Photocatalytic degradation of antibiotics using bismuth oxybromide nanocomposites

The presence of antibiotics like tetracycline (TC) in water and wastewater is a global concern due to the potential harm they can cause to humans, animals, and the environment [1]. One effective method to reduce the amount of antibiotics in wastewater is through photodegradation by using photocatalysts such as Bismuth Oxy Bromide (BiOBr) [2]. In this study, BiOBr nanosheets were synthesized as photocatalysts using the hydrothermal method. To improve the photocatalytic activity and enhance the photodegradation of TC, BiOBr nanosheets/ZnIn₂S₄ (ZIS) nanosheets heterojunctions were synthesized at different mole ratios (BiOBr:ZIS) using the hydrothermal method. The structure optical features and electronic properties of the heterojunction were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-visible diffuse reflectance (DRS), Photoluminescence (PL) spectroscopy and Mott-Schottky spectroscopy. The study of TC photocatalytic degradation results showed that the BiOBr /ZIS heterojunction exhibited higher photocatalytic activity compared to pure BiOBr. This enhancement was attributed to the inhibition of charge carrier recombination, leading to a reduction in the recombination rate of electron-hole pairs. Also, a comparison between different samples demonstrated that the composite with a mole ratio of 1:16 (BiOBr:ZIS) has the highest degradation efficiency. Overall, the photocatalytic degradation process showed improvement, with the degradation efficiency increasing from 84.33% for BiOBr to 90.29% for BiOBr:ZIS at a ratio of 1:16.

Morasae Samadi obtained her BSc and MSc Degrees in organic chemistry from Sharif University of Technology (SUT), Iran, in 2005 and 2007, respectively. She received her PhD in Nanomaterials from SUT in 2013. Her work was focused on the photocatalytic property of 1D nanofibers. Afterwards, she joined the Nano, Energy, Surface and Thin films (NEST) group as a postdoctoral researcher to study 2D layered materials.  In 2017, she joined the Sharif Energy Research Institute (SERI) to do research and development in the application of nanotechnology in wastewater treatment, waste recycling, and recovery. Since February 2020, she has been an assistant professor of nanochemistry at Alzahra University. Her current research interests focus on the use of nanomaterials for water remediation and environmental applications.