A dandelion-like NiCo2O4 microsphere with superior catalytic activity as the mediator of persulfate activation for high-efficiency degradation of emerging contaminants

Nowadays efficient treatment of emerging organic contaminants is still a complex task with a big challenge. Herein, a novel dandelion-like NiCo 2 O 4 microsphere was synthesized by a simple step-by-step self-assembly strategy, and obtained NiCo 2 O 4 was then as an efficient heterogeneous catalyst to activate PS for rapid degradation of emerging organic pollutants . Importantly, as-prepared NiCo 2 O 4 -300 microsphere not only exhibited great catalytic activity , but also possessed excellent performance stability and structural stability. More significantly, developed NiCo 2 O 4 -300/PS oxidation system displayed strong degradation ability toward typical contaminants, including TC , IBP, SMX, BPA , DFC as well as OFX. TOC analyses revealed that these organic pollutants could eventually be degraded into H 2 O, CO 2 and other byproducts, and wherein degradation byproducts were low toxicity or no toxicity. During the process of PS activation over NiCo 2 O 4 -300, the redox couples of Co 3+ /Co 2+ and Ni 3+ /Ni 2+ provided major catalytic sites, and the redox couples of Ni 3+ /Ni 2+ played a bigger role. Furthermore, it was also found that both SO 4 −• and •OH were main active species in the reaction system. Even in actual water samples, proposed NiCo 2 O 4 -300/PS oxidation system still showed great performance for removing pollutants. In short, current work would provide valuable references for further research.