Photocatalytic Degradation of Tetracycline by Z-Scheme Bi2WO6/ZIF-8

To improve the photocatalytic activity of Bi2WO6, ZIF-8 was successfully introduced with the in-situ growth for the first time. The addition of ZIF-8 effectively inhibited the recombination of photogenerated electron-hole pairs with further improved electron utilization efficiency. The superoxide anion, .O-2(-), generated, greatly improved the photocatalytic activity. The performance of Bi2WO6/ZIF-8 in the photodegradation of tetracycline (TC) was studied under different conditions, including the proportions of ZIF-8, the dosage of catalyst, and the concentration of TC. The results indicated that 10 mg of B/Z/5/1 offered the best photocatalytic activity under UV light, achieving 97.8% degradation of TC (20 mg/L) within 80 min. The measured rate constant (k) for TC degradation was almost 3 times that of pure Bi2WO6. The effects of pH, HA, and inorganic anions on the degradation of TC were also studied for the simulated real water. Further, B/Z/5/1 could be reutilized up to five cycles without reduction of the catalysis performance. Therefore, the Bi2WO6/ZIF-8 heterojunction composite material can be utilized as an efficient photocatalyst for remediation of environmental pollution.