Green and sustainable zero-waste conversion of water hyacinth () into superior magnetic carbon composite adsorbents and supercapacitor electrodes.

Troublesome aquatic weed, water hyacinth () was converted into solid and liquid fractions green and energy-saving hydrothermal carbonization (HTC). The solid product, hydrochar, was employed as a precursor to prepare magnetic carbon materials by simple activation and magnetization using KOH and Fe ions, respectively. The obtained magnetic adsorbent possessed good magnetic properties and presented outstanding capacities to adsorb methylene blue (524.