Dielectric barrier discharge low-temperature plasma-assisted directed conversion of sargassum: Syngas and porous...

Dielectric barrier discharge low-temperature plasma (DLTP) is an environmentally friendly material processing technology that generates high-energy species by exciting the reaction gas to facilitate biomass transformation. This study innovatively employs DLTP to process Sargassum (SA) first for high-quality syngas production, and then the residual char for supercapacitors. Gasification results showed that CO₂ plasma produced significantly higher gas yield than N₂ or Ar plasmas. Increasing the discharge voltage enhanced gas production. The addition of K₂CO₃ (which catalyzes active site generation and optimizes the reaction pathway) significantly increased both yield and production rate. For supercapacitor electrodes, DLTP transformed SA residual char into a hierarchically porous carbon material. The modified carbon, prepared at 50 V in CO₂ atmosphere for 20 min, exhibited a high specific surface area of 1012.98 m² g^-1 and excellent chemical stability, with a significantly increased proportion of oxygen-containing functional groups. Its specific capacitance reached 173F g^-1 at 0.5 A g^-1, a 69.6 % enhancement compared to untreated carbon. DLTP achieves dual optimization of biomass syngas and electrode materials, providing a controllable and high-value utilization pathway for biomass resources.