Effect of surface modification by nitrogen-containing chemicals on morphology and surface characteristics of N-doped pine bark biochars. Issue 2 (April 2021)

• Record Type: Journal Article
• Authors: Kasera, Nitesh; Hall, Steven; Kolar, Praveen
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 2(2021)
• Publication Date: 2021-04
• Subjects: Biochars -- Nitrogen doping -- Adsorbents -- Waste management -- Melamine; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105161
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: In this study, pine bark-derived biochar was modified with melamine, urea, ammonium chloride, and ammonium nitrate to synthesize nitrogen-doped biochars. The effect of chemical modification on the extent of N-doping and surface properties were investigated. The elemental analysis suggested that melamine modified biochar samples had 4.75% nitrogen, higher than nitrogen in other modified biochars. The surface morphology and surface profile were studied with scanning electron microscopy and confocal laser scanning microscopy. X-ray photoelectron spectra showed that N-doped samples' surface nitrogen content increased to 8.3%, 3.9%, 2.3%, and 2.9% for melamine, ammonium chloride, ammonium nitrate, and urea, respectively. X-ray photoelectron spectroscopy results also revealed that among the nitrogen fractions in the N-doped biochars, melamine modified biochar has the highest percentage of pyrrolic and pyridinic nitrogen (35.2% and 36.8%, respectively) compared to others. Urea modified biochar had the highest percentage of graphitic nitrogen (26.6%). Our results suggest that application-specific nitrogen-enriched biochar can be prepared by understanding how different nitrogen precursors interact with carbon surfaces. Graphical Abstract: ga1 Highlights: Nitrogen-doped biochars have applications in environmental and energy storage. Melamine, urea, ammonium chloride, and ammonium nitrate were used as precursors for nitrogen doping of biochars. Under identical preparation conditions, melamine-doped biochar had the highest nitrogen content. Melamine-doped biochar exhibited the highest percentage of pyrrolic-N and pyridinic-N. Urea-doped biochar contained the highest percentage of graphitic-N.