Ag/Bi4O5I2/reduced graphene oxide as a visible-light active nanophotocatalyst for pharmaceutical pollutants from wastewater

Novel plasmonic Ag-Bi4O5I2/carbonaceous nanocomposites (reduced graphene oxide [rGO]/walnut shell active carbon [WShAC]) were prepared through a sonication-mediated solvothermal process. Such materials were used for the photo-decomposition of several fluoroquinolone antibiotics, such as tetracycline hydrochloride, ofloxacin, and levofloxacin under simulated solar-light conditions (average intensity 2.960 W/cm2). The results of Brunauer-Emmett-Teller-Barrett-Joyner-Halenda (BET-BJH) in combination with field emission scanning electron microscopy, confirmed that carbonaceous materials could make suitable heterostructures with Bi4O5I2 using ultrasound waves, thereby increasing specific surface area from 20.3 m2/g for Bi4O5I2 to 35.6 m2/g for Ag-Bi4O5I2/WShAC and 40.6 m2/g for Ag -Bi4O5I2/rGO. Furthermore, the pore size of Bi4O5I2 increased from 9.1 nm to 21.6 nm when forming Ag -Bi4O5I2/rGO. Ag-Bi4O5I2/rGO indicated remarkable activity, achieving the degradation of 90.2% for tetracycline hydrochloride, 60.9% for ofloxacin, and 38.5% for levofloxacin after 180 min of simulated solar irradiation that made this sample to be chosen as a standout candidate for further investigation and potential applications. Concerning the constant rate for eliminating 50 mg/L of tetracycline, the constant rate was improved 2.25 and 4.75 times for Ag-Bi4O5I2/WShAC and Ag-Bi4O5I2/rGO, respectively. Also, the Ag-Bi4O5I2/rGO nano photocatalyst showed excellent stability after four cycles, in which the reusability dropped only 5%.& COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

Novel plasmonic Ag-Bi4O5I2/carbonaceous nanocomposites were prepared and used for the photo-decomposition of fluoroquinolone antibiotics. The carbonaceous materials significantly increased the specific surface area and pore size of Bi4O5I2, resulting in remarkable activity for degradation. The Ag-Bi4O5I2/rGO nano photocatalyst showed excellent stability and high reusability.