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Nanomaterials are vital in catalysis, sensing, energy storage, and biomedicine and now incorporate multiprincipal element materials to meet evolving technological demands. However, achieving a uniform distribution of multiple elements in these nanomaterials poses significant challenges. In this study, various Cu–Ni compositions were used as a model system to investigate the formation of bimetallic nanoparticles by employing computer simulation molecular dynamics methods and comparing the results with observations from solution-combustion-synthesized materials of the same compositions. The findings reveal the successful synthesis of 12–18 nm bimetallic Cu–Ni nanoparticles with high phase homogeneity, alongside phase-segregated nanoparticles predicted by molecular dynamics simulations. Based on the comparison of the experimental and computational data, a possible scenario for phase segregation during the synthesis was proposed. It includes clustering of the atoms of the same type in an initial solution or the stage of gel formation and further developing segregation during the combustion/cooling stage. The research concludes that early synthesis stages, including particle preformation, significantly influence the phase homogeneity of multiprincipal element alloys. This study contributes to understanding nanomaterial formation, offering insights for improved alloy synthesis and enhanced functionalities in advanced applications.

The current study determines a simple and eco-friendly method for the synthesis of silver nanoparticles using the aqueous extract of Ulva rigidaas a bio-capping agent. The synthesized silver nanoparticles (Ag NPs) were characterized, and their antibacterial properties were examined. The extract of U. rigidacan reduce the silver ions into Ag NPs. The physicochemical properties of synthesized Ag NPs were determined using microscopic and spectroscopic analysis. The UV–Vis absorption peak at 401 nm is evidence of the occurrence of surface plasmon resonance (SPR) of Ag NPs. X-ray diffraction was studied, and the crystalline nature of biosynthesized Ag NPs was confirmed. The average size of U. rigida–mediated Ag NPs was 22.6 nm. The transmission electron microscope shows the monodispersed and spherical-shaped nanoparticles. Furthermore, the synthesized Ag NPs were evaluated against human pathogens such as Pseudomonas aeruginosaand Proteus vulgaris. Bio-fabricated U. rigida–assisted Ag NPs may be helpful in developing new drugs against multidrug resistance pathogens.

A possibility for one-step synthesis of bimetallic CuNi nanopowders in a different ratio of Ni to Cu by solution combustion synthesis technique under normal air atmosphere without any post reduction is reported. The effect of different types of fuels like citric acid and glycine on the combustion process and characteristics of resultant solid products were investigated. XRD results showed the existing of CuNi as a main phase and small amounts of CuO and (Ni,Cu)4N. Determined CuNi particle sizes were in the range of up to 50 nm. Computer simulation was performed using the molecular dynamics method for similar concentration compositions, but in size range of 4.5–5.5 nm, as a result of cooling the system from 1700 K to 300 K. In addition, two types of melting scenario of binary CuNi NPs were studied: 1) heterogeneous melting of monocrystalline Cu and Ni NPs; 2) melting of the crystallization products of binary NPs. Melting temperatures weakly depend on the choice of the above-mentioned melting scenario. However, the nature of subsequent crystallization can be influenced by the initial energy of the system, which is higher for case 1. The characteristic temperatures of phase transitions of melting and crystallization are determined based on the analysis of hysteresis loops of the specific potential part of the internal energy of NPs. The patterns of atomic and structural segregation in binary CuNi NPs were studied.

Graphene (G) and metal-decorated G nanocomposites are among the most promising materials for a wide variety of practical applications, and, therefore, the development of fast and reliable methods for nanocomposite synthesis is an important task. Herein we report the new fast approach for solution combustion synthesis (SCS) of large-area G–metallic nanocomposites in an air atmosphere. The G-based nanocomposites were obtained by a SCS using copper and nickel nitrates, as well as their stoichiometric mixture as the metal source and citric acid as a fuel and carbon source. The G structures started on the catalytic surface of freshly synthesized metallic nanograins during the combustion process and formed large-area free-standing films due to the high-energy and fast synthesis process. We proposed a mechanism of formation of the G-based nanocomposites. The phase compositions, structural features, and magnetization behavior of G@Cu, G@Ni, and G@CuNi nanocomposites are carefully studied and described. G@metal nanocomposites were studied as a material for the creation of a highly effective sensing element of semiconductor gas sensors.

The control of indoor air quality and the detection of toxic gases and volatile organic compounds are important tasks for improving life and work conditions, and are highly demanded in a variety of industrial, agricultural and environmental applications. This requires the development of special gas sensing materials with a high sensing response to a variety of gases of a different chemical nature. Herein we report a study on the synthesis, characterization and investigation of the gas sensing properties of WO3-graphene–Cu composite nanomaterials. The nanomaterials have a closely interconnected defective structure with developed surfaces and are characterized by an enhanced sensing response to CO, NO2and acetone. The composite nanomaterials with WO3crystallite sizes of 13–17 nm were synthesized by a modified sol–gel method, where pre-synthesized graphene@Cu nanopowder, obtained by the solution combustion method, was added into an H2WO4gel before the xerogel formation stage. The graphene@Cu flakes played the role of the centers of WO3crystallite nucleation, leading to the formation of mutually interconnected crystalline structures. The graphene@Cu composite tends to accumulate on the tungsten oxide surfaces, causing the formation of structural defects, influencing the surface energy state and concentration of free electrons. The concentration of defects decreases with the increase of graphene@Cu from 1 to 4 wt%, which also affects the gas sensing properties of the WO3-graphene@Cu composites. The highest sensing response to CO and acetone of 19.7 and 21.4, respectively, were detected for the composite with 1 wt% of graphene@Cu. The composite with 2 wt.% of graphene@Cu additive showed the highest sensing response to NO2.

Groundwater is one of the cleanest natural sources of drinking water available, which, at the same time, often requires deironing – removal of the dissolved iron ions – before the water could be used. In this paper, there are describe the preparation, characterization, and deironing properties of surface-modified refractory chamotte granules, used as active components of fillers for deironing filters. For this research, chamotte surface modification was made by solution combustion synthesis (SCS) approach of an aqueous solution of synthetic iron nitrate and citric acid with the different iron-to-chamotte ratios. An iron-rich precipitate from deironing filters was used as a source of iron for the preparation of a precursor solution. Obtained materials were characterized using diffraction, spectroscopic and microscopic methods. The SCS modification resulted in the formation of layers of hematite Fe3O4nanocrystallites of ~5–15 nm on the surface of refractory chamotte granules. It was shown the effect of the dose of iron nitrate on the absorbed iron oxide species content on the surface of the modified chamotte granules and its influence on the surface and operational characteristics. Pilot-plant deironing tests showed that an increase in the concentration of iron on the chamotte granules surface from 5.8 wt% for unmodified samples, to 19.0, 48.7, and 55.8 wt% for the modified ones, led to the respective increase in the deironing efficiency from 41% to 65%, 73% and 78%, respectively.