In-situ synthesis of CuS@carbon nanocomposites and application in enhanced photo-fenton degradation of 2,4-DCP

Abstract Novel CuS nanoparticles embedded into carbon nanosheets (CuS@CNs) were prepared in situ by applying wheat straw cellulose/feather protein hydrogel beads as templates and were used to photocatalytically activate H2O2 to degrade 2,4-dichlorphenol (2,4-DCP). The photo-Fenton catalytic properties of the nanocomposite catalysts obtained under different synthetic conditions, including different Cu2+ concentrations, S2− concentrations and calcination temperatures, were evaluated. The results showed that CuS@CNs with 0.1 M Cu2+, 0.1 M S2− at 800 °C presented excellent photo-Fenton degradation performance for 2,4-DCP (25 mg/L) in the presence of H2O2 and could remove 90% of 2,4-DCP in 2.5 h. The water quality parameters (pH, Cl−, HCO3−, H2PO4− and SO42−) exhibited different effects on the photocatalytic degradation process. The catalytic activity of the CuS@CNs used in the cycle could be recovered after thermal regeneration. Radical quenching and electron paramagnetic resonance (EPR) experiments confirmed that ·OH species were main active radicals contributing to the degradation of 2,4-DCP. The photocatalytic mechanism of CuS@CNs was also explored by photoelectrochemical (PEC) measurements and UV–vis diffuse reflectance spectroscopy (DRS). Incorporation of carbon nanosheets could significantly improve the separation of photogenerated charge carriers to stimulate pollutant degradation by CuS. Based on the detected intermediates, the degradation pathway of 2,4-DCP in the CuS@CNs/H2O2 reaction system was also proposed.