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

) and good retention of capacitance (92% even after 10 000 cycles). This work demonstrated that both solid and liquid HTC fractions from this bio-waste can serve as effective sources to prepare functional carbon materials, making this approach a sustainable zero-waste biomass conversion process.