Waste biomass-derived carbon modified porous graphite carbon nitride heterojunction for efficient photodegradation of oxytetracycline in seawater

A metal - free photocatalyst was developed and synthesized through a single - step thermal treatment process involving banana peel (BP) and urea. The close interfacial connection between biomass-derived carbon (BC) and porous graphite carbon nitride (pg - C3N4) resulted in an increased specific surface area, expanded photoresponse range, effective migration of photo-induced electrons, and enhanced stability. The reaction rate constant of pg-C3N4/BC for degradation oxytetracycline (OTC) in artificial seawater was 9.4 times higher than that of pristine pg-C3N4 after 70 min of visible -light illumination, and pg-C3N4/BC also performed better photocatalytic degradation on OTC in the continuous flow reaction process owing to facilitated photogenerated charge separation and transfer. Additionally, a potential photocatalytic mechanism was proposed to explain the enhanced performance of pg-C3N4/BC composites.