Synthesis and application of CdS nanorods for LED-based photocatalytic degradation of tetracycline antibiotic

Abstract

With the rapid development of pharmaceutical industrialization, increased consumption of drugs and discharged sewage contains antibiotics that lead to water contamination. For this purpose, removal of antibiotics from aquatic environment is emphasizing the need to produce clean water using easy separable catalysts through photocatalytic water remediation and thus the semiconductor photocatalysts have presently gained fascinating unprecedented research attention. Herein, we present the synthesis of semiconductor CdS nanorods by a facile hydrothermal procedure using ethylene diamine as a coordinating agent. Then, we subsequently studied the photocatalytic activity of CdS nanorods under blue and white LED light irradiation for the degradation of tetracycline antibiotic as a model compound. The light dependent photocatalytic activity of CdS nanorods demonstrated that CdS nanorods possess higher catalytic efficiency in presence of blue light compared to white light toward the photocatalytic degradation of tetracycline antibiotic. We have also studied the photocatalytic activity in presence of various light intensity. These CdS nanorods exhibited the highest tetracycline degradation efficacy of 95.6% within 60 min in presence of blue light (intensity: 200W/m2) without any supplementary oxygen sources during the degradation reaction. The photocatalytic mechanism of the tetracycline degradation has been elucidated by scavenging experiment. The experimental results indicate the formation of reactive oxygen species during photocatalytic degradation of tetracycline antibiotic. This work represents an alternative route to develop heterogeneous photocatalyst for antibiotics degradation due to the outstanding efficiency and stability of the CdS nanorods as well as easy separation through simple filtration method. It is anticipated that this work will shed light in the practical applications of CdS nanorods for environmental remediation through wastewater treatment.