Photodegradation of emerging contaminant tetracycline using a zinc titanate nanocellulose composite as an efficient photocatalyst

There is an urgent need to mitigate emerging contaminants, viz. pharmaceuticals, etc. In this work, efforts have been made to develop zinc titanate (ZnTiO3)-based efficient photocatalysts to photodegrade tetracycline. Zinc titanates (ZnTiO3) were synthesized by a simple sol-gel method. ZnTiO3 was subjected to different calcination temperatures. In addition, a composite of carbon dot-doped zinc titanate and zinc titanate-cotton nanocellulose was also synthesized. The prepared samples were then characterized using UV-Vis spectroscopy, FTIR spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), Raman spectrometry etc. The calcinated ZnTiO3 at temperatures of 600 degrees C, 700 degrees C, 800 degrees C and 900 degrees C, carbon dot-doped calcinated ZnTiO3 and ZnTiO3-nanocellulose composites were examined for their photocatalytic activity in the degradation of tetracycline hydrochloride under light illumination. The photocatalytic studies demonstrated that ZnTiO3 calcinated at 600 degrees C, carbon dot-doped ZnTiO3 calcinated at 600 degrees C and the ZnTiO3-nanocellulose composite show the highest photocatalytic activity of degradation of tetracycline hydrochloride under light illumination with degradation rates of 98.27%, 99.14%, and 99.81%, respectively. A pH-dependence study (pH 2-11) reveals that the photodegradation process does not depend on pH and the catalytic efficiency is not affected by different pH values. The study also involved investigating the active species that play crucial roles in the degradation process of tetracycline hydrochloride under light illumination. It was observed that holes and superoxide ions play pivotal roles in the degradation of tetracycline hydrochloride. Such studies help in finding solutions for mitigation of emerging contaminants.

Automated summary

This study focuses on the development of efficient photocatalysts based on zinc titanate (ZnTiO3) for the degradation of tetracycline, an emerging contaminant. The synthesized ZnTiO3 samples were characterized using various techniques such as UV-Vis spectroscopy, FTIR spectroscopy, XRD, SEM, and Raman spectrometry. The results showed that ZnTiO3 calcinated at 600 degrees C, carbon dot-doped ZnTiO3 calcinated at 600 degrees C, and the ZnTiO3-nanocellulose composite exhibited the highest photocatalytic activity with degradation rates of 98.27%, 99.14%, and 99.81% respectively. The study also identified the active species involved in the degradation process of tetracycline hydrochloride under light illumination, including holes and superoxide ions. These findings contribute to the development of strategies for mitigating emerging contaminants.