Metal-Carbon Composites Based on Lignosulfonates

Abstract

The synthesis of the new nanostructured metal-carbon composites (NMCC) based on lignosulfonates was proposed. Obtaining and studying the properties of NMCC is a crucial task of modern materials chemistry due to the use of the materials based on them in various fields of science and technology as ion-selective electrodes and electrochemical cathodes, supercapacitors, magnetic sensors, information recording and storage devices, heterogeneous catalysts. The synthesis method, which allows the formation of particles of a certain shape and size, which subsequently determine the properties of the composite material (sorption, electrochemical, catalytic, magnetic and optical), acquires decisive importance in the production of the new materials. The research purpose is to study the influence of the synthesis conditions of NMCC based on carbon-containing organic raw materials (lignosulfonates, chitosan and polyethylene polyamine) and embedded metal on the structure and physico-chemical properties of the new materials. The feature of the developed approach is the colloid-chemical synthesis with subsequent carbonization, which allows to obtain a highly dispersed NMCC with the developed micro- and mesoporous structure, specific surface area up to 400 m²/g and a narrow particle size (30–65 nm) distribution. Metal binds to sodium lignosulfonate (LS) at the stage of chelate complex formation, which upon mutual coagulation with chitosan (CT) or polyethylene polyamine (PEPA) forms a water-insoluble compound (polymer metalorganic omplex). The degree of extraction of Co(II) ions from aqueous solutions during the formation of the LS–Co–CТ metal complex is 78.6 % (LS : CТ mass ratio is 1 : 0.25) and the LS–Co–PEPA complex is 56.3 % (LS : PEPA mass ratio is 1 : 0.1). Centrifugation and washing with acetone followed by carbonization allow the metal to be fixed in the structure of the NMCC. The synthesis conditions, including the quantitative ratio of polymer components (LS : CT – 1 : 0.25 and LS : PEPA – 1 : 0.1), the duration of the formation of the chelate complex (1 h) and the metal-organic composite (1 h) and pH (4–6), were analyzed. The morphology of the NMCC was studied by electron microscopy, and the parameters of the porous structure were found by the method of low-temperature nitrogen adsorption. Carbon nanomaterials based on cheap starting polymers and obtained in the mild synthesis conditions are promising for practical use as effective sorbents and catalysts, as well as for environmental protection.
For citation: Brovko O.S., Palamarchuk I.A., Gorshkova N.A., Ivakhnov A.D. Metal-Carbon Composites Based on Lignosulfonates. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 3, pp. 159–168. DOI: 10.37482/0536-1036-2020-3-159-168
Funding: The studies were carried in the course of the state assignment of the N. Laverov Federal Center for Integrated Arctic Research within the framework of the Fundamental Research Program 2018–2020 “Physical and Chemical, Genetic and Morphological Fundamental Principles of Adaptation of Plant Objects in a Changing Climate of High Latitudes” (No. AAAA-A18-118012390231-9) using the equipment of the Core facility center “Arktika” (NArFU) and the Core facility center “Critical Technologies of the Russian Federation in the field of Environmental Safety of the Arctic” (FSIARctic RAS).