Metals

Chromium (Cr) contamination in agricultural soils poses a risk to crop productivity and quality. Emerging nano-enabled strategies show great promise in remediating soils contaminated with heavy metals and enhancing crop production. The present study was aimed to investigate the efficacy of nano silicon (nSi) in promoting wheat growth and mitigating adverse effects of Cr-induced toxicity. Wheat seedlings exposed to Cr (K2 Cr2 O7 ) at a concentration of 100 mg kg-1 showed significant reductions in plant height (29...

Pertechnetate, the most stable form of the radionuclide 99 Tc in aerobic aqueous systems, is a hazardous anion present in nuclear waste. Its high mobility in water makes the remediation of the anion challenging. In the past decade, significant effort has been placed into finding materials capable of adsorbing this species. Here, we present the synthesis and high-resolution crystal structure of the coordination polymer [Ag(2,4'-bipyridine)]NO3 , which is capable of sequestering perrhenate─a pertechnetate surrogate─through anion exchange to form another new coordination polymer, [Ag(2,4'-bipyridine)]ReO4 ...

In this paper, we report an innovative method for synthesizing 1-benzyl-2,4-diarylimidazole utilizing 1-phenylethanone-2-(2-pyridinyl) hydrazine and benzylamine, catalyzed by an I2 /CuI system. This approach represents a significant departure from traditional methods for synthesizing polysubstituted imidazoles; it employs the I2 /CuI catalyst to replace rare metal catalysts, thereby achieving high yields of substitution products (≤85%). This method for the generation of 1,2,4-triimidazole derivatives is characterized by its exceptional chemical selectivity and extensive substrate compatibility...

Designing a high-performing triboelectric novel material with eco-friendly, rapid, and cost-effective synthesis is the future of material research in triboelectric nanogenerators (TENG). We report a mechanochemical ball mill synthesis of a zeolitic tetrazolate framework (ZTF-8) that is isostructural with the well-known zeolitic imidazolate framework ZIF-8. ZTF-8 is extremely stable in water, 0.1 M aqueous acid/base solutions for 75 days at 25 °C, and boiling water (100 °C) for 7 days. Kelvin probe force microscopy and molecular electrostatic surface potential computational analysis exhibited that ZTF-8 has a very high positive surface potential...

Dynamically manipulating the spectra and polarization properties of thermal radiation is the key to counter an infrared polarization imaging system (IPIS) under the different background environments. In this Letter, we propose a phase-change metasurface thermal emitter (PCMTE) composed of vanadium dioxide (VO2 ) dipole antenna arrays to dynamically manipulate polarized radiation spectra in the long-wave infrared (LWIR) region of 8-14 µm. During the thermally induced and reversible insulator-to-metal transition (IMT) in VO2 , by simulating the LWIR images at different polarization angles for the PCMTE and background plates, the PCMTE can realize dynamically tunable LWIR camouflage; then, their degree of linear polarization (DoLP) can be calculated, which can demonstrate that the PCMTE can also achieve dynamically tunable LWIR polarization camouflage at the specific radiation angles and backgrounds...

A terahertz (THz) fan-beam computed tomography (CT) system using a 0.3 THz continuous-wave sheet beam is proposed. The diffraction-free sheet beam expands in a fan shape in only one direction and provides propagation-invariant focal lines and extended the depth-of-field. The fan-beam CT based on this beam is the second-generation THz CT. It breaks the conventional 4-f symmetric structure of THz CT using the parallel beam. The fan-beam THz CT allows for use with a linear array detector, which reduces the time required to collect data...

Two-dimensional (2D) MXenes stand out as promising platforms for surface-enhanced Raman scattering (SERS) sensing owing to their metallic feature, various compositions, high surface area, compatibility with functionalization, and ease of fabrication. In this work, we report a high-performance 2D titanium carbonitride (Ti3 CN) MXene SERS substrate. We reveal that the abundant electronic density of states near the Fermi level of Ti3 CN MXene boosts the efficiency of photo-induced charge transfer at the interface of Ti3 CN/molecule, resulting in significant Raman enhancement...

Transition-metal dichalcogenides (TMDCs), as emerging optoelectronic materials, necessitate the establishment of an experimentally viable system to study their interaction with light. In this study, we propose and analyze a WS2 /PMMA/Ag planar Fabry-Perot (F-P) cavity, enabling the direct experimental measurement of WS2 absorbance. By optimizing the structure, the absorbance of A exciton of WS2 up to 0.546 can be experimentally achieved, which matches well with the theoretical calculations. Through temperature and thermal expansion strain induced by temperature, the absorbance of the A exciton can be tuned in situ...

The power and temperature characteristics of Ø200 µm half-disk microlasers with a half-ring metal contact and high-density InGaAs/GaAs quantum dots are studied. In a continuous wave (CW) mode, the maximal optical power at 20°C was 134 mW, and the maximal CW lasing temperature reached 113°C. In a pulsed regime the maximal optical power of 1.6 W, limited by catastrophic degradation, was achieved. By comparing the CW and pulsed current-voltage characteristics, the dependence of a microlaser temperature on CW pumping current was determined...

The development of fast, efficient, and cost-effective tunable optical filters is a tireless pursuit of the goal in the field of optical signal processing and communications. However, the traditional filters have been limited by their complex structures, slow tuning speed, and high cost. To address this challenge, we present a tunable ultra-narrow bandpass filter, which is fabricated by a metal layer cladded in a high-parallelism and high-precision piezoelectric ceramic for an interlayer. Experimental results show a remarkable full width at half maximum of 51 pm and a fast response time of 800 ns...

Among the metal-free dyes, boron dipyrromethene (BODIPY) has attracted much attention in the solar cell industry due to its thermal stability and tunable electronic and photophysical properties. However, the low power conversion efficiency of dye-sensitized solar cells based on BODIPY has limited their widespread application. Accordingly, different types of structural modifications have already been proposed to improve the photophysical properties of the BODIPY dyes. In this study, we used the strategy of constructing BODIPY-based covalent macrostructures by integrating two BODIPY subunits via a π-linker in linear and cyclic configurations...

High-safety and high-energy-density solid-state lithium metal batteries (SSLMBs) attract tremendous interest in both academia and industry. Especially, composite polymer electrolytes (CPEs) can overcome the limitations of single-component solid-state electrolytes. In this work, a strategy of combining a rigid functional skeleton with a soft polymer electrolyte to prepare reinforced CPEs was adopted. The in situ grown zeolitic imidazolate frameworks (ZIFs) with three-dimensional cellulose fiber skeleton (ZIF-67@CF) and succinonitrile (SN) plasticizer into poly(ethylene oxide) (PEO) together form ZIF-67@CF/PEO-SN CPEs...

Photoassisted catalysis using Ni complexes is an emerging field for cross-coupling reactions in organic synthesis. However, the mechanism by which light enables and enhances the reactivity of these complexes often remains elusive. Although optical techniques have been widely used to study the ground and excited states of photocatalysts, they lack the specificity to interrogate the electronic and structural changes at specific atoms. Herein, we report metal-specific studies using transient Ni L- and K-edge X-ray absorption spectroscopy of a prototypical Ni photocatalyst, (dtbbpy)Ni( o -tol)Cl (dtb = 4,4'-di- tert -butyl, bpy = bipyridine, o -tol = ortho -tolyl), in solution...

Despite the significant achievements in dearomatization and C-H functionalization of arenes, the arene ring-opening remains a largely unmet challenge and is underdeveloped due to the high bond dissociation energy and strong resonance stabilization energy inherent in aromatic compounds. Herein, we demonstrate a novel carbene assisted strategy for arene ring-opening. The understanding of the mechanism by our DFT calculations will stimulate wide application of bulk arene chemicals for the synthesis of value-added polyconjugated chain molecules...

A BBr3 -mediated S-directed ortho C-H borylation of thiobenzamides was developed. A variety of ortho -borylated thiobenzamides were obtained in moderate to good yields with a wide functional group tolerance under simple and metal-free conditions. This transformation provided a convenient and practical route to important functionalized thiobenzamides.

The development of highly efficient catalysts for formaldehyde (HCHO) oxidation is of significant interest for the improvement of indoor air quality. Up to 400 works relating to the catalytic oxidation of HCHO have been published to date; however, their analysis for collective inference through conventional literature search is still a challenging task. A machine learning (ML) framework was presented to predict catalyst performance from experimental descriptors based on an HCHO oxidation catalysts database...

Polyfunctionalized arenes are privileged structural motifs in both academic and industrial chemistry. Conventional methods for accessing this class of chemicals usually involve stepwise modification of phenyl rings, often necessitating expensive noble metal catalysts and suffering from low reactivity and selectivity when introducing multiple functionalities. We herein report dehydrogenative synthesis of N -functionalized 2-aminophenols from cyclohexanones and amines. The developed reaction system enables incorporating amino and hydroxyl groups into aromatic rings in a one-shot fashion, which simplifies polyfunctionalized 2-aminophenol synthesis by circumventing issues associated with traditional arene modifications...

Atomically precise metal nanoclusters (NCs) are emerging as idealized model catalysts for imprecise metal nanoparticles to unveil their structure-activity relationship. However, the directional synthesis of robust metal NCs with accessible catalytic active sites remains a great challenge. In this work, we achieved bulky carboranealkynyl-protected copper NCs, the monomer Cu 13 ·3PF6 and nido -carboranealkynyl bridged dimer Cu 26 ·4PF6 , with fair stability as well as accessible open metal sites step by step through external ligand shell modification and metal-core evolution...

INTRODUCTION: The purpose of this in vitro study was to evaluate the dimensional accuracy, trueness, and precision of vinyl siloxane ether (VSXE) and polyvinylsiloxane (PVS) impression materials using different impression techniques. MATERIAL AND METHODS: A three-dimensional (3D) printed mandibular model with implants and metal rods served as the reference model. Impressions were taken in custom trays, resulting in four groups: PVS-closed-tray, VSXE-closed-tray, PVS-open-tray, and VSXE-open-tray...

Multifunctional carbon-based materials exhibit a large number of unprecedented active sites via an electron transfer process and act as a desired platform for exploring high-performance electroactive material. Herein, we exemplify the holistic design of a heterometallic nanostructured material ( MWCNTs@KR-6/Mn/Sn/Pb ) formed by the integration of metals (Mn2+ , Sn2+ , and Pb2+ ) and a dipodal ligand (KR-6) at the surface of multiwalled carbon nanotubes (MWCNTs). First, MWCNTs@KR-6 was readily synthesized via a noncovalent approach, which was further sequentially doped by Mn2+ , Sn2+ , and Pb2+ to give MWCNTs@KR-6/Mn/Sn/Pb ...