types such as squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), and the more lethal melanoma, remains a global health burden. Traditional therapies-including surgery, chemotherapy, radiotherapy, and immunotherapy-often encounter limitations like toxicity, drug resistance, and low specificity. Nanotechnology offers transformative potential by enabling targeted, efficient drug delivery through carriers such as liposomes, dendrimers, and solid lipid nanoparticles (SLNs). These nanocarriers enhance drug solubility, stability, and bioavailability, while passive, active, and stimuli-responsive targeting mechanisms improve precision in delivery. Controlled drug release is governed by diffusion, solvent interaction, degradation, or external triggers such as pH, temperature, and magnetic or electric fields. Lipid-based nanocarriers, including SLNs, liposomes, and nanostructured lipid carriers (NLCs), are particularly effective for poorly water-soluble drugs, allowing dual-phase release and enhanced penetration. Drug-release kinetics can be modeled using equations such as Korsmeyer-Peppas, Higuchi, and zero-order kinetics. Additionally, inorganic nanoparticles (INPs) like gold nanoparticles, carbon nanotubes, and quantum dots offer multifunctional roles in imaging, therapy, and tumor targeting due to their unique physicochemical properties. Photodynamic therapy (PDT) and photothermal therapy (PTT), particularly when enhanced through nanocarriers, offer minimally invasive solutions for melanoma. Formulations using photosensitizers like indocyanine green, chlorin e6, and phthalocyanines have demonstrated improved ROS production and tumor regression. Hybrid systems combining PDT/PTT with targeted delivery and immune modulation further amplify therapeutic outcomes. Overall, nanotechnology represents a promising frontier in skin cancer treatment, offering improved efficacy, reduced side effects, and enhanced precision.

Fluorine incorporation into mixed-anion inorganic solids is often limited by the thermodynamic stability of conventional solid fluorination reagents. LiF, the most used fluorine source in solid-state and mechanochemical synthesis, exhibits strong Li─F bonding that can hinder fluorine transfer and lead to residual LiF and coupled Li/F off-stoichiometry. Here, we investigate fluorinated graphite (CFx) as an alternative fluorine source for the mechanochemical synthesis of lithium metal oxyfluorides. Owing to the heterogeneous nature of C─F bonding in CFx, mechanochemical activation enables stepwise defluorination and effective fluorine transfer while decoupling fluorine delivery from lithium stoichiometry. Using disordered rock-salt Li2VO2F and Al-substituted Li2V1- xAlxO2F as model systems, we obtain the oxyfluoride active materials with no detectable residual CFx, as confirmed by combined X-ray and neutron diffraction, atomic pair distribution function analysis, and 1 9F solid-state NMR. Electrochemical measurements indicate improved fluorine incorporation relative to LiF-derived analogues, featured by more symmetric charge-discharge behavior and elevated redox potential. These results demonstrate that fluorinated graphite can serve as an effective fluorine source for mechanochemical oxyfluoride synthesis and provide insight into how heterogeneous C─F bonding environments influence fluorine transfer in the solid state.

Zero-dimensional (0D) lead-free metal halides are promising luminescent materials, yet their emission origins remain unclear. Using hybrid-functional first-principles calculations, we clarify the photophysical mechanisms in pristine and ns2/nd10-doped Cs2ZnX4 (X = Cl, Br). We reveal that experimentally observed emissions stem not from self-trapped excitons or isolated dopants but from intrinsic point defects and strongly interacting defect-dopant complexes. In pristine hosts, intrinsic luminescence arises from ligand-to-metal charge-transfer transitions involving halogen vacancies (VCl•, and VBr•). For high-valent ns2 dopants, emissions originate from localized s ↔ p transitions within highly coordinated dopant-interstitial complexes, such as (SbZn + Cli)×. Notably, isovalent Sn2+ exhibits a flat, dual-minima excited-state adiabatic potential energy surface, explaining its anomalous cooling-induced red shift. For nd10 dopants, emissive centers include simple substitutional defects and vacancy-assisted complexes, specifically, the (CuZn + VBr)× complex in Cu-doped systems and the (AgZn + 2VBr)• complex responsible for thermochromic luminescence in Ag-doped systems. Ultimately, this defect-chemistry-driven model demonstrates that abundant intrinsic defects and their coupling with dopants govern the luminescence of 0D zinc-based halides, offering insights for designing high-performance, stable lead-free materials.

The development of stable, environmentally benign, and high-performance perovskite solar cells (PSCs) has increasingly focused on innovative inorganic absorber materials. In this study, we conduct a detailed evaluation of the optoelectronic and mechanical properties of Ca3AsBr3, a promising non-toxic halide perovskite, using density functional theory (DFT) alongside SCAPS-1D simulations. The DFT results indicate that Ca3AsBr3 possesses a direct bandgap of 1.66 eV, along with good mechanical stability and strong optical absorption, making it well-suited for photovoltaic applications. To further investigate device performance, four electron transport layers (ETLs)-WS2, SnS2, CdS, and TiO2 were incorporated into HTL-free FTO/ETL/Ca3AsBr3/Au architecture, allowing analysis of energy band alignment, defect tolerance, and overall efficiency. Among these configurations, the WS₂-based device demonstrated superior performance, achieving a power conversion efficiency (PCE) of 20.50%, with an open-circuit voltage (Voc) of 1.165 V, a short-circuit current density (Jsc) of 20.55 mA/cm², and a fill factor (FF) of 85.64%. Further simulation results highlight that an optimal absorber thickness of 1200 nm, along with reduced bulk and interface defect densities (≤ 10¹⁵ cm⁻³ and ≤ 10¹³ cm⁻²), plays a crucial role in minimizing non-radiative recombination losses and improving charge carrier collection. Overall, this work identifies Ca3AsBr3 as a viable eco-friendly absorber material and emphasizes the importance of ETL optimization in achieving efficient, stable, and scalable PSC devices.

Efficient separation of trivalent minor actinides from lanthanides remains a central challenge in advanced nuclear fuel cycle strategies. Here, we develop a machine-learning-guided ligand design framework to optimize intrinsic Am3+/Eu3+ coordination discrimination under limited availability of experimental stability-constant data. A graph neural network model is trained via stepwise transfer learning and semi-supervised refinement to predict first-step metal-ligand stability constants (logK1) for phenanthroline-derived ligands. The predicted differential descriptor (ΔlogK1) is embedded as a reward to guide constrained molecular generation using a scaffold-preserving generative model. The resulting framework maintains chemical validity and structural diversity while enriching candidate ligands with enhanced predicted intrinsic Am3+/Eu3+ coordination preference relative to literature-reported references. This work demonstrates that coordination-chemistry-informed machine learning enables systematic exploration of ligand chemical space under data-scarce conditions and provides a practical computational screening route for candidate extractants targeting challenging An/Ln discrimination problems.

Two-dimensional (2D) metal-organic frameworks (MOFs) are often subjected to mechanical loading in their applications, and the in-plane elastic modulus E‖ is a critical material property needed to understand and predict the mechanical behaviors of 2D MOFs for improved mechanical reliability and strain engineering of their functional properties. However, the E‖ values of 2D MOFs are largely unknown, even for those with widely used coordination linkers like 1,4-benzenedicarboxylate (BDC), because of the challenges in in-plane mechanical testing imposed by both the extreme dimensionality and the high sensitivity of 2D MOFs to external factors (e.g., e-beams) due to their hybrid organic-inorganic nature. Here we employed atomic force microscopy (AFM) stretching of suspended thin membranes to measure the E‖ of three structurally related, BDC-coordinated MOFs. The 2D Zn3(BDC)3(H2O)2·4(DMF) (DMF = N,N-dimethylformamide) has an E‖ value of 11.2 ± 2.5 GPa, much lower than that of its 3D analog, (DMA)2[Zn3(BDC)4·1.5H2O] (DMA = dimethylammonium) (E‖ = 25.9 ± 6.3 GPa), owing to the absence of interlayer covalent bonding. However, a 2D Mn analog, Mn3(BDC)3·4(DMF), exhibits enhanced in-plane stiffness (E‖ = 25.5 ± 4.9 GPa), likely originating from the strengthened coordination at the nodes. We further compared 2D MOFs to other 2D materials and widely used engineering material systems using a density vs. E‖ Ashby plot. Our results provide indispensable insights into the structure-mechanical property relationship of 2D MOFs to guide material engineering and selection.

Two-dimensional (2D) inorganic materials provide a powerful platform for electronic-structure engineering through precise control of the composition and crystal structure. While cation substitution has been widely exploited in oxide nanosheets, anion engineering remains far less developed, particularly in molecularly thin oxynitride systems with controlled nitrogen doping. Here, we report a generalizable route to nitrogen-doped perovskite oxide nanosheets that overcomes long-standing challenges associated with nitridation and structural instability. Using Dion-Jacobson (DJ)-type perovskite oxynitrides, RbSr2(Nb1-xTax)3O10-yNy, as a model platform, we demonstrate that the combination of cation substitution and nitrogen doping enables systematic modulation of both composition and electronic band structure in 2D perovskites. DJ-type perovskite oxynitrides with substantial nitrogen incorporation can be obtained via an unexpected transformation from pseudo-Ruddlesden-Popper-type phases, induced by alkali metal salt-assisted nitridation followed by simple aqueous treatment, without altering the anion composition. These oxynitrides are subsequently exfoliated into single-layer nanosheets that preserve the perovskite framework and the designed cation stoichiometry. Direct determination of both valence and conduction band edges by combined ultraviolet and inverse photoelectron spectroscopy reveals composition-dependent, nonmonotonic band alignment behavior that cannot be resolved by indirect optical or electrochemical approaches. This work establishes an integrated materials and characterization framework for the rational electronic-structure design in 2D oxynitride nanosheets.

In aquatic environments, the arsenic (As) mobilization from anoxic sediments is an important process affecting water quality and associated health risks, as sediment-bound As can serve as a persistent secondary source to overlying waters and groundwater systems. Dissimilatory arsenate reduction (DAsR) is a key microbial process releasing dissolved As(III), yet the role of inorganic electron donors in this pathway remains poorly constrained. Although hydrogen (H₂) is thermodynamically favorable for arsenate respiration, its role in arsenate reduction in natural sediments remains insufficiently resolved. In this study, hydrogen oxidation coupled to arsenate reduction (HOAsR) was investigated using sediments from an As-contaminated, mining-impacted river system. Microcosm incubations showed that H₂ amendment stimulated As(V) reduction under anoxic conditions. DNA-stable isotope probing combined with metagenomics identified Sulfuritalea, Dechloromonas, and a Moorellia-related lineage as putative HOAsR-associated populations. Corresponding metagenome-assembled genomes encoded both H₂ uptake [NiFe]-hydrogenases and the dissimilatory arsenate reductase gene (arrA). Comparative genome analysis further revealed that ∼75% of arrA-containing genomes harbor H₂ uptake [NiFe]-hydrogenases, suggesting that H₂ oxidation represents a phylogenetically widespread metabolic trait among DAsR bacteria. Analysis of public riverine metagenomes further indicated that HOAsR-associated genetic configurations are broadly distributed across sediment microbial communities. Together, these results indicated that HOAsR is a biologically plausible and geographically widespread potential pathway contributing to arsenic mobilization in anoxic sediments.