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An eco-friendly and low-cost method for synthesizing and capping silver nanoparticles with aqueous extracts of apricot and currant wastes is reported. The chemical profiles of the extracts were analysed using liquid chromatography-mass spectrometry (LC-MS). Total phenolic content and total flavonoid content of extracts were determined. The antioxidant activity of the synthesized nanoparticles was evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl) power assays. Cyclic voltammetry study was performed to determine the reducing ability of the aqueous extract of the black currant and apricot pomaces. Characterization of AgNPs was carried out using energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy. Zeta potential of obtained colloidal solutions varies from −33.41 to −24.23 mV indicating the moderate stability of synthesized nanoparticles. The synthesized nanoparticles efficiently demonstrated a bactericide effect on Escherichia coli.

In pursuit of greener nanoscale research, the utilization of the reductive potency of a common byproduct of food-processing industry, i.e., orange peel, has been researched to prepare "green" silver nanoparticles (AgNPs). e synthesized AgNPs were characterized by UV-Vis spectroscopy, dynamic light scattering, and scanning electron microscopy. e results confirmed that silver nanoparticles were formed at the investigated concentrations of Ag + (0.25-6.0 mmol/L) during 5-10 minutes, at ratio AgNO 3 : extract (mL) � 1 : 1, and at 75°C. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles had a face-centered cubic crystal structure. e zeta potential value for AgNPs obtained was − 21.7 mV, indicating the moderate stability of synthesized nanoparticles. e effect of pH on nanoparticle synthesis has been determined by adjusting the pH of the reaction mixtures. e catalytic effectiveness of the prepared green catalyst, AgNPs, has also been investigated in catalytic degradation of methylene blue (MB) dye. e catalytic degradation reaction under solar irradiation was completed (99%) within 35 min, signifying excellent catalytic properties of silver nanoparticles in the reduction of MB.

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The process of obtaining aqueous solutions of silver nanoparticles with the use of a low-temperature nonequilibrium contact plasma and stabilizing agent—polysaccharide (sodium alginate)—has been examined. The synthesized Ag NPs were characterized by using UV-Vis spectroscopy, dynamic light scattering (DLS), scanning electron microscope (SEM), and XRD analysis. The effect of concentration of Ag+, sodium alginate, duration of processing by plasma discharge, and pH of liquid on the production of silver nanoparticles has been studied. The results demonstrated that synthesis provides the formation of silver nanoparticles for investigated concentrations of Ag+ (0.3-3.0 mmol/l) and 5.0 g/l Na-Alg (pH=7–10) within 1–5 minutes. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles have a face-centered cubic crystal structure. Zeta potential of plasma-chemically obtained colloidal solutions at various concentrations of Ag+ ions and stabilizing agent varies from −32.8 to −39.3 mV, indicating the moderate stability of synthesized nanoparticles.

The inhibition effect of the grape pomace extract during the early stage of steel corrosion under adsorbed thin electrolyte layers was investigated. The present study was carried out to identify the components present in the 2-propanol grape pomace extract by GC-MS analysis. Gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization, scanning electron microscopy, and FTIR techniques were used to study the corrosion inhibitive. Polarization measurements have indicated that these green inhibitors acted through mixed type inhibition. SEM studies have evidenced the formation of a protective film over metal surface while FTIR supported by molecular modelling has proved that this shielding effect was caused by aldehydes particularly 2-phenylacetaldehyde and 3,7-dimethylocta-2,6-dienal.

In this study, the optimum parameters of membrane desalinization of model solutions were determined and the required efficiency was achieved. Methods for stabilizing treatment of water before barometric desalination were developed to improve the efficiency of membranes. Methods of reagent processing of concentrates after barometric water were proposed to create a low-waste technologies for demineralization of water. It was shown that the precipitate can be used as an additive for cements and a sulfate activator for slag-portland cement.

Corrosion inhibitors are the only most widely applied method for corrosion protection of metallic materials and are of particular importance in industry. Nowadays, the synthesis of corrosion inhibitors using traditional multistep reactions is highly restricted because of the increasing demands of "green chemistry". Plant materials and biomass wastes are ideal green candidatures to replace traditional toxic corrosion inhibitors. Literature survey reveals that different extracts of the plant and agro-food wastes contain naturally phytochemical compounds which have antioxidant properties have been effectively employing as sustainable inhibitors for the corrosion of different metals and alloys. Nevertheless, despite the numerous research papers, the reviews in which the correlation between the antioxidant/free radical scavenging activity of the extracts and their inhibition action is explained are not represented in the literature. This paper provides a brief overview of current knowledge in what kind of methods are used to estimate the antioxidant content, which classes of compounds provide higher antiradical activity and poses questions that we need to answer in order to use parameter of the antioxidant activity as a predictive index for performance evaluation of the plants/biomass wastes extracts as corrosion inhibitors. The conclusion is that no single mechanism of antioxidant actions and anticorrosive protection is operative in plant/wastes extracts. The high inhibitory efficiency is predicated on a number of complementary processes working holistically. By developing the theoretical basis and mechanism of action between the anticorrosive and antioxidant properties of plant extracts, it is possible to create predictive tools for selecting plant extract and further obtaining anti-corrosion protection based on it.