Nitrogenization of Biomass-Derived Porous Carbon Microtubes Promotes Capacitive Deionization Performance

Abstract Nitrogenization of porous carbon provides an effective methodology to promote capacitive deionization (CDI) performance. Exploring a new class of nitrogen-doped porous carbons from waste biomass over commercially available activated carbons is of significant interest in CDI. In this contribution, we present the preparation of nitrogen-doped porous carbon microtubes (N-CMTs) by pyrolyzing willow catkins, a naturally abundant biomass with urea as the nitrogen source. Due to the naturally occurring hollow microtube structure and the high nitrogen content, the as-prepared N-CMTs show an enhanced desalination performance compared to undoped samples. A high deionization capacity of 16.78 mg g−1 predicted by Langmuir isotherm and a stable cycling performance over ten cycles are observed. The result advocates the importance and significance of naturally developed architectures and chemistry for practical CDI application.