Low-cost effective photocatalytic activity under visible light of pitch-based porous carbon nanofiber composites aided by zinc oxide

Abstract

To explore and develop an economical, novel, and effective photocatalyst for the degradation of methylene blue (MB) under visible-light irradiation, polyacrylonitrile (PAN)/pitch-based carbon nanofibers (CNFs) with ZnO (PPZn) are successfully produced by one-step electrospinning of PAN, pitch, and zinc acetate in dimethylformamide (DMF) solution. The charge separation rate, adsorption capacity, and visible-light harvesting effects are all enhanced by the synergistic effect of PAN/pitch-based CNFs and ZnO coupling. The resulting PPZn photocatalysts exhibit excellent removal capacity of 100% of MB within 30 min and a kinetic rate constant of 0.018 min−1 under visible light. PPZn also exhibits a consistent and stable photocatalytic performance by maintaining nearly 100% removal of 15 ppm MB over 8 regeneration cycles. The PP-based CNFs in PPZn act as a charge reservoir to afford fast transport for suppressing the e--h+ recombination and high electrical conductivity induced by the pitch, thereby expanding the visible-light response. The PP(3)Zn composites demonstrate a promising potential as a low-cost photocatalyst material offering excellent photocatalytic efficiency in the visible-light spectrum.