Nitrogen Doped Carbon Nanospheres: Preparation, Characterization And Its Application In The Treatment Of Organic Wastewater

Carbon materials are of great interest for their important applications in manyfields such as catalysis, hydrogen storage, adsorption, fuel cell. The introduction ofnitrogen or other elements into carbon materials can tune their structure, surfacechemical properties and improved electronic conductivity, and may considerablyenlarge its potential applications. So far, a variety of methods have been developed forthe preparation of nitrogen-containing carbon materials. However, some drawbacks,like high cost, complicated procedures, and environmental pollution, are commonlypresent in the developed methods. Currently, it is a significant subject to developmore efficient methods for preparing novel nitrogen-containing carbon materials withspecial morphology and physico-chemical properties.In the present work, a series of nitrogen doped carbon nanospheres (NCS) wereprepared by hydrothermal synthesis methods with phenol (or catechol) and six methyltetramine (HMTA) as the carbon and nitrogen sources. The morphology, structure andsurface properties of these materials were characterized by means of X-rayphotoelectron (XPS), X-ray powder diffraction (XRD), N2adsorption-desoption,transmission electron microscopy (TEM), thermogravimetry (TG) and elementalanalysis. NCS with uniform spherical morphology (particle sizes are in the range of50-100nm) could be obtained by controlling the hydrothermal synthesis conditionswhen using phenol (or catechol) and HMTAas carbon and nitrogen sources. Materialswith irregular morphology were prepared when other carbon source were used.Changing of the preparation parameters, such as synthesis temperatures, reactantconcentrations, and calcination temperatures, could bring significant effects on theparticle size and nitrogen content of the NCS materials. Moreover, the adsorptionproperties of these NCS materials were investigated for the adsorption of organic dyeof methyl orange in aqueous solution (as mimic wastewater). It was found that all theNCS materials has the capability for the adsorption of methyl orange, and their adsorption capacity changed considerably with the change of nitrogen content in theNCS materials.