Design of double Z-scheme Ag–Ag3O4/CuO–CuFe2O4 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–Ag3O4/CuO–CuFe2O4 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–CuFe2O4 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 Ag3O4 photocatalyst was deposited on the CuO–CuFe2O4 fabricated with starch-hard-template and treated with 1000 V corona-plasma (denoted as: Ag–Ag3O4/CuO–CuFe2O4 (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, CuFe2O4 and Ag3O4 in the structure of all samples. The BET-BJH analysis indicates that the specific surface area of the Ag–Ag3O4/CuO–CuFe2O4 (Starch) 1000 P nanophotocatalyst as the best sample is 2 m2/g, higher than other samples. Additionally, the DRS analysis revealed that the band gap of the Ag–Ag3O4/CuO–CuFe2O4 (Starch) 1000 P nanophotocatalyst is about 1.68 eV with the surface plasmon resonance. The performance of the ternary heterostructured Ag–Ag3O4/CuO–CuFe2O4 (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. •Design of the meso-/macroporous Ag–Ag3O4/CuO–CuFe2O4 magnetic nanophotocatalyst.•Applying plasma-assisted starch-templated microwave-combustion-precipitation techniques.•Nanosphere-on-nanosheet-like architecture with honeycomb-like pores.•Potential effect of starch hard-templating on the phases and morphology.•Confirming the influence of different voltages of DC corona-plasma on properties.