Rational engineering and fabrication of efficient nanophotocatalysts based on ZnO-SrO-CdS for pharmaceutical pollutants based wastewater degradation

Abstract

Cleaner production processes in conjunction with sustainability is the main requirement for clean and cost-effective industrial process. Moreover, the rapid growth of the world population in conjunction with limited sources of drinking water anticipated water crisis in many countries. Herein, indirect Z-scheme ZnO-3%SrO-2CdS photocatalyst was fabricated for the first time via thermal treatment and well identified by XRD, FT-IR, SEM, EDX and, XPS, meanwhile, the optical properties were evaluated using DRS, PL, and EPR analyses. The photocatalytic activity of noble metal free ZnO-3%SrO-2CdS was investigated in the photodegradation of six antibiotics, namely tetracycline, doxycycline, ofloxacin, amoxicillin, cephalexin, and sulfamethoxazole. Furthermore, kinetic study, pH, initial concentration, dosage, mass ratio, photoreactor type and different water source parameters have been investigated. Results demonstrated a high removal efficiency of tetracycline by ZnO-3%SrO-2CdS of 98.8% within 120 min at pH 7 and dosage 10 mg. This high efficiency could be attributed to SrO channels that facilitate charge migration process and conserve electrons/holes with high redox power for reactive oxygen species production. Besides, the hydroponics study to examine the phytotoxicity of treated tetracycline solution reflected the effectiveness of the treating process since T. foenum-graecum seeds were germinated successfully in the treated tetracycline solution.