Tailoring the structural and optical properties of sulphur doped g-C₃N₄ nanostructures and maximizing their photocatalytic performance via controlling carbon content

Carbon based materials are highly promising materials for environmental applications. In the current study, sulphur doped graphite like carbon nitride (S-g-C₃N₄) samples were prepared through thermal polymerization of thiourea at different conditions. The carbon content in the prepared samples was controlled by varying the calcination temperature and calcination time and its effect on the properties of the samples was investigated. The XRD studies confirmed the formation of g-C₃N₄ while the SEM investigations were performed to monitor the morphology transformation as a function of the preparation conditions. Changing the preparation temperature was found to strongly impact the carbon content in the g-C₃N₄ nanostructures and consequently their morphological and optical properties including their band gap and photoluminescence characteristics. Additionally, varying the calcination time was found to play a role in modifying the properties of the samples but with slightly less effect than that of the calcination temperature. These parameters were utilized to enhance the photocatalytic performance for water treatment applications. The findings of the study show that engineering the composition of S doped g-C₃N₄ samples by combining the effects of various preparation conditions could be effectively utilized to enhance the properties of g-C₃N₄ and its performance in many vital applications.