Graphitic carbon nitride embedded in hot-melt adhesive polyester and hydrophilic cellulose blend fibers for the efficient elimination of antibiotics under solar irradiation

Abstract For a supported catalyst, the interface properties of the carrier material influence the contact efficiency between the catalysts and the target substrates, which has a significant effect on the catalytic activity. As a carrier material, low melting sheath-core composite polyester fiber (LMPET) can be used to immobilize powder catalysts for realizing recyclability. However, due to the hydrophobic interface of LMPET, the contact between photocatalysts and the substrates is insufficient in aqueous solution. In this study, the surface properties of LMPET were changed from hydrophobic to hydrophilic by blending viscose fiber with a 20% proportion. Graphitic carbon nitride (g-C3N4) was then embedded to the blend fiber by a hot-melt adhesive method. The obtained composite was labeled as g-C3N4@LMP/V20. g-C3N4 achieved sufficient contact with organic pollutants through the water conduction of the viscose fiber. Consequently, compared with g-C3N4 being supported on LMPET, g-C3N4@LMP/V20 exhibits a higher activity for the photocatalytic degradation of tetracycline (TC) hydrochloride by increasing the diffusion and permeability between the interfaces under solar irradiation. Additionally, a possible pathway and mechanism for the degradation of TC was proposed. Superoxide radicals were recognized as the dominant active species in the photocatalytic system. In this study, we offer new insight into changing the interface properties of the carrier material to improve the catalytic performance of the supported catalyst.