Lignin-based N-doped high specific surface area graded porous carbon by premixed precursors: For the adsorption of gaseous benzene and NO

The present investigation involved the preparation of N-doped high-specific surface porous activated carbon from lignin through hydrothermal carbonization, polymer premixing, and KOH activation. We looked at how the characteristics of lignin-based activated carbon were affected by the addition of polypyrrole and the alkali ratio. The addition of polymer polypyrrole as an N dopant during the activation process with KOH resulted in the N-doped biomass-based activated carbon with a greater pore size range, specific surface area, and pore volume, while also further encouraging the pore creation. Under the optimal preparation conditions, specifically hydrothermal treatment at 473 K and activation at 1073 K for 1 h, with a mass ratio of activator to carbon precursor of 4:1, the resulting activated carbon exhibited the highest BET surface area of 3415 m 2 /g and a total pore volume of 2.81 cm 3 /g. The various characteristics of activated carbon are examined using N 2 adsorption/desorption, scanning electron microscopy (SEM), elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Comparing this sample to other adsorbents, it was found that the material had a greater capacity for adsorbing gaseous benzene and NO. In static adsorption tests, the saturated adsorption of gaseous benzene reached 3338.75 and 2297.69 mg/g at 273 and 298 K, respectively, while the adsorption of NO reached 560.76 and 226.99 mg/g. Adsorption isotherms were used to analyze the experimental results, which were then fitted, examined, and assessed to look into the adsorption mechanism. The outcomes demonstrated the good adsorption performance of this sample as well as its promising and useful application potential in the removal of gaseous benzene and NO. Graphical