Amount Of Precursor Research Articles

Synthesis of Monodisperse and Discrete Ultra-High Nickel LiNi0.97Co0.02Mn0.01O2 Octahedral Single Crystals via Single Crystal Intermediates for Li-Ion Batteries.

Micrometer-sized single crystal cathodes have garnered significant interest as promising cathode materials for lithium-ion batteries due to their ability to reduce surface area exposure to electrolytes and suppress side reactions, thereby enhancing electrochemical performance. One of the challenging issues with single crystal cathode materials is synthesizing monodisperse and discrete single crystals rather than agglomerated quasi-single crystals. However, conventional solid-state synthesis of most single crystals results in severe agglomeration and cation mixing, as it requires high temperatures to promote particle growth to several micrometers. In this study, a novel morphology-conserving reaction strategy that employs octahedron single crystal intermediates is introduced to synthesize discrete, monodisperse LiNi0.97Co0.02Mn0.01O2 octahedron single crystals. This scalable and cost-effective approach involves using rock-salt Ni0.97Co0.02Mn0.01O1+x octahedrons as single crystal intermediates, which are transformed in unreactive unary lithium salt melts (LiCl and Li2SO4) from spherical Ni0.97Co0.02Mn0.01(OH)2 obtained via coprecipitation. These intermediates are then subjected to a stoichiometric amount of Li precursor in a conventional solid-state synthesis to produce layered LiNi0.97Co0.02Mn0.01O2. This process is a morphology-conserving lithiation reaction, leading to the formation of discrete and monodisperse LiNi0.97Co0.02Mn0.01O2 octahedron single crystals. The resultant LiNi0.97Co0.02Mn0.01O2 single crystals demonstrate superior electrochemical performance, including stable capacity retention over 150 cycles, which surpasses that of typical quasi-single crystals produced through conventional methods. This is attributed to negligible crack formation during cycling, in contrast to significant cracking observed in conventional quasi-single crystals. This implies that single-crystal forms are preferred over agglomerated quasi-single crystal forms for enhancing cycle performance. These findings provide valuable insights into the industrial synthesis of discrete and monodisperse ultrahigh-nickel oxide cathode materials.

Straightforward Synthesis Methodology for Obtaining Excellent ORR Electrocatalysts From Biomass Residues Through a One Pot‐High Temperature Treatment Approach

AbstractMaterials prepared from biomass residues are potential candidates to substitute the Pt‐based commercial electrocatalysts in oxygen reduction reaction (ORR). Although some investigations have reported activity and durability comparable to Pt/C using biomass‐derived catalysts based on Fe─N─C sites, it remains a challenge to decrease the environmental impact of the production of these materials. A straightforward procedure is developed to obtain excellentORR electrocatalysts from biomass residues which requires a single high‐temperature treatment. The final washing step is avoided by optimizing the initial amount of Fe precursor (FeC2O4). Besides the formation of iron oxide nanoparticles, a highly dispersed Fe phase is detected by High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐Ray Spectroscopy (HAADF‐STEM‐XEDS) analysis as well as graphitic carbon structures. The best performance for almond shell‐based electrocatalysts is achieved for the sample containing 4.6 wt. % of Fe. The procedure developed is also applied to oceanic posidonia and eucalyptus residues, also showing excellent ORR behavior. The best sample is studied in a primary Zn‐air battery (ZAB) obtaining a maximum power density of 59 mW cm−2 and 755 mAh gZn−1 capacity.

Cobalt-Doped Hydrochar Derived from Microalgae as an Efficient Peroxymonosulfate Activator for Paraben Degradation

Hydrochar, an attractive member of the carbonaceous materials, is derived from biomass and projects great potential in peroxymonosulfate (PMS) activation, but has not been studied much. Herein, by using the large-scale cultured Chlorella vulgaris and field-collected bloom algae, a series of porous hydrochar was synthesized via a facile hydrothermal carbonization reaction, while Co doping significantly increased their specific surface areas, carbonization degree, and surface functional groups. These Co-doped hydrochar (xCo-HC, x: amount of the Co precursor) could efficiently activate the PMS, resulting in nearly 100% removal of five common paraben pollutants within 40 min. A dosage of 0.2Co-HC of 0.15 g/L, a PMS concentration of 0.6 g/L, and an unadjusted pH of 6.4 were verified more appropriately for paraben degradation. The coexistence of Cl−, SO42−, and humic acid inhibited the degradation, while HCO3− showed an enhancing effect. No observable change was found at the presence of NO3−. Quenching results illustrated that the produced •SO4− during the conversion of doped Co3+/Co2+ acted as the dominant active species for paraben degradation, while •O2−, 1O2, and •OH contributed relatively less. The algae-based hydrochar potentially facilitated the electron transfer in the xCo-HC/PMS system. Overall, this study develops a new strategy for resource utilization of the abundant algae.

Organic-Inorganic Hybrid Nanoparticles for Enhancing Adhesion of 2K Polyurethane to Steel and Their Performance Optimization Using Response Surface Methodology.

Automakers are focusing on lightweight vehicles to address fuel economy and emission challenges and are using high-performance materials such as 2K PU-based joints as alternatives to cast iron, steel, and other metals. This study was conducted with the aim of expanding the application of 2K PU and enhancing its compatibility with steel substrates, which are commonly used in the automotive manufacturing industry, through the use of O-I hybrid nanoparticles containing alkoxysilane groups as additives in the 2K PU formulation. At the same time, the simplified process introduced and examined in this study demonstrates its feasibility for industrial-scale applications; the process offers notable advantages in reducing workload and curing time by eliminating cumbersome surface pretreatment steps before applying the 2K PU layer. Two types of commercial SB PU and EB PU were selected to study the mechanism by which O-I hybrid NPs enhance adhesion when integrated directly into the 2K PU formulation. We optimized various input parameters through practical work and modeling using the response surface method. These parameters included the amounts of AFAP precursor, APTES, and butylene glycol (BG) and the mixing ratio of O-I hybrid NPs in the formulations of two commercial PUs. The results show that O-I hybrid NPs significantly enhance adhesion, increasing performance on stainless surfaces by up to 2.35 times compared to pristine EB and SB PU. Notably, the SB PU's performance can improve up to 2.5 times according to the RSM predictions, highlighting the substantial impact of O-I hybrid NPs.

AI-powered precursor quantification in atmospheric pressure plasma jet thin film deposition via optical emission spectroscopy

Abstract This study explores the feasibility of using Optical Emission Spectroscopy (OES) for in situ monitoring of Atmospheric Pressure Plasma Jet systems in the deposition of thin films. We identify process parameters to control film properties by machine learning for data analysis. In experiments, the depth of the carrier gas inlet pipe (pipe depth) is a crucial controllable variable that directly affects the amount of precursor, influencing the film’s thickness, sheet resistance, and resistivity. We collected 96 000 spectra while preparing 12 film samples, subsequently measured the properties of the samples, and analyzed the spectral data using Principal Component Analysis (PCA) and seven supervised machine learning models. A high correlation was found between spectral features and film thickness. We divided the spectral data in a single process based on processing time into the first third (F-third) and the last third (L-third). Using the F-third data, the PCA plot clearly indicated a significant difference between the two pipe depths, achieving a mean recognition accuracy of 95.1% with machine learning models. In contrast, using the L-third data, the PCA plot showed a high degree of overlap between the two pipe depths, resulting in a considerable decline in recognition performance. Overall, it is challenging to distinguish the spectra visually due to variations in precursor amounts and dynamic fluctuations in the OES signals, even after averaging. Nonetheless, through the successful application of machine learning, we demonstrated an effective spectral recognition system for monitoring pipe depth, which aids in the timely control of film properties.

Pilot Assessment of Impacts of Ozone and Ozone/Hydrogen Peroxide Treatment on the Fate of Per- and Polyfluoroalkyl Substances and Precursors.

Per- and polyfluoroalkyl substances (PFAS) make up a large class of anthropogenic micropollutants prevalent in wastewater. Oxidative processes commonly used in wastewater potable reuse treatment may affect transformation of PFAS precursors, leading to elevated concentrations of perfluorinated alkyl acids (PFAAs) that are significant health concerns. This work conducted a pilot-scale investigation to assess the influence of ozonation (O3) and ozone/hydrogen peroxide (O3/H2O2) advanced oxidation process (AOP), respectively, on the fate of PFAS in a wastewater effluent subjected to reuse. The study evaluated 40 target PFAS and associated precursors [based on the total oxidizable precursor (TOP) assay] under various treatment conditions, including different ozone doses (1.0-4.0 mg·L-1), H2O2 doses (0-0.20 mg·L-1), and contact time (0-20 min). Results indicated that short-chain (C3-C7) PFAAs dominated in concentrations, while overall PFAA concentrations were elevated by both oxidative treatment processes, particularly after high-dose ozonation treatment. TOP assays revealed that there were considerable amounts of PFAA precursors in the reuse wastewater, and their concentrations were decreased after the oxidative treatment with an increase of some of the PFAAs. This pilot study demonstrated that ozone and ozone-based AOP treatments can have a moderate influence on the transformation of PFAS and increase in PFAA levels under practical conditions.

Effect of alkali dosage and silicate modulus on the deterioration of alkali-activated concrete properties subjected to sodium chloride attack and freeze thaw cycles

The deterioration mechanism of alkali-activated slag-fly ash-steel slag concrete (AAC) under sodium chloride attack and freeze-thaw (SF-T) cycles was investigated through a multi-scale methodology. Results showed that appropriate water glass modulus and higher Na2O dosage increased the compressive strength and salt-frost resistance of AAC. The mass loss in AAC was concentrated in the first 100 SF-T cycles, but PCC increases linearly with the SF-T cycles. The salt-frost resistance of PCC was similar to that of AAC samples Na2O dosage of 5 %. Higher Na2O dosage reduces the amount of unreacted precursor, thus reducing the porosity and improving the pore structure of concrete. However, increasing Na2O dosage has not limited the crack development, and the crack width in AAC was greater than in PCC after SF-T cycles. The porosity and average pore size of the concrete increased after SF-T cycles. Friedel's salt was only present in PCC, and NaCl crystals were observed in AAC.

Automated Synthesis of [11C]PiB via [11CH3OTf]-as Methylating Agent for PET Imaging of β-Amyloid.

Efficient synthesis of precursor from commercially available starting materials and automated radiosynthesis of [11C]PiB using commercially available dedicated [11C]- Chemistry module from the synthesized precursor. [11C]PiB is a promising radiotracer for PET imaging of β-Amyloid, advancing Alzheimer's disease research. The availability of precursors and protocols for efficient radiolabelling foster the applications of any radiotracer. Efficient synthesis of PiB precursor was performed using anisidine and 4-nitrobenzoyl chloride as starting materials in 5 steps, having addition, substitutions, and cyclization chemical methodologies. This precursor was used for fully automated radiosynthesis of [11C]PiB in a commercially available synthesizer, MPS-100 (SHI, Japan). The synthesized [11C]PiB was purified via solid-phase methodology, and its quality control was performed by the quality and safety criteria required for clinical use. The synthesis of desired precursors and standard authentic compounds started with commercially available materials with 70-80% yields. The standard analytical methods were characterized all synthesized compounds. The fully automated [11C]-chemistry synthesizer (MPS-100) used for radiosynthesis of [11C]PiB with [11C]CH3OTf acts as a methylating agent. For radiolabelling, varied amounts of precursor and time of reaction were explored. The resulting crude product underwent purification through solid-phase cartridges. The synthesized radiotracer was analyzed using analytical tools such as radio TLC, HPLC, pH endo-toxicity, and half-life. The precursor for radiosynthesis of [11C]PiB was achieved in excellent yield using simple and feasible chemistry. A protocol for radiolabelling of precursor to synthesized [11C]PiB was developed using an automated synthesizer. The crude radiotracer was purified by solid-phase cartridge, with a decay-corrected radiochemical yield of 40±5% and radiochemical purity of more than 97% in approx 20 minutes (EOB). The specific activity was calculated and found in a 110-121 mCi/μmol range. A reliable methodology was developed for preparing precursor followed by fully automated radiolabeling using [11C]MeOTf as a methylating agent to synthesize [11C]PiB. The final HPLC-free purification yielded more than 97% radiochemical purity tracer within one radionuclide half-life. The method was reproducible and efficient for any clinical center.

X-ray characterization, structural analysis, antibacterial activity, and self-cleaning property of Cu-doped TiO2-SiO2 nanocomposite prepared by sonochemical process

TiO2-SiO2 nanocomposites with different copper (Cu) precursor loadings were prepared by a one-step sonochemical process. The mole ratio of Cu precursor in TiO2-SiO2 composite was varied at 0.004, 0.008, 0.020, and 0.040, respectively. The specific X-ray characterization techniques on crystalline structure, chemical composition, and chemical states of Cu-doped TiO2-SiO2 composite were carried out by X-ray diffraction technique (XRD), X-ray fluorescence (XRF), and X-ray photoelectron spectroscopy (XPS), respectively. Surface morphology and chemical bonding of Cu-doped TiO2-SiO2 composite were monitored by field emission scanning electron microscope (FE-SEM) and Fourier transform infrared spectrophotometer (FTIR). For antibacterial properties, the inhibition zone of antimicrobial activity was investigated by varying amounts of Cu precursors in the TiO2-SiO2 composite. After that, Cu-doped TiO2-SiO2 composite powder with different Cu precursor ratios was mixed in PMMA solution and deposited on glass slides to study the optical property and hydrophilicity by UV-VIS-NIR spectrophotometer and contact angle method. XRD patterns of Cu-doped TiO2-SiO2 nanocomposites show the formation of the main TiO2 anatase phase with the ultrafine particles observed by FE-SEM images. FT-IR spectra of the composites are assigned to the prominent peaks of the Ti-O-Ti and Ti-O-Si bond relating to the TiO2-SiO2 host matrix. Meanwhile, TiO2-SiO2 composites with Cu precursor at 0.004 mol ratio can significantly enhance the antibacterial activity with a large inhibition zone. The contact angle value of Cu-doped TiO2-SiO2 nanocomposite film at 0.040 Cu precursor mole ratio in the TiO2-SiO2 matrix resulted in the optimized composite ratio for achieving a hydrophilic surface on the substrate.

Tuning the shell thickness of N-doped interconnected hollow carbon sphere for the electrochemical sensing of antibiotic drug chloramphenicol.

N-doped hollow carbon spheres (NHCSs) with different shell thicknesses are constructed using various amounts of SiO2 precursor. An interconnected framework with diminished wall thickness ensures an efficient and continuous electron transport which helps to enhance theperformance of NHCS. Improvement of the electrocatalytic performance was shown in the determination of antibiotic drug chloramphenicol (CAP) due to theunique hollow thin shell morphology, ample defect sites, accessible surface area, higher surface-to-volume ratio and ansynergistic effect. Boosted electrocatalytic activity of 1.5 N-doped HCS (1.5 NHCS) was applied to detect CAP with a linear range and detection limit of 1-1150µM and 0.098µM (n = 3), respectively, with superior storage stability and considerable sensitivity. These results suggest that the proposed work can besuccessfully applied to the determination of CAP in milk and water samples.

Sulfur Modified Copper Nitride for Electrochemical CO2 Reduction Reaction

Metallic copper has been attracted attention as efficient catalyst for electrochemical CO2 reduction reaction (CO2RR). However, the activity of the catalyst with a single adsorption site is limited by the imbalance of the intermediate binding energy, so-called “scaling relationship”. [1] Therefore, it is crucial to break the scaling relationship between reaction intermediates in order to increase product selectivity and lower overpotential. One of the candidates to overcome this scaling relationship is metal sulfide. According to the computational study, since sulfur atoms work as an adsorption site, metal sulfide is expected to be a suitable catalyst for CO2RR with multiple adsorption sites.[2] In addition, surface modification by sulfur is also effective approach to enhance product selectivity in CO2RR. Increase of formate (HCOO-) selectivity by sulfur introduction on Cu has been reported in some previous reports.[3]-[5] On the other hand, the repulsion between the oxygen lone pair electrons of the CO2 molecule and the electronic clouds of the surface sulfur atoms become an obstacle on CO2RR.[6] A potential solution to this problem is the construction of sulfide-nitride composite. Because of the difference in electronegativity between nitrogen and metal or sulfur, it is considered that the electronic structure of the metal sulfide is altered to reduce the repulsion between oxygen and sulfur.[7] Based on these backgrounds, it is expected that the CO2RR activity of copper nitride (Cu3N) will be enhanced by sulfur introduction.Here, sulfur modified Cu3N with different amount of sulfur were synthesized by reflux method with some modification of previously reported method.[8] X-ray diffraction pattern and SEM-EDX elemental analysis result indicate that the sulfur ratio increases and copper sulfide (Cu2S) crystal phase appears with the amount of sulfur source precursor. CO2RR activity was evaluated in 0.1M KHCO3 electrolyte, and volcano trend was identified between the amount of sulfur and methane selectivity. Among all the catalysts including pure Cu3N and Cu2S which were synthesized by the same method, 4.2 mol% sulfur containing Cu3N showed the highest methane faradaic efficiency (41.4 %). This faradaic efficiency is more than 10 times higher than that of Cu3N (0.48 %) and Cu2S (1.3 %). This finding offers valuable insights into the sulfur role on the modified catalyst.

Synthesis and structural elucidation of cytotoxic mono and dinuclear rhenium carbonyl complexes bearing bis-{1,3-(imino pyrrolyl)-m-chloro phenyl)} ligand

A mononuclear and dinuclear rhenium tricarbonyl compounds were synthesized by the one-pot condensation reaction of [Re(CO)5Br], pyrrole-2-carboxaldehyde and 4‑chloro-m-phenylene diamine. The mononuclear rhenium tricarbonyl complex containing {3-(imino pyrrolyl)-6‑chloro phenylamine)} ligand (IPP) with formula {[Re(CO)3Br(IPP)], (1), was obtained by refluxing stoichiometric quantities of amine, aldehyde and rhenium metal precursor in methanol solution. Similarly, dinuclear rhenium tricarbonyl compound {[Re(CO)3Br]2(BIPP)], BIPP = bis-{1,3-(imino pyrrolyl)-m-chlorophenyl)}, (2) has been synthesized by refluxing appropriate amounts of aldehyde, and rhenium metal precursor in the presence of one equivalent of amine ligand. Compounds 1 and 2 were characterized by FT-IR, 1H NMR, and UV–Vis spectroscopy, elemental analysis, and mass spectrometry. The luminescence properties of the formed complexes were studied in solution at room temperature, revealing an extended lifetime for the dinuclear complex 2 in comparison to 1. DFT calculations for the optimized structures helped to understand the geometry of the complexes, whereas TD-DFT revealed the vertical transitions responsible for the photophysical properties of the complexes. The cytotoxicity of such complexes against MCF-7 breast cancer has been also reported, revealing a dose-dependent growth inhibition attributed to a DNA-intercalating mode of binding for both complexes. The pronounced effect of the two metals on the cytotoxic studies and lifetime of the excited species were investigated. The greater intercalation ability of the complex 2 in comparison to complex1 obtained from circular dichroism studies also indicates the greater efficacy of Re complex 2.

Scaling up gaseous chlorine dioxide (ClO2) treatment in the cold storage of fresh apples

Novel interventions are needed to mitigate microbial risks, like Listeria monocytogenes, before shipping fresh apples to retail markets. Batch gaseous chlorine dioxide (ClO2) in-storage treatments were conducted to assess the inactivation of Listeria innocua, reduction of spoilage microorganisms, and changes in quality. Gaseous ClO2 was generated using equal amounts of dry precursors inside the modified commercial refrigerator with 82 kg and 330 kg apples for pilot and semi-industrial scale experiments, respectively. A cocktail of L. innocua was spot inoculated on the calyx of fresh Fuji apples and treated with an initial ClO2 input of 1.2 g of each precursor/kg of produce at a pilot scale for 30 d and semi-industrial scale for 90 d. Headspace ClO2 concentrations, temperature, and relative humidity were measured during the batch treatments. Reductions of 1.4±0.2 and 1.2 log CFU/mL of Listeria innocua were achieved by pilot-scale and semi-industrial scale trials, respectively. The presence of spoilage microorganisms was not significantly (P>0.05) impacted, and apples displayed no signs of deterioration. This study confirms that ClO2 can significantly inhibit foodborne pathogens, such as Listeria, during prolonged cold storage and reduce the risk of contamination for apple growers.

Toward Scalable Electrochemical Exfoliation of Molybdenum Disulfide Powder through an Accessible Electrode Design.

Cathodic electrochemical intercalation/exfoliation of transition metal dichalcogenides (TMDs) with bulky tetraalkylammonium-based cations is gaining popularity as it avoids the semiconducting (2H) to metallic (1T) phase transformation in TMDs like molybdenum disulfide (MoS2) and, generally, produces sheets with a larger aspect ratio - important for achieving conformal sheet-to-sheet contact in optoelectronic devices. Large single crystals are typically used as the precursor, but these are expensive, often inaccessible, and result in limited quantities of material. In this paper, a 3D-printable electrochemical cell capable of intercalating gram-scale quantities of commercially available TMD powders is presented. By incorporating a reference electrode in the cell and physically restraining the powder with a spring-loaded mechanism, the system can probe the intercalation electrochemistry, for example, determining the onset of intercalation to be near -2.5V versus the ferrocene redox couple. While the extent of intercalation depends on precursor quantity and reaction time, a high yield of exfoliated product can be obtained exhibiting average aspect ratios as high as 49 ± 44 similar to values obtained by crystal intercalation. The intercalation and exfoliation of a wide variety of pelletized commercial powders including molybdenum diselenide (MoSe2), tungsten diselenide (WSe2), tungsten disulfide (WS2), and graphitic carbon nitride (gCN) are also demonstrated.

Facile modification method for the controlled synthesis of dumbbell-like gold nanoparticles (AuNDBs) for application in detecting glucose using the SERS method

Dumbbell-like nanoparticles, previously known for their excellent light absorption and dispersion, have diverse applications, especially in SERS. Herein, we have explored a fast and novel controlled synthesis approach to achieve a high formation of AuNDBs. Precise control of precursor amounts and seed addition order halted seed growth at the AuNDB formation stage, preventing further elongation into rod-like structures. The AuNDBs were functionalized with 4-mercaptobenzoic acid (4-MBA) to create SERS nanosubstrates and deposited on the glass slide through 3-mercaptopropyl (dimethoxy)methylsilane by the spin-coating technique. The detection of d-glucose was achieved by measuring the signal decrease of the 4-MBA Raman probe molecules on the nanosubstrates at different trace concentrations of the analyte. These novel SERS substrates have the potential to provide an enhancement factor (EF) of 2.41 × 107 and a limit of detection (LOD) as low as 1.17 nmol/L. The electromagnetic field distribution of AuNDBs with many arrangements surrounded by air and d-glucose solutions was also determined by using the finite-difference time-domain technique (FDTD). The FDTD results confirmed that d-glucose on the SERS substrates caused the local electromagnetic field to degrade, resulting in the degree of the Raman signal. Our findings suggest that dumbbell-shaped SERS substrates can effectively detect very low levels of glucose, making them ideal for designing novel anisotropic nanoparticle-functionalized surfaces with ease.

Regulating Lewis Acid‐Base Sites over Fenton System for Enhancing Degradation of Pollutants in Saline and Buffered Wastewater†

Comprehensive SummaryThe saline and buffered environment in actual wastewater imposes higher demands on Fenton and Fenton‐like catalytic systems. This study developed a MoS2 co‐catalytic Fe2O3 Fenton‐like system with controllable Lewis acid‐base sites, achieving efficient treatment of various model pollutants and actual industrial wastewater under neutral buffered environment. The acidic microenvironment structured by the edge S sites (Lewis basic sites) in the MoS2/Fe2O3 catalyst is susceptible to the influence of Lewis acidic sites constructed by Mo and Fe element, affecting catalytic performance. Optimizing the ratio of precursor amounts ensures the stable presence of the acidic microenvironment on the surface of catalyst, enabling the beneficial co‐catalytic effect of Mo sites to be realized. Furthermore, it transcends the rigid constraints imposed by the Fenton reaction on reaction environments, thereby expanding the applicability of commonplace oxides such as Fe2O3 in actual industrial water remediation.

Synergy of atom doping and defect construction in marigold-like Zn3In2S6 for improved photocatalytic hydrogen production

Atom doping and defect construction are effective strategies to enhance the performance of photocatalysts. Herein, zirconium (Zr) doping and sulfur vacancies (Vs) are introduced on marigold-like Zn3In2S6 (Zr-ZIS-Vs) by controlling the amount of sulfur precursors and ZrCl4 via a one-pot hydrothermal process. Remarkably, the optimized Zr-ZIS-Vs catalyst exhibits excellent photocatalytic activity, giving a photocatalytic hydrogen evolution rate of 9.44 mmol g−1 h−1, which is 10.73, 4.39 and 2.37 times higher than pure Zn3In2S6 (ZIS, 0.88 mmol g−1 h−1), Zn3In2S6 with sulfur vacancies alone (ZIS-Vs, 2.15 mmol g−1 h−1), and Zn3In2S6 with Zr doping alone (Zr-ZIS, 3.98 mmol g−1 h−1). The apparent quantum efficiency (AQE) of Zr-ZIS-Vs achieves 27.15 % and 4.90 % at λ = 370 and 456 nm, respectively. Experimental results and theoretical simulations reveal the behavioral mechanisms of the deletion of S atoms and the tendency of Zr to replace In, indicating that the defective and reference strategies can narrow the band gap, provide abundant active sites, enhance the effective transport and separation of photogenerated carriers, and modulate the transfer of active sites to empirical site S atoms to achieve the synergistic thermodynamic and kinetic interactions, which effectively enhances the performance of photocatalytic hydrogen production.

Rapid Electrophilic 211At-Astatination of Trimethylgermyl Arenes.

A set of 211At-astatoarenes were synthesized from corresponding trimethylgermyl arenes with an average radiochemical conversion (RCC) of ca. 50 % for electron-rich and approx. 70 % in case of electron-deficient arenes. Both electron rich and electron poor substrates were successfully radiolabeled at room temperature (RT) using relatively low precursor amounts (0.15 μmol/0.02 mL solvent (7.5 mM)). Ready access to ortho-, para- and meta- astatinated arenes was achievable. Optimized reaction conditions were successfully applied to label a poly (ADP-ribose) polymerase (PARP) inhibitor with a RCC of approx. 50 %. We believe that trimethylgermyl derivatives are a viable addition to the astatination precursor toolbox and facilitate astatination of arenes. The developed labeling method should easily be applicable for productions under good manufacturing practice (GMP).

Two-Dimensional Ultrathin Fe3Sn2 Kagome Metal with Defect-Dependent Magnetic Property.

Two-dimensional (2D) Fe3Sn2, which is a room-temperature ferromagnetic kagome metal, has potential applications in spintronic devices. However, the systematic synthesis and magnetic study of 2D Fe3Sn2 single crystals have rarely been reported. Here we have synthesized 2D hexagonal and triangular Fe3Sn2 nanosheets by controlling the amount of FeCl2 precursors in the chemical vapor deposition (CVD) method. It is found that the hexagonal Fe3Sn2 nanosheets exist with Fe vacancy defects and show no obvious coercivity. While the triangular Fe3Sn2 nanosheet has obvious hysteresis loops at room temperature, its coercivity first increases and then remains stable with an increase in temperature, which should result from the competition of the thermal activation mechanism and spin direction rotation mechanism. A first-principles calculation study shows that the Fe vacancy defects in Fe3Sn2 can increase the distances between Fe atoms and weaken the ferromagnetism of Fe3Sn2. The resulting 2D Fe3Sn2 nanosheets provide a new choice for spintronic devices.

Investigating the effect of the perturbation on emulsion polymerization of polystyrene nanospheres

Polystyrene nanospheres (PS spheres) were prepared by soap-less emulsion polymerization. The polymerization reaction with the monomer styrene was initiated using potassium persulfate under nitrogen injection. By adjusting the amount of precursor and the mixing speed of the stirrer during the polymerization process, PS particles of the expected appropriate size can be obtained. This work focuses on the effect of precursor concentration, reaction conditions and stirrer speed on particle size. Samples (C1–C6) were systematically prepared with varying amounts of K2S2O8 and C8H8. The particle sizes ranged from 69.9[Formula: see text]nm to 364.44[Formula: see text]nm. The calculated K2S2O8 to C8H8 ratio remained approximately constant across the samples. This supports the observed trend where increasing monomer concentration leads to larger particle sizes, indicative of bonded spheres. In addition, a correlation between stirring speed and PS bead size is found, with higher speeds resulting in smaller particles. Transmittance analysis of the filtered and sieved process samples showed that better polymerization conditions could be selected for PS beads up to 220[Formula: see text]nm at a stirring speed of 900[Formula: see text]rpm.