Nitrogen-Doped Nanoporous Carbons for Selective Separation of Ar/Kr/Xe/Rn Gases: An Experiment-Based Simulation Study

It is still a challenge to find high-efficiency adsorbents for the separation of noble gases. In this work, we combine the grand canonical Monte Carlo (GCMC) simulation and adsorption integral equation to theoretically characterize the pore size distribution (PSD) of experimentally synthesized nitrogen-doped nanoporous carbon (Carbon-ZX) and further predict the selectivity of Carbon-ZX for Xe/Kr, Xe/Ar, and Rn/N₂ mixtures. Results indicate that the selectivities of Carbon-ZX for Xe/Kr and Xe/Ar apparently are greater than that of other MOFs in the same conditions, which also is further confirmed by Henry’s constant and isosteric adsorption heat. Moreover, the Carbon-ZX for the Rn/N₂ binary mixture shows the extremely high selectivity (about 800–1200) in the molar fraction <i>X</i>_Rn < 0.001, which means that Carbon-ZX is a promising candidate for indoor Rn capture. In short, this work provides a useful method to characterize the experimentally synthesized nanoporous materials and further explores their applications in adsorption and separation

Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode

The objective of this study was to systematically investigate the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA), which are problematic lignocellulose-derived byproducts, on exoelectrogenesis in the bioanode of a microbial electrolysis cell. The five compound mixture at an initial total concentration range from 0.8 to 8.0 g/L resulted in an up to 91% current decrease as a result of exoelectrogenesis inhibition; fermentative, nonexoelectrogenic biotransformation pathways of the five compounds were not affected. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. All five parent compounds contributed to the observed inhibition of the mixture. The IC₅₀ (i.e., concentration resulting in 50% current decrease) of individually tested parent compounds was 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. However, the parent compounds, when tested below their respective noninhibitory concentration, jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products, inhibited exoelectrogenesis only at high concentrations, but to a lesser extent than the parent compounds. Exoelectrogenesis recovery from inhibition by all compounds was observed at different rates, with the exception of catechol, which resulted in irreversible inhibition

Design of the Alkali-Metal-Doped WO₃ as a Near-Infrared Shielding Material for Smart Window

Development of new WO₃-based material is significantly important for smart-window applications. In this work, the electronic properties of alkali metals monodoped (A_0.083WO₃, A = Li, Na, K, Rb, and Cs) and codoped (Li_0.083A_0.083WO₃, A = Li, Na, K, Rb, and Cs) hexagonal WO₃ (hex-WO₃) were investigated by employing the hybrid functional method. It is found that codoping is more stable than monodoping except in the case of (Li, Li). In the monodoped and codoped systems, the Fermi level moves into the conduction band and shows metal-like characteristic, which is responsible for the optical absorption in the visible light and NIR absorption range. In addition, the codoped systems exhibit strong NIR absorption which is not found in the pure hex-WO₃. Our results show that (Li, Cs) codoped hex-WO₃ is the most stable among these systems, showing excellent NIR-shielding property, which is promising for energy-saving smart-window applications

Synthesis of Cyano-Containing Phenanthridine Derivatives via Catalyst‑, Base‑, and Oxidant-Free Direct Cyanoalkylarylation of Isocyanides

An efficient catalyst-, base-, and oxidant-free direct cyanoalkylarylation of isocyanides with AIBN has been developed under mild conditions. This strategy provides an elusive and rapid access to a wide range of cyano-containing phenanthridine derivatives in good yields via a one-pot alkylation/cyclization radical-cascade process. The mild reaction conditions together with no need of any catalyst, base, or oxidant make this protocol environmentally benign and practical

N‑Heterocyclic Carbene/Lewis Acid Catalyzed Enantioselective Aerobic Annulation of α,β-Unsaturated Aldehydes with 1,3-Dicarbonyl Compounds

A novel and efficient aerobic asymmetric cyclization reaction of cinnamaldehydes and 1,3-dicarbonyl compounds through oxidative NHC-catalysis has been developed, and it allows the synthesis of a wide range of enantiomeric enriched dihydropyranone derivatives in good yields with good to excellent enantioselectivities. Various α,β-unsaturated aldehydes with aliphatic and aromatic substitution groups and 1,3-dicarbonyl compounds were well tolerated. The air was directly used as the oxidant, which made this asymmetric cyclization reaction in a highly efficient, cheap, and green manner

Computer Screening of Dopants for the Development of New SnO₂‑Based Transparent Conducting Oxides

Transparent conducting oxides (TCOs) are unique materials with high electrical conductivity and optical transparency and have been extensively used in optoelectronic devices. However, the prototype n-type TCO, Sn-doped In₂O₃ (ITO), is limited by the rarity and high cost of indium. In contrast, SnO₂ is a promising alternative candidate, which is a low-cost and nontoxic material and also exhibits electrical and optical properties, compared to those of ITO. Here, we present a first-principles-based computer screening system to search for suitable dopants for monodoping or codoping SnO₂ to develop new SnO₂-based TCO materials. The screening is based on an efficient and reliable way of calculating the effective mass, the band gap, the formation energy, and the binding energy. The outcomes of the screening include all already known successful SnO₂-based TCO materials (Sb-doped SnO₂, ATO; F-doped SnO₂, FTO) and also some new ones (P-doped SnO₂, PTO; F and P codoped SnO₂, FPTO), which would be hopeful materials of interest for further experimental validation

Rapid Access to Spirocylic Oxindoles: Application of Asymmetric N‑Heterocyclic Carbene-Catalyzed [3 + 3] Cycloaddition of Imines to Oxindole-Derived Enals

A chiral N-heterocyclic carbene (NHC)-catalyzed [3 + 3] cycloaddition reaction of imines and oxindole-derived enals was developed for rapid access to spirocylic oxindoles. In most cases, the desired spirocylic oxindole products were obtained in high yields and excellent enantioselectivities with less than 1 h of reaction time

Enantioselective Construction of Spirocyclic Oxindole Derivatives with Multiple Stereocenters via an Organocatalytic Michael/Aldol/Hemiacetalization Cascade Reaction

An efficient organocatalytic Michael/aldol/hemiacetalization cascade reaction for construction of enantioenriched spirocyclic oxindoles fused with tetrahydropyrane has been developed. The desired highly functionalized 5′,6′-dihydro-2′<i>H</i>,4′<i>H</i>-spiro­[indoline-3,3′-pyran]-2-one derivatives containing multiple stereogenic centers were obtained in moderate to high chemical yields and with high stereoselectivities

Fabricating Transparent Multilayers with UV and Near-IR Double-Blocking Properties through Layer-by-Layer Assembly

We have fabricated a transparent composite film with UV and near-infrared (near-IR) double-blocking properties using polyethyleneimine (PEI), indium tin oxide (ITO), and zinc oxide (ZnO) through layer-by-layer (LbL) assembly under an ultrasonic field. By applying ultrasonic-assisted LbL assembly, the aggregation of nanoparticles has been excluded, resulting in a flatter and more transparent (visible range) film than that obtained under conventional LbL assembly. Moreover, the effects of the ultrasonic field are discussed in terms of the fact that the transformation between the states of PEI/ITO films assembled with or without ultrasonic field was reversible. To enhance the UV-blocking properties in the most damaging region (290–350 nm), we incorporated ZnO nanoparticles, which can block UV rays below 350 nm, and the obtained hybrid multilayer displayed a high transparency of over 85% (visible range) and good UV-/near-IR double-blocking effects that shielded nearly 80% of the UV rays under 350 nm and 80% of the IR radiation above 1600 nm

Enantioselective Construction of Spirocyclic Oxindole Derivatives with Multiple Stereocenters via an Organocatalytic Michael/Aldol/Hemiacetalization Cascade Reaction

An efficient organocatalytic Michael/aldol/hemiacetalization cascade reaction for construction of enantioenriched spirocyclic oxindoles fused with tetrahydropyrane has been developed. The desired highly functionalized 5′,6′-dihydro-2′<i>H</i>,4′<i>H</i>-spiro­[indoline-3,3′-pyran]-2-one derivatives containing multiple stereogenic centers were obtained in moderate to high chemical yields and with high stereoselectivities