Nitrogen-Functionalized Hydrothermal Carbon Materials by Using Urotropine as the Nitrogen Precursor

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Hydrothermal carbonization (HTC) is a thermochemical process for converting biomass into carbon materials.
• Nitrogen-doped carbons are of interest for various applications due to their unique properties.
• Controlling nitrogen content and structure in HTC materials remains a challenge.

Purpose of the Study:

• To synthesize nitrogen-containing hydrothermal carbon (N-HTC) materials with controlled nitrogen content.
• To comprehensively investigate the structural and chemical properties of N-HTC materials.
• To elucidate the reaction mechanisms and pathways involved in N-HTC formation.

Main Methods:

• Hydrothermal synthesis using glucose and urotropine as precursors.
• Varying the molar ratio of glucose to urotropine to control nitrogen content.
• Utilizing a suite of analytical techniques including FTIR, thermogravimetric MS, and solid-state NMR.
• Performing electronic structure calculations to complement experimental data.

Main Results:

• Spherical N-HTC materials were successfully synthesized with nitrogen content up to 19 wt%.
• The pH significantly influences the reaction pathways during N-HTC formation.
• FTIR, TGA-MS, and NMR spectroscopy identified polyfuran and polypyrrole-like structures.
• Electronic structure calculations provided insights into reaction mechanisms and structural details.

Conclusions:

• The study demonstrates a method for controlled synthesis of N-HTC materials with high nitrogen content.
• A comprehensive understanding of N-HTC formation mechanisms and structural characteristics was achieved.
• The findings contribute to the development of advanced nitrogen-doped carbon materials for diverse applications.