Sonophotocatalytic degradation of trypan blue and vesuvine dyes in the presence of blue light active photocatalyst of Ag3PO4/Bi2S3-HKUST-1-MOF: Central composite optimization and synergistic effect study

• Sonophotocatalytic degradation of TB and VS at 25 min of irradiation and sonication time.
• Sonochemical assisted solvothermal synthesis of Ag3PO4/Bi2S3-HKUST-1-MOF.
• Synergistic index (2.23) indicated that combined system has a positive effect on degradation efficiency.
• Combined of ultrasound irradiation and photocatalysis have higher efficiency compared with sum of the individual processes.

An efficient simultaneous sonophotocatalytic degradation of trypan blue (TB) and vesuvine (VS) using Ag3PO4/Bi2S3-HKUST-1-MOF as a novel visible light active photocatalyst was carried out successfully in a continuous flow-loop reactor equipped to blue LED light. Ag3PO4/Bi2S3-HKUST-1-MOF with activation ability under blue light illumination was synthesized and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), photoluminescence (PL) and diffuse reflectance spectra (DRS). The effect of operational parameters such as the initial TB and VS concentration (5–45 mg/L), flow rate (30–110 mL/min), irradiation and sonication time (10–30 min), pH (3–11) and photocatalyst dosage (0.15–0.35 g/L) has been investigated and optimized using central composite design (CCD) combined with desirability function (DF). Maximum sonophotodegradation percentage (98.44% and 99.36% for TB and VS, respectively) was found at optimum condition set as: 25 mg/L of each dye, 70 mL/min of solution flow rate, 25 min of irradiation and sonication time, pH 6 and 0.25 g/L of photocatalyst dosage. At optimum conditions, synergistic index value was obtained 2.53 that indicated the hybrid systems including ultrasound irradiation and photocatalysis have higher efficiency compared with sum of the individual processes.