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Graphene oxide (GO) synthesized according to the modified Hummers method was reduced by supercritical isopropyl alcohol (SCI), supercritical acetone (SCA), and supercritical water (SCW). Methods free of toxic reducing agents were developed for the graphene production. The composition, morphology, and structure of synthesized graphene were determined using CHN analysis, XRD, Raman spectroscopy, and scanning electron microscopy. The best results were acquired in the case of GO reduction in SCA and SCI at high parameters. [ABSTRACT FROM AUTHOR]

Three-dimensional opal-matrix nanocomposites containing various bismuth selenides and tellurides with a particle size from 25 to 150 nm have been produced by reducing oxygen-containing compounds with supercritical isopropanol. The bismuth: chalcogen ratio in the reduction products has been shown to correlate with that in the starting mixtures, indicating that targeted synthesis in opal pores can be used to controllably fabricate nanocomposites. [ABSTRACT FROM AUTHOR]

Bi, Te, and Bi2Te3 nanoparticles have been prepared by reducing bismuth salts, telluric acid, and their decomposition products with supercritical isopropanol in opal pores. [ABSTRACT FROM AUTHOR]

We have studied the reactions between supercritical isopropanol and salts of various elements (silver, copper, gold, zinc, iron, nickel, cobalt, manganese, europium, ruthenium, antimony, bismuth, and tellurium) infiltrated into opal photonic crystals. According to transmission electron microscopy data, the diameter of the SiO2 spheres in the opal crystals is 260 nm, and the nanoparticles of the metals and incomplete reduction products range in size from 2 to 80 nm, i.e., are no greater in size than the opal pores. [ABSTRACT FROM AUTHOR]

Bismuth nanoparticles have been produced in pores of opal matrices by reducing bismuth salts and oxide compounds with supercritical isopropanol. According to transmission electron microscopy data, the diameter of the SiO2 spheres in the opal matrices is about 260 nm, and that of the bismuth nanoparticles does not exceed 80 nm. [ABSTRACT FROM AUTHOR]