Spongelike porous CuO as an efficient peroxymonosulfate activator for degradation of Acid Orange 7

The morphology and structure of heterogeneous catalysts play crucial roles in peroxymonosulfate (PMS) acti- vation by providing much more available active sites and high chemical stability. In this work, spongelike porous CuO (SP-CuO) was synthesized and used as a PMS activator to degrade Acid Orange 7 (AO7) from aqueous solution. The morphology and property of SP-CuO were characterized using various techniques. The results showed that nanoparticles of SP-CuO with uniform in size were agglomerated together to form a porous spongelike texture. In the catalytic experiments, SP-CuO showed highly effective in heterogeneous activation of PMS compared to commercial CuO and Co3O4. The first -order rate constant of SP-CuO was approximately 3.9 and 4.4 times greater than that of commercial CuO and Co3O4, respectively. The effects of experimental para- meters including PMS dose, AO7 concentration, catalyst dosage, temperature and pH were systematically in- vestigated. The highest degradation rate was achieved at pH 7.0. The activation energy of SP-CuO was obtained as 21.6 kJ mol(-1) . Sulfate radical (SO4 center dot-), mainly generated through heterogeneous reaction, was the dominant reactive species for AO7 degradation. Moreover, SP-CuO remained good activity and stability after being recycled five times, demonstrating its potential environmental application in the treatment of dye wastewater.