Floatable graphitic carbon nitride/alginate beads for the photodegradation of organic pollutants under solar light irradiation

Graphitic carbon nitride, both as powder and alginate floating beads, was synthesized by an easy and cheap approach using two different precursors (melamine and urea) and properly characterized by several techniques. The effect of the type of precursor on the photoactive properties of the final materials was investigated. Their activity towards the photodegradation of different pollutants (dyes, drugs, and herbicides) both in ultrapure water and simulated drinking water under solar light irradiation was investigated, reaching extraordinarily high photodegradation results (99% for diclofenac and rhodamine B and 90% for isoproturon) compared to the literature. The floating photocatalysts showed good stability during recycling maintaining high performances after 5-time usage without post-treatment. Finally, liquid chromatography equipped with mass spectrometry (UPLC/MS) was used to identify the main by-products formed during the photodegradation tests, and a plausible transformation pathway has been proposed.