Rapid, simple and sustainable preparation of N-rich activated carbons with high performance for gas adsorption, via microwave heating

Rising the activity of activated carbons by surface modification has attracted considerable research attention in the fields of gas adsorption and energy storage. However, conventional functionalization of activated carbons typically requires high cost and long-term heating process. In this work, we report a simple and feasible strategy to prepare N-rich activated carbons with well-developed porosities through microwave heating. Through microwave heating, N-rich (up to 9.35 at.%) activated carbons with high porosities can be prepared within 20 min, reducing preparation time and energy consumption by 77.0% and 99.4%. Under microwave irradiation, the interaction between melamine and carbon precursors is promoted to generate an amount of defects, resulting in the introduction of N species and reducing the consumption of nitrogenous reagents (50%). Moreover, due to the enhanced van der Waals interactions between the nitrogenous carbon surface and molecules, the prepared N-rich activated carbons present excellent increase in breakthrough adsorption capacity of toluene (up to 26.0 %) and CO₂ uptake (9.8 %) with similar pore structure. In summary, this study provides a facile, efficient, and universal strategy for surface modification of activated carbons toward a range of applications.