A dandelion-like NiCo2O4 microsphere with superior catalytic activity as the mediator of persulfate activation for high-efficiency degradation of emerging contaminants. Issue 1 (February 2022) - Cong, Yanqing
Abstract: Nowadays efficient treatment of emerging organic contaminants is still a complex task with a big challenge. Herein, a novel dandelion-like NiCo2 O4 microsphere was synthesized by a simple step-by-step self-assembly strategy, and obtained NiCo2 O4 was then as an efficient heterogeneous catalyst to activate PS for rapid degradation of emerging organic pollutants. Importantly, as-prepared NiCo2 O4 -300 microsphere not only exhibited great catalytic activity, but also possessed excellent performance stability and structural stability. More significantly, developed NiCo2 O4 -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 H2 O, CO2 and other byproducts, and wherein degradation byproducts were low toxicity or no toxicity. During the process of PS activation over NiCo2 O4 -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 SO4 − and OH were main active species in the reaction system. Even in actual water samples, proposed NiCo2 O4 -300/PS oxidation system still showed great performance for removing pollutants. In short, current work would provide valuable references for further research. Graphical abstract: ga1 Highlights: Prepared NiCo2 O4 microsphere had good performance stability and structural stability. Both redox couples of Co 3+ /Co 2+ and Ni 3+ /Ni 2+ provided richer redox reactions. Proposed NiCo2 O4 /PS oxidation system had good removal performance for many pollutants. Proposed NiCo2 O4 /PS oxidation system displayed great practical application ability. Degradation byproducts of tetracycline were low toxicity or no toxicity.