Researchers in the field of photocatalysis are interested in finding a solution to the problem of charge transfer and recombination in photodegradation mechanisms. The ideal photoactive catalyst would be inexpensive, environmentally friendly, easily manufactured, and highly efficient. Graphitic carbon nitride (g-C3N4) and metal oxide (MOx) based nanocomposites (g-CN/MOx) are among the photocatalysts that provide the best results in terms of charge transfer capacity, redox capabilities, and charge recombination inhibition. This article provides a comprehensive overview of the latest research on antibiotic removal from wastewater using photocatalysts based on g-C3N4 and metal oxides nanocomposites. Amoxicillin (AMX), Azithromycin (AZM), Cefixime (CFM), Ciprofloxacin (CIP), and Tetracycline (TC) are some of the common antibiotics that are the focus of this review article's examination of the photocatalytic behavior of various g-C3N4/metal oxide-based photocatalysts. A research gap demonstrates that many studies are required to use these nanocomposites for photodegradation of antibiotics. By providing a better grasp of the photocatalysis process, this review encourages scientists and researchers to develop an accurate and appropriate photocatalyst to reduce environmental risks. The main findings of this review article suggest that the cost-effective g-C3N4/MOx-based nanocomposites exhibit excellent photodegradation properties, high charge transfer, broadening light response, and charge separation. They promote enhanced charge transportation, superior electron conductivity, high redox capability, and suppressing charge recombination rate. The photodegradation mechanism involves various reactive oxygen species (ROSs), including superoxide radicals, hydroxyl radicals, and holes which promotes the photocatalysis process. The exact transportation mechanism of electrons and holes is unclear, but a rapid charge-carrier transit can significantly increase and speed up the photooxidation process.
Here, we report water purification through novel polyvinyl alcohol (PVA)-based carbon nanofibers synthesized through the electrospinning technique. In our novel approach, we mix PVA and tetraethyl orthosilicate (TEOS) with green tea solutions with different concentrations to synthesize carbon-based nanofibers (CNFs) and further calcine at 280 °C for carbonization. The scanning electron microscopy (SEM) results show the diameter of the nanofibers to be ∼500 nm, which decreases by about 50% after carbonization, making them more suitable candidates for the filtration process. Next, using these carbon nanofibers, we prepare filters for water purification. The synthesized CNF filters show excellent performance and successful removal of contaminants from the water by analyzing the CNF-based filters before and after the filtration of water through SEM and energy-dispersive X-ray (EDX) spectroscopy. Our SEM and EDX results indicate the presence of various nanoparticles consisting of different elements such as Mg, Na, Ti, S, Si, and Fe on the filters, after the filtration of water. Additionally, the SEM results show that PVA and TEOS concentrations play an important role in the formation, uniformity, homogeneity, and particularly in the reduction of the nanofiber diameter.