Tuning of Carbon Microspheres and Graphene Structures with Hetero Atoms for Organic Dye Degradation and Heavy Metal Remediation - Influence of Fructose as a Precursor

Abstract

In today’s context, there is a tremendous potential for the design of smart nanomaterials of carbon origin for multi-dimensional applications. The role-play of precursor is significant in the design of nanometric carbon materials apart from other experimental parameters. Correlation of the synthetic methodology, the microstructure of the product helps to tune and widen the applications aspect. The present study aimed to tune the simple ketose (reducing monosaccharide) of fructose to functionalize (with O, N, and S atoms) carbon layers, microspheres of carbon, to optimize the experimental conditions, and to establish the mechanism involved in the process. The study further explored the catalytic ability of the carbon samples in the degradation of thiazine and xanthene-based textile dyes and the sensing of heavy metal ions of chromium and copper. A simple hydrothermal process, fructose as a precursor, alkaline pH, and appropriate calcination temperature provided micro and nanostructures of carbon viz. carbon microspheres (CMs), graphene oxide (GO), sulfur doped graphene oxide (S-GO), and nitrogen-doped reduced graphene oxide (N-rGO). In this study a simple mechanism for the conversion process is suggested. Further, the results of the preliminary screening study on the catalytic ability of the sulfur and nitrogen-doped graphene samples in the presence of UV and Visible light upon the degradation of methylene blue (MB), methyl orange (MO), Rhodamine-B (Rh-B) dyes were satisfactory. The adsorbent and the ion exchange capacity of the carbon microspheres were found to be excellent. The results of the study will contribute positively to the treatment and management of industrial wastewater.

Keywords

• hydrothermal method, carbon microspheres, graphene oxide, photocatalyst, organic dyes, heavy metal ions