Graphene oxide (GO) and reduced graphene oxide (rGO) sheets have usually been synthesized through Hummers' method by using highly pure graphite (HPG) as the main starting material. However, HPG can be relatively expensive for mass production of high-quality graphene. In this work, a general method for synthesis of high-quality GO and rGO sheets from various natural and industrial carbonaceous wastes such as vegetation wastes (wood, leaf, bagasse, and fruit wastes), animal wastes (bone and cow dung), a semi-industrial waste (newspaper), and an industrial waste (soot powders produced in exhaust of diesel vehicles) was developed. Based on atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and current-voltage characteristics of the synthesized sheets, the single-and multi-layer properties, chemical state, carbonaceous structure, and electrical properties of the graphene sheets synthesized from various waste materials (with #4-monolayer thicknesses and electrical sheet resistance of $10 5 MU sq À1 for GO and $1 MU sq À1 for rGO sheets) were found to be nearly independent of the starting materials used; moreover, they were comparable to those of the high-quality graphene sheets achieved using HPG. These results provide a possible route for inexpensive mass production of highquality graphene sheets from natural and industrial carbonaceous wastes.

No abstract

In the title compound, C12H10N2O3, the dihedral angle between the benzene ring and the furan ring is 16.12 (13)°. The conformation is stabilized by an intra­molecular O—H⋯N hydrogen bond. Inter­molecular N—H⋯O hydrogen bonds with the keto group as acceptor lead to strands along [001]. The mol­ecule displays a trans configuration with respect to the C=N and N—N bonds.

In this work, a special rhombus-like structure of CdO composed of particles at the nanometre scale was successfully synthesized for the first time. A facile hydrothermal process with a post-reaction calcination was employed to prepare this nanomaterial. Scanning electron microscopy (SEM) images showed that the obtained rhombus-like structure consists of nanoparticles with an average size of 29 nm. The band gap energy of 1.9 eV based on a diffuse reflectance spectroscopy (DRS) showed that the product can be favourable to photoactivity in the visible region of sunlight. The prepared sample was employed to destruct carcinogenic azo dyes, such as Congo Red (CR), Malachite Green (MG) and Crystal Violet (CV). The obtained results showed that the CdO with the special morphology was able to effectively catalyse the degradation of these pollutants. The related decolourization efficiencies were obtained by up to 100% after various lengths of time of light irradiation. It was concluded that the photodegradation of the mentioned organic dyes under visible light irradiation by a CdO rhombus-like nanostructure follows the first-order reaction kinetics. The effect of the initial pH and contact time on the percentage of the decolourization of these organic dyes was also studied.

No abstract