CuFe2O4@GO nanocomposite as an effective and recoverable catalyst of peroxymonosulfate activation for degradation of aqueous dye pollutants

Recently, heterogeneous activation of peroxymonosulfate (PMS) to oxidatively degrade organic pollutants has been a hotspot. In the present work, copper ferrite-graphite oxide hybrid (CuFe2O4@GO) was prepared and used as catalyst to activate PMS for degradation of methylene blue (MB) in aqueous solution. A high degradation efficiency (93.3%) was achieved at the experimental conditions of 20 mg/L MB, 200 mg/L CuFe2O4@GO, 0.8 mmol/L PMS, and 25 °C temperature. Moreover, CuFe2O4@GO showed an excellent reusability and stability. The effects of various operational parameters including pollutant type, solution pH, catalyst dosage, PMS dosage, pollutant concentration, temperature, natural organic matter (NOM), and inorganic anions on the catalytic degradation process were comprehensively investigated and elucidated. The further mechanistic study revealed the Cu(II)/Cu(I) redox couple on CuFe2O4@GO played the dominant role in PMS activation, where both hydroxyl and sulfate radicals were generated and proceeded the degradation of pollutants. In general, CuFe2O4@GO is a promising heterocatalyst for PMS-based advanced oxidation processes (AOPs) in wastewater treatment.