Photocatalytic degradation of oxytetracycline using ZnO catalyst

Abstract

In the present study, the degradation of oxytetracycline (OTC) under ultraviolet (UV) light in the presence of ZnO catalyst was investigated, and optimum parameters for degradation efficiency were determined. Different pH values, ZnO dosages, reaction times, OTC concentrations, and UV lights were used in this study. The optimum conditions found were as follows: pH 4, ZnO 1 g L−1, reaction time 25 min, and OTC concentration 10 mg L−1. Degradation efficiency was 42.1%, 76%, 70.7%, and 61.7% for ZnO and photocatalytic (for UV‐A, UV‐B, and UV‐C) degradation at optimal conditions, respectively. The resulting products after the photocatalytic oxidation of OTC were determined in the study. To identify the toxicity of degradation products and OTC, the lowest LC 50 (50% lethal concentration) and EC 50 (50% effective concentration) values were found. The resulting ethanamine, 2‐(2,6‐dimethylphenoxy)‐N‐methyl‐ by‐products were observed to be more toxic than OTC. Furthermore, it was seen that isopropoxy carbamic acid, ethyl ester by‐products were formed, whose presence is environmentally risky for aquatic environments due to their low EC50 values.

Synthesis of corn straw based carbon doped Nb 2 O 5 as photocatalysts for Rhodamine B degradation under visible light illumination

“…It has advantages of being non-toxic, highly active, inexpensive, resistant to acid and alkali corrosion, and strong oxidant, making it the most promising photocatalyst for application. In subsequent scienti c research, researchers have discovered that other materials also exhibit excellent photocatalytic performance, such as CdS [1,2], ZnO [3][4][5], WO 3[6, 7] , C 3 N 4[8, 9] , etc. However, there are still many shortcomings for photocatalysts at present, such as the high recombination rate of photogenerated electron-hole pairs, unfavorable band edges, and unclear reaction mechanism.…”