Sulfur Functional Groups Research Articles

Involvement of CN Sites in Solvothermally Engineered Metal-Free Carbon Material From Weed Lantana camara for the Detection of Mercury Ions: Experimental and DFT Insights.

Embarking on a journey to decipher the role of active sites in the detection and removal of toxic mercury(II) ions from polluted water, the surface of thermally engineered biomass derived carbon matrix NC-180 was customized with nitrogen atoms. The HR-TEM and XRD analyses revealed the amorphous nature of Lantana camara derived carbon material with small spherical flakes embedded in it. XPS analysis indicated the presence of pyrrolic, pyridinic, and graphitic N atoms, which was further confirmed by FT-IR analysis. The material shows quenching effect in presence of Hg2+ ions resulting in the "turn off" effect with a detection limit of 7.2 nM. The activity of NC-180 was recovered through "turn on" effect in the presence of L-cysteine. Furthermore, the mystery of binding of mercury(II) ions with N-sites is clarified through its comparison with other materials bearing sulfur and oxygen functional groups designated as AC-180, SC-180, and NSC-180. The conclusive evidence for efficient binding of nitrogen sites in NC-180 with mercury(II) ions is derived from various analyses, including 1H-NMR, FT-IR, XPS, and density functional theory. Notably, sustainability is achieved through utilization of toxic weed L. camara for the preparation of this selective carbon material for detection and adsorption of mercury(II) ions.

Friedel-Crafts Reactivity with Sulfondiimidoyl Fluorides for the Synthesis of Heteroaryl Sulfondiimines.

Sulfur functional groups are ubiquitous in molecules used in the pharmaceutical and agrochemical industries, and within these collections sulfones hold a prominent position. The double aza-analogues of sulfones, sulfondiimines, offer significant potential in discovery chemistry but to date their applications have been limited by the lack of convenient synthetic routes. The existing methods mainly rely on imination of low-valent-sulfur intermediates, or the combination of pre-formed organometallic reagents and electrophilic S(VI)-functionalities. Herein, we describe a Friedel-Crafts-type reaction of sulfondiimidoyl fluorides with (hetero)aryls. This new SuFEx reactivity benefits from broad functional group tolerance, mild reaction conditions, and does not require the use of pre-formed organometallic reagents. The efficient use of unprotected indoles and pyrroles, as well as furan, thiophene and carbocyclic aromatics, further demonstrates the advantages of these reactions. We show that the reactivity of the sulfondiimidoyl fluorides can be tuned by switching the N-substituents, allowing an expansion of the range of coupling partners. The utility of the transformation is exemplified by the synthesis of the sulfondiimine analogue of the HIV-I reverse transcriptase-inhibitor L-737,126.

Effect of substrate concentration on sulfamethoxazole wastewater treatment by osmotic microbial fuel cell: Insight into operational efficiency, dynamic changes of membrane fouling and microbial response

To solve the problems of antibiotic pollution, water resources and energy shortage, an osmotic microbial fuel cell (OsMFC) was adopted innovatively to treat antibiotic wastewater containing sulfamethoxazole (SMX), and achieved SMX removal, water production and electricity generation. Substrate concentration was one of the key factors affecting the performances of OsMFC, but there were few relevant studies This study explored the effect of substrate concentration on system performances, clarified the dynamic changes of membrane fouling under different substrate concentrations, and further revealed the response of microbial communities. The results showed that the stable removal efficiency of SMX exceeded 98.8 % due to the efficient interception of forward osmosis (FO) membrane. Compared with the 1.0 g/L NaAc system, the SMX degradation efficiency and maximum output voltage in the 2.0 g/L NaAc system were only increased by 3.9 % and 6.3 %, respectively. However, the initial water flux decreased by 30.1 % in the 7th cycle due to more serious FO membrane fouling. In addition, there were significant differences in the dynamic formation process of FO membrane fouling. Higher substrate concentration increased the relative abundance of Desulfobacterota and Geobacter. Functional prediction analysis showed that increasing substrate concentration promoted carbohydrate metabolism pathways and relative abundance of sulfur respiration functional groups, thereby improving COD and SMX removal rates. However, the biosynthesis of other secondary metabolites was significantly improved, resulting in increased contents of EPS and SMP, which aggravated membrane fouling. Overall, the system performed better when the substrate concentration was 1.0 g/L. This study would provide certain guidance for the performance optimization and membrane fouling mitigation of OsMFC, thereby promoting its practical application in antibiotic wastewater treatment.

Development of polyfunctionalized biochar modified with manganese oxide and sulfur for immobilizing Hg(II) and Pb(II) in water and soil and improving soil health

Mercury (Hg) and lead (Pb) pose significant risks to human health due to their high toxicity and bioaccumulative properties. This study aimed to develop a novel biochar composite (HMB-S), polyfunctionalized with manganese dioxide (α-MnO2) and sulfur functional groups, for the effective immobilization of Hg(II) and Pb(II) from contaminated environments. HMB-S demonstrated superior adsorption capacities of 190.1 mg/g for Hg(II) and 259.9 mg/g for Pb(II), which significantly surpasses the capacities of unmodified biochar (HB) and biochar functionalized solely with Mn (HMB). Mechanistic studies revealed that the immobilization of these metals by HMB-S involved ion exchange, mineral precipitation, surface complexation, and electrostatic interactions. In soil incubation experiments, HMB-S significantly decreased the levels of extractable Hg(II) and Pb(II) compared to the control, reducing the mobility of these metals and converting 17 % of Hg(II) and 26 % of Pb(II) into less bioavailable residual forms. Pot experiments confirmed that all tested biochar materials (HB, HMB, and HMB-S) promoted spinach growth in contaminated soils, with HMB-S being the most effective at lowering Hg(II) and Pb(II) uptake by plants. Additionally, analysis of soil microbial communities indicated that HMB-S altered community composition and increased the relative abundance of metal-resistant bacteria. These findings highlight the potential of polyfunctionalized biochar HMB-S as an effective remediation strategy for Hg and Pb contamination in soil and aqueous environments.

Pd‐Catalyzed Thiotritylation Cross‐Coupling of Aryl Bromides and Iodides to Access Sulfur Functional Groups

AbstractSulfur‐containing functional groups (SFGs) are increasingly important for modern medicinal chemistry and their large structural diversity provides many opportunities for lead optimization. In an effort to simplify the access to the full set of SFGs, we report herein a versatile strategy utilizing (hetero)aryl trityl sulfides (ArSCPh3) as the common precursors. We developed a mild and high yielding Pd‐catalyzed thiotritylation cross‐coupling methodology to afford ArSCPh3 compounds from (hetero)aryl bromides and iodides. Efficient chemoselective derivatizations provided access to eight different SFGs and sulfur(VI) fluorine exchange (SuFEx) hubs, which open up further downstream derivatizations towards the full set of SFGs. Thereby obtainable sulfur motifs include aryl sulfur pentafluorides (ArSF5), aryl tetrafluoro‐λ6‐sulfanyl chlorides (ArSF4Cl), aryl sulfonimidoyl fluorides (ArS(O)(NR)F), aryl sulfonyl fluorides (ArSO2F), aryl sulfonic acids (ArSO3H), and aryl sulfinyl fluorides (ArSOF), which are all valuable functional groups in modern drug discovery.

Preparation of S-doped biochar with sodium thiosulfate as activator and sulfur source and its highly efficient adsorption for Hg2+

Sulfur-doped biochar (S4BC) was prepared with cherry kernel powder as carbon source, Na2S2O3 as sulfur source and chemical activator. Na2S2O3 can activate biochar through the reaction with carbon, intercalation of alkali metals and the generated gas rushing out of pores, and at the same time, active sulfur atoms are doped into biochar during pyrolysis. The physical and chemical properties of S4BC adsorbent were evaluated by various characterization techniques. The results show that S4BC calcined at 800 °C has huge specific surface area of 959.6 m2/g, developed pore structure, and high content of S (18.84 wt%). Moreover, due to the existence of sulfur and oxygen functional groups, S4BC-800 provides sufficient active sites for the adsorption of Hg2+. According to Langmuir model, the maximum adsorption capacity of S4BC-800 for Hg2+ is 724 mg/g at 313 K, and the adsorption speed is fast with excellent stability and reusability. The microfiltration membrane device based on S4BC-800 can effectively remove the low concentration of Hg2+ in the solution. In this study, a simple method for preparing SBC materials is developed, which is not only of great significance as an adsorbent for Hg2+, but also provides a new choice for the preparation of heteroatom-doped materials.

Molecular simulation of the competitive adsorption of methane and carbon dioxide in the matrix and slit model of shale kerogen and the influence of water

Carbon dioxide enhanced shale gas recovery (CO2-EGR) technology is of great significance for shale gas extraction and carbon dioxide storage in subsurface, which involves the competitive adsorption in shale nanopores. Adsorption comparisons between the kerogen matrix and slit and between the pure gas and gas mixture are conducted in this study. Kerogen matrix and slit models are built with the type II-A kerogen macromolecules and adsorptions of CH4 and CO2 are modelled. It is seen: 1) The gas absolute adsorption increases with its molar fraction while decreases with temperature. The Langmuir pressure for CO2 decreases while that for CH4 increases with their molar fractions. The adsorption selectivity of CO2 over CH4 decreases with the increase in pressure and the CO2 fraction, while it is higher in the matrix than that in the slit. Water significantly reduces the gas adsorption especially for matrix. 2) CO2 has high affinity to the Sulfur and Nitrogen functional groups, while CH4 molecules mainly adsorb on the Sulfur, Nitrogen and Carbon functional groups, While water are strongly bound to the Oxygen functional groups with water cluster formed at high contents. 3) Lower interaction energies are shown in the matrix compared with the slit due to the adsorption superposition, which results in gases preferentially adsorbed in the matrix then on the slit surface in the kerogen slit model. The water interaction energy is lowest due to the hydrogen bond, while the interaction energy of CO2 is much smaller than that of CH4 indicating its adsorption advantage.

In situ constructing of sulfur bedecked ZIF-67 with ultrahigh and selectivity UO22+ immobilization capability from seawater

Uranium, a strategically significant resource, is estimated to contain approximately 4.5 billion tons of unconventional uranium in seawater, which can be extracted as a sustainable fuel source for nuclear power plants. In this work, a sulfur bedecked ZIF-67 (SF@ZIF-67) uranium adsorbent were successfully fabricated by employing a facile hydrothermal sulfur functionalization approach. Sequential batch experiment showed that the SF@ZIF-67 specimen displayed a broader pH response range, exceptional UO22+ harvesting efficiency (Uinitial = ∼5–10 ppm, ∼90.68 %–93.79 %) and ultra-high uranium capture capacity (qmax = 769.23 mg/g). Remarkably, due to the strong affinity between sulfur functional groups and uranyl, the SF@ZIF-67 sample exhibited exceptional selectivity with a Kd value exceeding 104 mL/g even in the presence of diverse interfering ions. Moreover, the SF@ZIF-67 specimen showed a sustained uptake efficiency of 66.61 % with close 104 KdU value in a 3000-fold VO43− system. In natural uranium spiked-seawater (Uinitial = ∼10–1000 μg/L), SF@ZIF-67 can capture ∼21–2484.5 μg/g uranium after 24 h contact. Mechanism analysis confirmed that excellent uranyl fixation ability is attributed to the coordination of sulfur and oxygen terminals with uranyl, as well as the redox processes of S2− and U6+. This hydrothermal functionalization technique offers novel insights into the potential application of MOF materials for uranium extraction from seawater.

Heteroatom sulfur exploration for enhancing MgH2 dehydrogenation: A theoretical and experimental analysis

High operating temperatures and sluggish kinetics constrain the commercial application of magnesium-based hydrogen storage materials. To overcome these drawbacks, this work investigates heteroatom sulfur as a catalyst to improve the dehydrogenation of MgH2 using density functional theory (DFT) and experimental validation. Heteroatom sulfur can influence the dehydrogenation of MgH2 by modulating interfacial carbon-magnesium interactions and substituting surface hydrogen sites. In particular, DFT calculations reveal that sulfur functional groups facilitate charge transfer and significantly reduce the energy barrier of MgH2 by 0.32 eV–1.59 eV. Substitution of sulfur atoms at surface hydrogen sites of MgH2 notably improves dehydrogenation by weakening the Mg–H bond and enabling a sulfur-assisted two-step dehydrogenation mechanism. Experimental results further confirm these theoretical findings. The MgH2/900C–20SO2 sample exhibits that the peak dehydrogenation temperature and the onset dehydrogenation temperature were 19.8 °C and 64 °C lower than that of pure MgH2, and a significant reduction in activation energy from 134.52 kJ mol−1 to 92.12 kJ mol−1. This research provides a comprehensive understanding of the catalytic effects of heteroatom sulfur on MgH2 and offers crucial theoretical and practical insights for the development of more efficient magnesium-based hydrogen storage systems.

Spiro-Bifluorene-Cored Dopant-Free Conjugated Polymeric Hole-Transporting Materials Containing Passivation Parts for Inverted Perovskite Solar Cells.

Two spiro-bifluorene-based dopant-free HTMs (X22 and X23) have been synthesized by facilely condensing spiro-bifluorene diamine with 3,4-ethylenedioxythiophene (EDOT)-5,7-dicarbonyl dichloride and 2,3,5,6-tetrafluoro-terephthaloyl dichloride, respectively. In the X22 molecule, lone pairs of electrons on the sulfur (S) and oxygen (O) functional groups interact with the perovskite materials. The hole mobility (μh) of X22 (3.9 × 10-4 cm2 V-1 S1-) is more than twice that of X23 (1.4 × 10-4 cm2 V-1 S1-). The conductivity (σ0) of X22 is 2.73 × 10-4 S cm-1, which is also higher than that of X23 (2.39 × 10-4 S cm-1). The EDOT moiety benefits the contact angle of CH3NH3PbI3 precursor solutions on HTMs as low as 24°. The X22-based device with an indium-doped tin oxide/hole transport material (HTM)/CH3NH3PbI3/phenyl-C61-butyric acid methyl ester (PC61BM)/bathocuproine/Ag structure achieves a power conversion efficiency (PCE) of 19.18%. The PCE of the device based on X23 containing fluorine is 18.70%, and the contact angle between HTM and the perovskite precursor solution is 32°. The X22- and X23-based devices at ambient temperature (≈25 °C) in N2 retain 86% and 79% of the initial PCE after 150 days. The effect of S, O, and F heteroatoms plays an important role in the side chain modification of HTMs, improving defect passivation in HTM/CH3NH3PbI3 interfaces by multiple functional groups.

Maximizing Thiophene–Sulfur Functional Groups in Carbon Catalysts for Highly Selective H2O2 Electrosynthesis

Maximizing Thiophene–Sulfur Functional Groups in Carbon Catalysts for Highly Selective H₂O₂ Electrosynthesis

Catalytic thiolation-depolymerization-like decomposition of oxyphenylene-type super engineering plastics via selective carbon–oxygen main chain cleavages

As the effective use of carbon resources has become a pressing societal issue, the importance of chemical recycling of plastics has increased. The catalytic chemical decomposition for plastics is a promising approach for creating valuable products under efficient and mild conditions. Although several commodity and engineering plastics have been applied, the decompositions of stable resins composed of strong main chains such as polyamides, thermoset resins, and super engineering plastics are underdeveloped. Especially, super engineering plastics that have high heat resistance, chemical resistance, and low solubility are nearly unexplored. In addition, many super engineering plastics are composed of robust aromatic ethers, which are difficult to cleave. Herein, we report the catalytic depolymerization-like chemical decomposition of oxyphenylene-based super engineering plastics such as polyetheretherketone and polysulfone using thiols via selective carbon–oxygen main chain cleavage to form electron-deficient arenes with sulfur functional groups and bisphenols. The catalyst combination of a bulky phosphazene base P4-tBu with inorganic bases such as tripotassium phosphate enabled smooth decomposition. This method could be utilized with carbon- or glass fiber-enforced polyetheretherketone materials and a consumer resin. The sulfur functional groups in one product could be transformed to amino and sulfonium groups and fluorine by using suitable catalysts.

Highly selective detection and removal of mercury ions in the aquatic environment based on magnetic ZIF-71 multifunctional composites with sufficient chlorine functional groups

The development of both detection and removal technologies for heavy metal ions is of great importance. Most of the existing adsorbents that contain oxygen, nitrogen or sulfur functional groups can remove heavy metals, but achieving both selective detection and removal of a single metal ion is difficult because they bind to a wide range of heavy metal ions. Herein, we selected zeolite imidazolium hydrochloride framework-71 (ZIF-71) with sufficient chlorine functional groups to fabricate magnetic ZIF-71 multifunctional composites (M-ZIF-71). M-ZIF-71 had a large specific surface area, excellent water stability, and good magnetic properties, which made M-ZIF-71 conducive to the separation and recovery of adsorbents and the assembly of electrodes. M-ZIF-71 exhibited high selectivity, wide linear range (1–500 μg/L), and low detection limit (0.32 μg/L) for electrochemical detection of mercury ions (Hg2+). Meanwhile, M-ZIF-71 demonstrated rapid Hg2+ adsorption with a high capacity of 571.2 mg/g and excellent recyclability. The high selectivity for Hg2+ was attributed to the powerful affinity of highly electronegative chlorine and Hg2+. Moreover, XPS spectra demonstrated the interaction between chlorine and Hg2+. This work provides a new inspiration for applications in the targeted monitoring and removal of heavy metal pollution.

An HPLC-ESI-QTOF method to analyze polar heteroatomic species in aviation turbine fuel via hydrophilic interaction chromatography

Aviation turbine fuel is a complex mixture of thousands of compounds. An analytical method using hydrophilic interaction liquid chromatography (HILIC) coupled with electrospray ionization and quadrupole time-of-flight mass spectrometry (ESI-QTOF) was developed for the identification of heteroatomic, polar compounds in aviation turbine fuel. Although compounds containing oxygen, nitrogen, and sulfur functional groups are each found at low levels (<0.1 % by mass) in fuels, their presence can generate significant effects on fuel properties. The HILIC-ESI-QTOF method is a combined separation and detection technique that possesses many advantages including a fast and simple sample preparation—requiring no extraction step therefore ensuring no loss of compounds of interest—and the ability to acquire high-fidelity compound data for chemometric analysis of heteroatomic species in aviation turbine fuel.In the development of the method, it was found that the chromatographic conditions and nature of the injection sample had a significant effect on separation efficiency and repeatability. For a sample dataset optimized using a singular aviation turbine fuel, retention time shift was able to be reduced from 0.4 min to 2.0 % relative standard deviation (RSD) to approximately 0.1 min with RSD of 0.4 % using the newly developed method. In addition, a high number of untargeted molecular features (944) and targeted amines (121) were able to be identified when utilizing optimal method conditions. The specific benefits and limitations of utilizing HILIC techniques with HPLC-ESI-QTOF are also discussed herein. This new method is currently being expanded to include analysis of all heteroatoms and is being applied to real fuel sets. The results of these studies are forthcoming.

Large-Scale Continuous and In Situ Photosynthesis of Hydrogen Peroxide by Sulfur-Functionalized Polymer Catalyst for Water Treatment.

Photocatalytic H2 O2 generation system based on polymer catalyst receives increasing attention in recent years; however, the insufficient charge separation efficiency and low oxygen adsorption/activation capacity severely limit their potential application. In this study, a sulfur (C=S) functionalized polymer catalyst is reported through a green water-mediated and catalyst-free multi-component reactions (MCRs) route. The sulfur functional group endows the polymer with a suitable energy band and facilitates the separation of photogenerated electron-hole pair. The reported polymer achieves a high H2 O2 production efficiency (3132 μmol g-1 h-1 ) in pure water without oxygen aeration. To demonstrate their potential in in situ wastewater treatment, a panel reactor system (20×20 cm) is constructed for large-scale production of H2 O2 , which realizes continuous degradation of emerging pollutants including antibiotics and bisphenol A under natural sunlight irradiation condition. The H2 O2 utilization efficiency of the photo-self-Fenton system using in situ generated H2 O2 is found 7.9 times higher than that of the traditional photo-Fenton system. This study offers new insights in green synthesis and design of functional polymer photocatalyst, and demonstrates the feasibility of panel reactor system for large-scale continuous H2 O2 photocatalytic production and water treatment.

Green approach for the fabrication of dual-functional S/N doped graphene tagged ZnO nanograins for in vitro bioimaging and water pollutant remediation

Dual-functional S/N (sulfur and nitrogen) doped graphene-tagged zinc oxide nanograins were synthesized for bioimaging applications and light-dependent photocatalytic activity. Applying the green synthesis approach, graphene was synthesized from kimchi cabbage through a hydrothermal process followed by tagging it with synthesized zinc oxide nanoparticles (ZnO-NPs). The 2D/0D heterostructure prepared by combining both exhibited exceptional advantages. Comprehensive characterizations such as TEM, SEM, XRD, FTIR, XPS, and UV–Vis spectra have been performed to confirm the structures and explore the properties of the synthesized nanocomposite. The graphene/ZnO-NP composite produced exhibited more intense fluorescence, greater chemical stability and biocompatibility, lower cytotoxicity, and better durability than ZnO NPs conferring them with potential applications in cellular imaging. While tagging the ZnO NPs with carbon derived from a natural source containing hydroxyl, sulfur, and nitrogen-containing functional group, the S/N doped graphene/ZnO heterostructure evidences the high photocatalytic activity under UV and visible irradiation which is 3.2 and 3.8 times higher than the as-prepared ZnO-NPs. It also demonstrated significant antibacterial activity which confers its application in removing pathogenic contaminant bacteria in water bodies. In addition, the composite had better optical properties and biocompatibility, and lower toxicity than ZnO NPs. Our findings indicate that the synthesized nanocomposite will be suitable for various biomedical and pollutant remediation due to its bright light-emitting properties and stable fluorescence.

Acid treatment for enhancing Hg0 removal efficiency of chlorine-loaded biochar: mechanism and kinetic analysis.

Adsorbents modified solely with chlorine have limited effectiveness in removing mercury at high temperatures. This study aims to investigate the influence of various acid (HNO3, H2SO4, and H2O2) loadings on the removal efficiency of mercury from NH4Cl-modified adsorbents. The objective is to develop rice straw carbon adsorbents that are both more efficient and cost-effective. The experiments were conducted on a fixed bed experimental platform, with SEM and BET to observe the physical property changes of the modified char samples. XPS analysis was employed to analyze the effects of oxygen, chlorine, and sulfur functional groups. Additionally, a kinetic model was used to investigate the interaction mechanism between the adsorbent and mercury. The findings demonstrate that co-modification surpasses the use of NH4Cl alone, with the combination of NH4Cl and HNO3 yielding the best results. Co-modification enhances the development of a more refined and compact pore structure on the char surface, promoting the physical adsorption of mercury. Moreover, an increased presence of chlorine and oxygen functional groups is observed on the char surface, particularly in the NH4Cl and HNO3 co-modified samples, further enhancing the chemical adsorption capacity of the char. The results from the kinetic analysis support this conclusion. Furthermore, the adsorption process of Hg0 relies on both external mass transfer and chemical adsorption, with the chemical adsorption process playing a more significant role as the controlling factor.

Nitrogen- and Sulfur-Codoped Strong Green Fluorescent Carbon Dots for the Highly Specific Quantification of Quercetin in Food Samples.

Carbon dots (CDs) doped with heteroatoms have garnered significant interest due to their chemically modifiable luminescence properties. Herein, nitrogen- and sulfur-codoped carbon dots (NS-CDs) were successfully prepared using p-phenylenediamine and thioacetamide via a facile process. The as-developed NS-CDs had high photostability against photobleaching, good water dispersibility, and excitation-independent spectral emission properties due to the abundant amino and sulfur functional groups on their surface. The wine-red-colored NS-CDs exhibited strong green emission with a large Stokes shift of up to 125 nm upon the excitation wavelength of 375 nm, with a high quantum yield (QY) of 28%. The novel NS-CDs revealed excellent sensitivity for quercetin (QT) detection via the fluorescence quenching effect, with a low detection limit of 17.3 nM within the linear range of 0-29.7 μM. The fluorescence was quenched only when QT was brought near the NS-CDs. This QT-induced quenching occurred through the strong inner filter effect (IFE) and the complex bound state formed between the ground-state QT and excited-state NS-CDs. The quenching-based detection strategies also demonstrated good specificity for QT over various interferents (phenols, biomolecules, amino acids, metal ions, and flavonoids). Moreover, this approach could be effectively applied to the quantitative detection of QT (with good sensing recovery) in real food samples such as red wine and onion samples. The present work, consequently, suggests that NS-CDs may open the door to the sensitive and specific detection of QT in food samples in a cost-effective and straightforward manner.

Dye-functionalized carbonaceous interlayer as an efficient lithium polysulfide mediator for high performance lithium-sulfur batteries

Lithium − sulfur (Li–S) batteries with their high theoretical energy density and abundant resources have been considered as a promising candidate for next-generation energy storage systems. Nonetheless, undesirable diffusion of lithium polysulfides (LiPSs) toward the lithium metal anode in electrolytes during discharge/charge cycles of Li–S batteries, which is known as shuttle behavior of LiPSs, degrades the long-term stability of Li–S batteries and limits their practical applications. Herein, we present dye-functionalized carbonaceous interlayer, in which organic dye containing nitrogen and sulfur functional groups are incorporated into the carbon matrix of a graphitic layer via hydrothermal process. The introduction of such functional interlayer in Li–S batteries reveals that the carbon matrix with various heteroatom moieties can create physically/chemically favorable active sites for trapping LiPSs and enhance LiPSs conversion toward insoluble products of Li2S/Li2S2, resulting in excellent rate capability and long-term stability with high coulombic efficiency. This study emphasizes the potential of organic dyes functionalization and demonstrates enhanced LiPSs conversion and long-term stability of Li–S batteries.

Combined Surface-Enhanced Raman and Infrared Absorption Spectroscopies for Streamlined Chemical Detection of Polycyclic Aromatic Hydrocarbon-Derived Compounds.

Polycyclic aromatic hydrocarbons (PAHs) constitute a class of universally prevalent carcinogenic environmental contaminants. It is increasingly recognized, however, that PAHs derivatized with oxygen, sulfur, or nitrogen functional groups are frequently more dangerous than their unfunctionalized counterparts. This much larger family of chemicals─polycyclic aromatic compounds─PACs─is far less well characterized than PAHs. Using surface-enhanced Raman and IR Absorption spectroscopies (SERS + SEIRA) combined on a single substrate, along with density functional theoretical (DFT) calculations, we show that direct chemical detection and identification of PACs at sub-parts-per-billion concentration can be achieved. Focusing our studies on 9,10-anthraquinone, 5,12-tetracenequinone, 9-nitroanthracene, and 1-nitropyrene as model PAC contaminants, detection is made possible by incorporating a hydroxy-functionalized self-assembled monolayer that facilitates hydrogen bonding between analytes and the SERS + SEIRA substrate. 5,12-Tetracenequinone was detected at 0.3 ppb, and the limit of detection was determined to be 0.1 ppb using SEIRA alone. This approach is straightforwardly extendable to other families of analytes and will ultimately facilitate fieldable chemical detection of these dangerous yet largely overlooked environmental contaminants.