Carbon nitride exfoliation for photocatalysis and photocatalytic ozonation over emerging contaminants abatement

The production of graphitic carbon nitride was studied with the addition of a following exfoliation step using ultrasounds, at different times. The treatment produced catalysts with much higher surface areas, from 2.18 m2 g  1 with no treatment to 28.34 m2 g  1 after 36 h of exfoliation. During exfoliation, melem was also produced, and may further enhance the photoluminescence and photocatalytic properties. The photocatalytic reaction also indicated the improved performance of exfoliated g-C3N4 towards the degradation of a mixture of parabens, enhancing their removal from 20% to up to 65% in 2 h under UVA radiation. The combination of ozone and g-C3N4 photocatalysis was able to completely remove the parabens in under 8 min and with a 20% lower con-sumption of ozone compared to photolytic ozonation. The main reactive species were identified, and the by-products formed during parabens degradation were detected. The efficiency of the combined system was also attested by using a mixture of parabens and other common drugs, maintaining its better performance.