Green synthesis of nanoparticles for use in food packaging or biomedical applications is attracting increasing interest. In this study, the effect of the degree of substitution (0.7, 0.9 and 1.2) of a carboxymethylcellulose polymer matrix on the synthesis and properties of silver nanoparticles using melanin as a reductant was investigated. For this purpose, the mechanical, UV–Vis barrier, crystallinity, morphology, antioxidant and antimicrobial properties of the films were determined, as well as the color and changes in chemical bonds. The degree of substitution effected noticeable changes in the color of the films (the L* parameter was 2.87 ± 0.76, 5.59 ± 1.30 and 13.45 ± 1.11 for CMC 0.7 + Ag, CMC 0.9 + Ag and CMC 1.2 + Ag samples, respectively), the UV–Vis barrier properties (the transmittance at 280 nm was 4.51 ± 0.58, 7.65 ± 0.84 and 7.98 ± 0.75 for CMC 0.7 + Ag, CMC 0.9 + Ag and CMC 1.2 + Ag, respectively) or the antimicrobial properties of the films (the higher the degree of substitution, the better the antimicrobial properties of the silver nanoparticle-modified films). The differences in the properties of films with silver nanoparticles synthesized in situ might be linked to the increasing dispersion of silver nanoparticles as the degree of CMC substitution increases. Potentially, such films could be used in food packaging or biomedical applications.

This study explores Ti₃C₂ MXene catalysts for the reaction of α-pinene isomerization to get highly valuable products such as camphene, limonene, and tricyclene.

The aim of this study was to isolate microorganisms with bioremediation potential from soil contaminated with heavy metal compounds, and to analyze the tolerance of these microorganisms to various heavy metal concentrations. In total, 7 bacterial strains were isolated and cultivated. The sensitivity of microorganisms to heavy metals proved to be dependent on the type of medium. The use of liquid media during the 8-hour and 24-hour toxicity tests resulted in reduced tolerance of isolates to the concentrations of selective factors used, relative to culture on solid substrates. In addition, optical density increases in the bacterial cultures have been observed at the highest concentrations of some heavy metals. Briefly, during the 48-hours test 3 strains showed increased optical density values in the presence of 1 mM copper sulfate and 2 strains displayed this ability also in the presence of 1 mM cadmium sulfate and lead nitrate.

Hydrogen is a promising energy source which can replace fossil fuels. Among the methods of generating hydrogen, electrochemical water splitting is distinguished by its high renewability efficiency, sustainability and ability to produce this element without the limitation of geological conditions and scaling devices. However, electrochemical water splitting is thermodynamically unfavourable, especially by its oxidation half-reaction (OER) and commercially available catalysts are expensive and have not-abundant natural resources. Therefore, the design of a new, cheap and easy-to-produce material for the efficient evolution of hydrogen from water splitting (HER) is required to accelerate the kinetics of the OER, reduce the energy requirements and improve the durability of its work. Various new technologies and active materials have recently been developed in electrochemical water splitting for hydrogen production. Among them, depending on the preparation method, chemical composition and the morphology of the electrocatalysts influencing the efficiency of both half-reactions of water splitting are still full of gaps of knowledge. Therefore, in this work, we demonstrate a smart methodology to selectively activate NiMOF-based active material in hydrogen and oxygen evolution reactions by designed electrode fabrication. We demonstrate high-performance electrocatalysts based on Nickel/metal-organic frameworks (NiMOF) fabricated via two routes: A - drop cast on pristine Nickel foam active in OER (flower-like structure), B - Ni foam in situ impregnated by NiMOF during synthesis active in HER (rectangular like structure). It allows for the demonstration of a series of highly efficient and robust electrocatalysts. Furthermore, in-situ studies on structural changes in the active materials have been conducted to reveal the mechanisms of water splitting half-reactions.