Process Optimization for the Photodegradation of Methylene Blue Dye Over CuO/AC Catalyst

ABSTRACT

A nanofiber of copper oxide on activated carbon (CuO/AC) was synthesized by mechanochemical process. X‐ray diffractometer (XRD), Fourier‐transform infrared spectroscopy (FTIR), S _BET , scanning electron microscopy (SEM), transmission electron microscopy (TEM), and optical analysis were applied for characterization the catalyst. The results indicated that the BET surface area of CuO/AC is 13 m ²  g ⁻¹ , zeta potential is −52.1 mV, electrical conductivity is 0.377 mS cm ⁻¹ , and energy of bandgap is 1.31 eV. A central composite experimental design technique combined with response surface methodology has been used to study the influence of various operating variables such as catalyst dose (0.5–2.5 g L ⁻¹ ), dye concentration (10–50 ppm), adsorption time (20–100 min), and irradiation time (30–150 min) on the photodegradation % of methylene blue dye in visible light. It was found through the analysis of variance that the quadratic polynomial models suggested provided good correlation of the data obtained, with a high value of the F ‐ratio (coded model—80.53; actual model—103.2) and R ² adjusted >0.95.