Visible light active CdS/CuO nanocomposites for photocatalytic degradation of ciprofloxacin, H2 production and antimicrobial activity

초록

In this study, cadmium sulfide/copper oxide (CdS/CuO) nanocomposite was synthesized by hydrothermal approach and used as a photocatalyst for ciprofloxacin (CIP) degradation, H2 production and antibacterial activity. The as-prepared nanocomposite was characterized with state-of-the-art analytical techniques. The BET surface area and bandgap energy of CdS/CuO nanocomposite were calculated to be 6.1 m2/g and 1.66 eV, respectively. The CIP degradation under visible light illumination by CdS/CuO nanocomposite was achieved to be 100 % under the experimental conditions of [CIP]0 = 10 mg/L, pH = 5.0, dosage of CdS/CuO = 0.5 g/L and time = 180 min. Interestingly, H2 production rate of 358.8 mu mol/h g- 1 was obtained by CdS/CuO under visible light illumination. Moreover, the CdS/CuO nanocomposite showed promising activity against E. coli. Based on the investigation of degradation intermediates as well as the ecotoxicity study, mainly four degradation products (DPs) formed via piperazine oxidation as well as ring opening reaction. Even though the parent compound did not show the ecotoxicity, the produced DP4 demonstrated much higher acute and chronic toxicity with LC50, EC50 and ChV. The present work suggests that developing a heterojunction of semiconductors is a viable strategy for enhancing their photocatalytic activities to purify water and generate green energy. Also, it suggests that toxicity study is an essential part to develop reliable treatment technologies for decomposing micropollutants in water.

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