SnS2 modified carbonate-intercalated Ni-Zn-Fe trimetallic LDH as a novel photocatalyst for persulfate activation: Influence of operational parameters, co-existing ions and organic compounds

Abstract

Herein, novel SnS2/CO32–@ Ni-Fe-Zn LDH (SCL) QDs were fabricated by growing carbonate-intercalated Ni-Fe-Zn LDH over SnS2 nanoparticles via a facile co-precipitation technique to activate persulphate (PS) under visible light irradiation. Ofloxacin (OFL) was chosen as an emerging organic pollutant to appraise the photocatalytic activity of the SCL + PS system under visible light irradiation. The effect of various process parameters affecting PS activation was assessed, and the mechanism of the degradation of OFL via PS activation is presented. The study of the synergistic effect of SCL for PS activation versus H2O2 activation showed that it is a better PS activator compared to the H2O2 activator. About 93.11 ± 1.46 % of 20 ppm OFL with a catalyst dosage of 0.4 g/L and PS concentration of 6 mM was degraded within 100 min at neutral pH. The effect of inorganic cations, anions, dissolved organic matter, and water matrices was also investigated to examine the applicability of the SCL + PS system under a real wastewater system. Furthermore, the reusability tests suggested that the prepared photocatalyst was highly stable and reusable for up to five consecutive cycles. Moreover, the as-prepared SCL QDs also showed significant degradation of other emerging pollutants with a degradation efficiency of>80 %. The present research highlighted the significance of SCL for PS activation under visible light for the photodegradation of emerging pollutants and wastewater treatment.