Nanocomposites and nanomaterials

Structural and adsorption properties of carbon-inorganic sorbents filled with Al2O3 
Galaburda M.V.1, Bogatyrov V. M.1, Tomaszewski W.2, Charmas B.3, Mischanchuk A.V.1, Zybert M.2, Gun’ko V. M.1 
1 Chuiko Institute of Surface Chemistry, 17 General Naumov Str., Kyiv 03164, Ukraine. E-mail: mariia.galaburda@gmail.com 
2 Warsaw University of Technology, 00-664 Warsaw, Poland
3Maria Curie-Skłodowska University, 20‑031 Lublin, Poland

The main aim of the work is to create porous nanostructured hybrid carbon- inorganic sorbents and to investigate the structural and adsorption properties.
The composites were prepared by dissolving of resorcinol in formalin with addition of an estimated amount of suspension of fumed Al2O3 under stirring. The weight ratio of resorcinol to formalin (37% aqueous solution) was 1:1.5 for all samples. After the polymerization in hermetically closed containers placed into a thermostatic oven (85 °C, 2.5 h), all samples were dried (85 °C for 18 h) and pyrolyzed in quartz cells of a reactor in an argon flow at 800 °C. Carbonized composites were labeled as RFC-1, RFC-2, and RFC-3.
The morphological, textural, and structural characteristics were investigated using Raman spectroscopy, TG/DTA, nitrogen adsorption-desorption, and SEM methods. The efficiency of the composites for adsorption of explosives was studied using solid phase extraction (SPE) method.
The composites are microporous at SBET = 360-390 m2/g. The Vmicro value changes as RFC-1 > RFC-2 > RFC-3. The SPE results indicated that the highest recovery rates for nitramines and nitric acid esters were for RFC-3 composite, but for nitroaromatic compounds for RFC-1. The highest desorption rates Rdes for nitramines were for RFC-2 and RFC-3, whereas for nitric acid esters and nitroaromatics for RFC-1. These results are is primarily associated with the structural characteristics of the composites. Thus, obtained results are important for the development of carbon adsorbents useful to solve the problems of ecology and environmental protection.
Acknowledgment: the authors are grateful to the Ministry of Education and Science of Ukraine for the financial support of the Ukrainian-Polish Project 2018-2019.