Design of double Z-scheme Ag-Ag 3 O 4 /CuO-CuFe 2 O 4 magnetic nanophotocatalyst via starch-templated microwave-combustion hybrid precipitation method and modified with corona-plasma: Remediation of dye contaminants

Herein, the novel double Z-scheme Ag-Ag O /CuO-CuFe O magnetic nanophotocatalyst with nanosphere-on-nanosheet-like morphology was synthesized via the corona-plasma-assisted starch-templated microwave-combustion-precipitation method to remove the dye pollutants. The CuO-CuFe O meso/macroporous nanophotocatalyst was synthesized using a one-pot-stage combustion-microwave process with/without starch as a hard-template. Subsequently, surface modification was carried out by DC corona-plasma discharge technology at various voltages, namely 500, 1000 and 1500 V. Then, the Ag O photocatalyst was deposited on the CuO-CuFe O fabricated with starch-hard-template and treated with 1000 V corona-plasma (denoted as: Ag-Ag O /CuO-CuFe O (Starch) 1000 P). The properties of the synthesized nanophotocatalysts were analyzed using various techniques, including X-ray diffraction (XRD), Diffuse reflectance spectroscopy (DRS), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller and Barrett-Joyner-Halenda (BET-BJH), Vibrating Sample Manetometer (VSM), and Photoluminescence (PL). The XRD analysis corroborated the presence of CuO, CuFe O and Ag O in the structure of all samples. The BET-BJH analysis indicates that the specific surface area of the Ag-Ag O /CuO-CuFe O (Starch) 1000 P nanophotocatalyst as the best sample is 2 m /g, higher than other samples. Additionally, the DRS analysis revealed that the band gap of the Ag-Ag O /CuO-CuFe O (Starch) 1000 P nanophotocatalyst is about 1.68 eV with the surface plasmon resonance. The performance of the ternary heterostructured Ag-Ag O /CuO-CuFe O (Starch) 1000 P nanophotocatalyst was 96.2% and 89.1% in the degradation of the crystal violet (10 mg/L) and acid orange 7 (10 mg/L), respectively, proving its outstanding degradation capacity.