Green agents for synthesis of silver nanoparticles through multi-round recycling of waste as an alternative to chemical methods: synthesis and characterizations

Green nanoparticle (NP) synthesis is a novel area of nanotechnology that succeeds in terms of biocompatibility, scalability, cost-effectiveness, and environmental friendliness. Due to the widespread of metal nanoparticles in industrial scale applications, green and efficient process that are required free toxic solvent is being emphasized. Plants have lately been used to produce metal nanoparticles as an alternative approach that apply extracts made from as reducing and capping agent. Due to their excellent properties, silver nanoparticles have been widely used for several applications, including as antibacterial agents, in industrial, household, and healthcarerelated products, in consumer products, medical device coatings, optical sensors, and cosmetics. Regarding this, the purpose of our research firstly was to find out whether the green martials Turkish coffee (TC) and Virginia Creeper (VC) extracted and used for synthesis of silver nanoparticles (Ag NPs) could be recycled for further NP synthesis. Another objective was to compare Ag NPs morphology synthesized by biological reagent to chemical reagents as sodium borohydride (NaBH4) as reductant, and sodium citrate and Polyvinyl-Pyrrolidone (PVP) 55k as the stabilizing agents by conventional method. The characteristics of the Ag NPs was confirmed by transmission electron microscopy (TEM), U.V spectroscopy and dynamic light scattering (DLS) measurements

Systematic screening of gas diffusion layers for high performance CO2 electrolysis

Certain industrially relevant performance metrics of CO 2 electrolyzers have already been approached in recent years. The energy efficiency of CO 2 electrolyzers, however, is yet to be improved, and the reasons behind performance fading must be uncovered. The performance of the electrolyzer cells is strongly affected by their components, among which the gas diffusion electrode is one of the most critical elements. To understand which parameters of the gas diffusion layers (GDLs) affect the cell performance the most, we compared commercially available GDLs in the electrochemical reduction of CO 2 to CO, under identical, fully controlled experimental conditions. By systematically screening the most frequently used GDLs and their counterparts differing in only one parameter, we tested the influence of the microporous layer, the polytetrafluoroethylene content, the thickness, and the orientation of the carbon fibers of the GDLs. The electrochemical results were correlated to different physical/chemical parameters of the GDLs, such as their hydrophobicity and surface cracking

Quantitative 3D orientation analysis of particles and voids to differentiate hand-built pottery forming techniques using X-ray microtomography and neutron tomography

This article describes the quantitative analysis of the 3D orientation of objects (i.e. particles and voids) within pottery fabrics to differentiate two categories of pottery hand-building primary forming techniques, specifically percussion-building and coil-building, comparing the use of two independent non-destructive imaging modalities, X-ray microtomography (µ-CT) and neutron tomography (NT). For this purpose, series of experimental organic-tempered vessels and coil sections were analysed. For both imaging modalities, two separate systems were employed for quantitatively describing both the orientation of individual objects, as well as the collective preferential alignment of objects within samples, utilising respectively polar and azimuth angles within a spherical coordinate system, and projected sizes within a positive Cartesian coordinate system. While the former provided full descriptions of the orientations of objects within 3D space, the latter, through a ratio dubbed here the ‘Orientation Index’ (OI), gave a simple numerical value with which the investigated samples were differentiated according to forming technique. Both imaging modalities were able to differentiate between coil-built and percussion-built vessels with a high degree of confidence, with the strength of these findings additionally demonstrated through extensive statistical modelling using Monte Carlo simulations. Despite differences in resolution and differences in the attenuation of X-rays and neutrons, µ-CT and NT were shown to provide comparable results. The findings presented here broadly agree with earlier studies; however, the quantitative and three-dimensional nature of the results enables more subtle features to be identified, while additionally, in principle, the non-destructive nature of both imaging techniques facilitates such structural analysis without recourse to invasive sampling

Methanol oxidation catalyst by atomic layer deposition

Direct liquid fuel cells (DMFCs) are very appealing alternatives for fighting climate change, particularly in the field of personal mobility solutions. However, DMFCs also have some serious competitive disadvantages, like the high cost of the noble metal catalysts, the difficulties of the catalyst application, and the poisoning of the catalyst due to carbon monoxide formation. Here we demonstrate that depositing platinum on TiO2 by atomic layer deposition (ALD) is an easy, reproducible method for the synthesis of TiO2-supported platinum catalyst for methanol oxidation with excelent anti CO poisoning properties