Hpl n

Photodegradation of the dyes MB (1 mg/dm³) and RB (1 mg/dm³) under UV radiation was performed in a photochemical cell made of double-walled Pyrex glass in the presence of NH₄BETA, NH₄ZSM-5, and the NaY zeolite. Into the cell, 20 cm³ of the aqueous solution of dye and 0.1 g of zeolite were weighed (exact weight ±10⁻⁴ g), followed by sonification in an ultrasonic bath for 15 min, to achieve a uniform size of the catalyst particles. The photochemical cell was placed on a magnetic stirrer, and the suspension was continuously mixed during the irradiation with a constant oxygen flow. Photodegradation was performed at 283 K and 293 K for 180 min and a high-pressure mercury lamp with a suitable concave mirror was used as a source of UV radiation (Philips, HPL-N, 125 W, with emission bands in the area of UVA radiation at 304, 314, 335 and 366 nm, with an emission maximum at 366 nm).

The photocatalytic potential of the CuO and Ag–CuO were investigated by degradation of methylene blue (MB). Experimentally, solutions of MB with different concentrations were prepared. The specific amount of the synthesized photocatalyst with different Ag doping, was added and stirred in the batch-type reactor under UV visible light illumination till the equilibrium. A bulb ((λ ≥ 420 nm, HPL-N, 125 W, Philips, China) was used to supply visible light irradiation. 5 mL of the mixture was taken out and centrifuged. It was filtered and the dye remaining concentration in the filtrate was determined by checking the absorbance spectrophotometrically. MB has an absorbance band in the visible region at 665 nm. The blue shift in the peak with time confirm the degradation and removal of MB by the photocatalyst. The effect of various parameters such as Ag doping, pH, catalyst amount, contact time, and dye initial concentration were studied to optimize the experimental condition for maximum removal. The percent degradation of MB was calculated by Eq. (2). $$\%Removal=\frac{C_o-C_e}{C_o}\times 100$$ where (C_o) is the initial while (C_e) the is final concentration of the analyte.