Enhanced Photocatalytic Efficacy and Stability in Antibiotic Pollution Mitigation Using BiVO₄ Nanoballs Encased in Ultrathin Polymeric g-C₃N₄ Nanocomposites under Visible Light Exposure

Abstract

Antibiotic overuse and indiscriminate disposal ultimately lead to overexploitation of the ecosystems expanding requirements, producing significant environmental and biological consequences. Advanced oxidation processes (AOPs) have kindled the interest of many researchers in targeting the destruction of antimicrobial and waterborne pollutants. As a result, an improvement of low-cost, high-efficiency photocatalysts for the successful decomposition of antibiotics is critical for the cleaning of harmful contaminants in rivers and lakes. In the current work, a simple hydrothermal approach was used to create the bismuth vanadate nanoballs (BiVO 4 ) anchored to the exterior of the ultrathin g-C 3 N 4 . It was named g-C 3 N 4 /BiVO 4 (X) (X = 5, 10, 15, and 20%) nanocomposites, and the photocatalytic removal of ciprofloxacin (CPX) and amoxicillin (AMX) was investigated using synthesized composites. According to the advanced characterization techniques, the synthesized composites exhibit superior purity and crystalline nature. The electron transfer occurring within the g-C 3 N 4 , in conjunction with the extension of BiVO 4 nanoballs, enhances the generation of photoexcited electron−hole (e − /h + ) pairs. This phenomenon contributes significantly to the improved photocatalytic activity observed in the g-C 3 N 4 /BiVO 4 system. Furthermore, the photocatalytic efficiency exhibited by g-C 3 N 4 /BiVO 4 (10%) nanocomposites in antibiotic removal surpasses that of both bare materials and other composite counterparts. The elimination of antibiotics was aided by reactive oxygen species (ROS) such as O 2 •− , h + , and OH. Finally, g-C 3 N 4 /BiVO 4 (10%), the intermediate byproduct of CPX and AMX decomposition, was discovered, and a probable CPX and AMX removal route was postulated. The g-C 3 N 4 /BiVO 4 (10%) composite exhibits long-term stability after five cycles. This study applies a green and ecologically responsive technique to the development of high-performance photocatalysts for wastewater remediation.