Adsorptive removal of cationic dyes from water with polypyrrole-derived porous carbons

초록

Polypyrrole-derived carbons (PpDCs) were obtained via pyrolysis of polypyrrole under various preparationconditions. After characterization, PpDCs were used for the adsorptive purification of water contaminated withorganic dyes. One PpDC (PpDC-800) exhibited the highest adsorption capacity (Qo) for cationic dyes (e.g.,methylene blue and crystal violet) compared to other adsorbents. The adsorption capacity of PpDC-800 formethylene blue and crystal violet was approximately seven times higher than that of activated carbon. Theeffective adsorption of cationic dyes (200 mg/L) over PpDC-800 was also observed in water with very lowconcentrations of methylene blue or crystal violet (1 mg/L), which causes toxicity and affects aesthetics. PpDC-800 showed high selectivity for methylene blue adsorption from an equivalent-weight mixture of anionic methylorange and cationic methylene blue. Plausible adsorption mechanisms of methylene blue removal, such aselectrostatic and π–π interactions, have been suggested. Structural characterization and adsorption mechanismwere confirmed using XRD, N2 adsorption, Raman spectroscopy, SEM, XPS, zeta potential analysis, and othertechniques. The facile regeneration of PpDC-800 was confirmed through successive adsorption/reactivationcycles using FT-IR, N2 adsorption, Raman, and SEM analyses. PpDC-800 is one of the most promising adsorbentsfor the effective and selective removal of cationic dyes from water.

키워드