Meso-microporous carbon nanofibers with in-situ embedded Co nanoparticles for catalytic oxidization of azo dyes

Abstract

To meet the current challenges in the treatment of azo dye wastewater by advanced oxidation processes (AOPs), meso-microporous carbon nanofiber with in-situ embedded Co nanoparticles (Co/P-CNF) is developed by electrospinning Co salt/polyvinylpyrrolidone (PVP)/polyacrylonitrile (PAN) solution followed by carbonization process. The use of PVP as pore-forming agent in PAN solution promotes the formation of meso-microporous structure of P-CNF in carbonization phase, achieving micropore surface area of 98 m2 g−1 and mesopore surface area of 214 m2 g−1 by BET analysis. The heterogeneous catalytic performance of synthesized Co/P-CNF is evaluated by the degradation of Acid Red 1 (AR1) with peroxymonosulfate (PMS). Complete removal of AR1 of 50 × 10−6 M is achieved within 6 min by Co/P-CNF and PMS system. The superior catalytic performance of Co/P-CNF is attributed to both the nanofibrous morphology and meso-microporous structure due to using the pore-forming agent (PVP), which endow the uniform distribution of Co nanoparticles, favor the exposure of active sites and promote electron and mass transfer. Co/P-CNF not only possesses excellent magnetic property but also has good stability and recyclability, which is desirable for the practical application of the treatment of azo dye wastewater. Co/P-CNF is validated to activate PMS using Co0/Co2+/Co3+ for generating sulfate radicals, hydroxyl radical and singlet oxygen and then degrade AR1. Therefore, the combination of electrospun nanofibrous structure and the use of pore-forming agents is a promising strategy for the preparation of high-performance carbon nanofiber supported catalysts.