Search

It is crucial to develop high-performance catalysts for the degradation of antibiotic pollutants. In this paper, we reported an inverse opal Mn-doped WO3 (IO Mn–WO3) catalyst to effectively activate peroxymonosulfate (PMS) for the degradation of levofloxacin (LVX) under visible light irradiation. The degradation efficiency of this novel photo-Fenton-like system could reach almost 100% for LVX. The catalyst showed good recyclability and stability within five cycles. In addition, the possible degradation pathways, the main reactive oxygen species and the degradation mechanism were systematically investigated in this work. ˙O2− and 1O2 were identified as the main reactive oxygen species in the degradation system. Mn doping can initiate PMS activation and improve charge transfer efficiency, WO3 can promote the reduction of Mn species to make the reaction in the system occur continuously, an inverse opal structure can further enhance light absorption and increase the contact area between the catalyst and the pollutant. This work integrated the Fenton-like catalytic effect and the photocatalytic effect into the designed catalyst for PMS activation and antibiotic degradation, which developed a feasible strategy to improve the degradation performance of Mn-based materials for environmental remediation. [ABSTRACT FROM AUTHOR]

In this paper, a novel Pt/CoP/C photo-electro synergistic catalyst was successfully synthesized by a hydrothermal method combined with phosphorus doping treatment. The addition of Vulcan XC-72R is in favor of effectively preventing agglomeration of active catalytic sites, resulting in more uniform and smaller Pt and CoP nanoparticles. The as-obtained Pt/CoP/C shows excellent photo-electro catalytic performance for the HER with simulated solar light irradiation. The optimal hydrogen production is 5384.18 mmol h−1 g−1, which is obviously higher than that of the commercial catalyst (20 wt% Pt/C: 4608.52 mmol h−1 g−1). The research results show that introducing cobalt phosphide into the Pt catalyst can improve the electrocatalytic activity and stability for the HER; in particular, the existence of Co3O4 in Pt/CoP/C leads to an efficient photo-electro catalysis under irradiation, which significantly improves the catalytic activity of Pt. The results above provide a novel strategy for the rational design of cost-effective Pt-based composites towards a fast HER. [ABSTRACT FROM AUTHOR]

Phenolic compounds are ubiquitous in nature because of their unique physical and chemical properties and wide applications, which have received extensive research attention. Phenolic compounds represented by tannic acid (TA) play an important role at the nanoscale. TA with a polyphenol hydroxyl structure can chemically react with organic or inorganic materials, among which metal–phenolic networks (MPNs) formed by coordination with metal ions and polyphenol derivatives formed by interactions with organic matter, exhibit specific properties and functions, and play key roles in photo(electro)catalysis. In this paper, we first introduce the fundamental properties of TA, then summarize the factors influencing the properties of MPNs and structural transformation of polyphenol-derived materials. Subsequently, the functions of MPNs and polyphenol derivatives in photo(electro)catalysis reactions are summarized, encompassing improving interfacial charge carrier separation, accelerating surface reaction kinetics, and enhancing light absorption. Finally, this article provides a comprehensive overview of the challenges and outlook associated with MPNs. Additionally, it presents novel insights into their stability, mechanistic analysis, synthesis, and applications in photo(electro)catalysis. [ABSTRACT FROM AUTHOR]

In this paper, we compare the reactivity of a series of triaryl borates B(OArx)3 as catalysts for the hydroboration of alkenes and alkynes. It was observed that commercially available B(OPh)3 performed the poorest, whereas catalysts with o-F atoms appeared to perform much better. [ABSTRACT FROM AUTHOR]

The low efficiency of protease hydrolysis on wool keratin limits the development of protease-based wool shrink-proofing finishing. In this paper, a highly efficient protease catalytic system consisting of a trihydroxy organ phosphine compound and the protease Savinase 16L was used for wool shrinkproofing treatment by multiple padding. The directional friction effect, area shrinkage, fineness, and strength of wool samples were measured. Scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, zeta potential, and amino acid analyses were used to characterize the structure of the wool samples. Additionally, the dyeing properties of the treated wool were also investigated. The results showed that the hydrolysis of wool fiber scales using the protease catalytic system was an uneven process from point to surface. The padding treatments could promote a synergistic process of biochemical keratin degradation and physical scale removal, improving the efficiency and uniformity of the reaction. The area of the treated wool sample shrank by 1.65% after the TM31 5 x 4N test, while the tenacity decreased by 9.69%. The isoelectric point of the treated fiber increased from 4.37 to 6.09. Under dyeing conditions, the positively charged surface of the treated wool increased, which significantly increased the adsorption rate of the fiber for negatively charged dyes. In addition, the increase in the surface roughness and surface dyeing seat resulted in a significant increase in the color depth of the treated wool fibers after dyeing. This study provides a feasible route for the industrial application of the protease method for the shrink-proofing treatment of wool. [ABSTRACT FROM AUTHOR]

Promoting the separation of photoelectrons and holes can enhance the photocatalytic performance of photocatalysts. The combination of photocatalysts with piezoelectric materials is an effective way to improve the photocatalytic performance. In this paper, the heterogeneous structure of PZT/Ag2O is proposed, which can effectively improve its photocatalytic degradation performance through the piezoelectric effect. RhB degradation experiments were conducted under ultrasonic vibration and visible light irradiation to evaluate the photocatalytic performance of PZT/Ag2O. It is worth noting that PZT/Ag2O showed excellent piezo-/photocatalytic activity, and the degradation rate of RhB within 60 min was 96.31%, which was higher than those achieved under ultrasonic vibration (55.98%) and visible light irradiation (65.14%). The improved performance is due to the heterojunction construction widening the optical response range, while the piezoelectric effect provides a built-in polarization field to improve the separation efficiency of photogenerated electrons and holes. This study provides an efficient and feasible piezo-/photocatalyst for the treatment of pollutants. It is helpful to understand the mechanism of the piezoelectric effect and improve the photocatalytic performance. [ABSTRACT FROM AUTHOR]

For a knowledge-based design of enzyme catalysis in deep eutectic solvents (DESs), the influence of the DES properties (e.g., water activity and viscosity) and the impact of DESs and their individual components must be assessed. This paper investigates three different DESs: choline chloride–glycerol (ChCl–Gly), choline chloride–ethylene glycol (ChCl–EG), and ethyl ammonium chloride–glycerol (EACl–Gly). The specific activity and half-life time of horse liver alcohol dehydrogenase (HLADH) were experimentally determined in these DESs with water contents ranging from 0%–100%. HLADH showed limited activity in neat DESs, which was enhanced by adding water. Experiments with individual DES components of ChCl–Gly were carried out to clarify their individual influence. Glycerol acts as a strong stabilizer for the enzyme, whereas choline chloride's results are deleterious. To understand the experimental findings, molecular dynamics (MD) simulations were carried out to quantify the solvation layer and calculate the spatial distribution of the solvent molecules around HLADH. The experimental and the in silico approach suggests that designing novel DESs with higher glycerol loadings would result in improved media for biocatalysis. This is demonstrated by performing the reduction of cinnamaldehyde to cinnamyl alcohol—a relevant compound for the food industry and cosmetics—in ChCl–Gly (1 : 9 molar ratio), with 20 vol% water to decrease the viscosity. HLADH is highly active and stable under these new conditions, giving promising productivity (15.3 g L−1 d−1). This paper demonstrates that DESs can be designed to be both substrate-solubilizers and enzyme-compatible, opening new research lines for green chemistry and biocatalysis. [ABSTRACT FROM AUTHOR]

This paper describes iron/photoredox dual-catalyzed acyl nitrene formation and the use of acyl nitrene in constructing various C–O bonds towards phthalides. The developed reaction starts from N-methoxyl-2-alkylbenzamides. Mechanism surveys suggest the reaction involves iron nitrene-based hydrogen atom abstraction (HAA), radical-polar crossover and O-nucleophilic SN1. Distinctively, the often-reported radical rebound in previous publications is not observed. The reaction represents the first example on acyl nitrene-based synthesis of phthalides. Moreover, it also serves as a supplement for the synthesis of marketed medicines such as 3-butylphthalides (NBP), thalidomide, Pomalyst and Otezia. [ABSTRACT FROM AUTHOR]

The synthesis of three N-heterocyclic carbene complexes by stepwise grinding is described in this paper. The benzimidazolium salts ([H2L]Br2 and [H2L](PF6)2 ([H2L] = 1,1′-di(2-picolyl)-3,3′-methylenedibenzoimidazolium)) were initially prepared. Their reactions with Ni(OAc)2·4H2O by grinding afforded three nickel complexes, [NiL]Br2·CH3OH (1), [NiL]Br2·2H2O (1′) and [NiL](PF6)2·0.5CH3CN (2), respectively. A five-coordinated complex [NiLBr]PF6 (3) was further obtained by grinding NH4PF6 with complex 1 or 1′, or grinding KBr with complex 2. Complex 3 can also be obtained by direct grinding of complexes 1/1′ and 2. Complex 3 was subsequently used as a catalyst in the C–S bond cross-coupling of 2-bromoacetophenone and 2-mercaptobenzothiazole. The entire procedure from the synthesis to the catalytic reaction was performed by mechanochemistry. The green metrics E-factor and EcoScale close to ideal values showed the eco-friendly nature of the entire procedure. [ABSTRACT FROM AUTHOR]

Chiral ligands are of particular importance in asymmetric transition-metal catalysis. Although the development of effective chiral monodentate N-heterocyclic carbenes (NHCs) has been slow, a growing amount of papers have been published in recent years showing their unique efficiency as chiral ancillary ligands. Herein we provide an overview of NHC structures that accomplish high levels of enantioselectivity (≥90% ee) and give guidelines to their use and thoughts on the future of this field. [ABSTRACT FROM AUTHOR]

Developing an efficient signal amplification strategy is very important to improve the sensitivity of bioanalysis. In this paper, a liposome-assisted enzyme catalysis signal amplification strategy was developed for electrochemiluminescence (ECL) immunoassay of prostate specific antigen (PSA) in a split-type mode. The sandwich immunoreaction occurred in a 96-well plate, and glucose oxidase (GOx) encapsulated and antibody-modified liposomes were used as labels. The ECL detection was carried out using a rGO-Au NP modified glassy carbon electrode (GCE). The large amount of generated H2O2, i.e. the coreactant of the luminol system, and the excellent catalytic behavior of rGO-Au NPs greatly boosted the ECL signal, resulting in the signal amplification. The developed ECL immunosensor for detecting PSA achieved a wider linear range from 1.0 × 10−13 to 1.0 × 10−8 g mL−1 and a detection limit of 1.7 × 10−14 g mL−1. The application of the proposed strategy was demonstrated by analyzing PSA in human serum samples with recoveries from 89.0% to 113.0%, and relative standard deviations (RSDs) were less than 6.6%. This work provides a new horizon to expand the application of liposomes for ECL bioanalysis. [ABSTRACT FROM AUTHOR]